CN101160898B - Timing synchronization and channel estimation at a transition between local and wide area waveforms using a designated TDM pilot - Google Patents

Abstract

Systems and methods are provided for channel estimation and timing synchronization in a wireless network. In an embodiment, a method is provided for time synchronization at a wireless receiver. The method includes decoding at least one TDM pilot symbol located at a transition between wide and local waveforms and processing the TDM pilot symbol to perform time synchronization for a wireless receiver. Methods for channel estimation at a wireless receiver are also provided. This includes decoding at least one TDM pilot symbol and receiving the TDM pilot symbol from an OFDM broadcast to facilitate channel estimation for a wireless receiver.

Description

The method and apparatus that timing is synchronous and channel is estimated that is used for the TDM pilot tone of the conversion place use appointment between local and wide area waveform

35 claim of priority according to U.S.C. § 119

The application requires in the U.S. Provisional Patent Application sequence number 60/660 of application on March 10th, 2005,720, be called the rights and interests of " TIME SYNCHRONIZATION ON BOUNDARY REGIONS INA WIRELESS COMMUNICATION NETWORK (timing in the cordless communication network on the borderline region is synchronous) ", its integral body is incorporated by reference thereto.

Technical field

This subject technology relate generally to communication system and method especially, relate to execution corresponding to the time synchronized of the enhancing of wireless network and the system and method for channel estimation.

Background technology

OFDM (OFDM) is a kind of method of numeral modulation, and wherein signal is divided into some narrow band channels with different frequencies.These channels are known as sub-band or subcarrier sometimes.This technology is contemplated to be the minimum interference with interchannel close to each other on the frequency at first during studying.In certain aspects, OFDM is similar to conventional frequency division multiplexing (FDM).Difference is the mode of the modulated and demodulation of signal.Normally, reducing to minimum for the interference among the channel that comprises data flow and code element or crosstalk gives preferentially.Improving separate channel then is not particular importance.

In a field, OFDM has been used to European digital audio broadcast services.This technology is applicable to Digital Television, and is being considered to a kind of method that obtains the high-speed digital data transmission by conventional telephone wire.It also uses in WLAN (wireless local area network).It is a kind of for the FDM modulation technique that transmits a large amount of numerical datas by radio wave that OFDM can be considered to, wherein OFDM is by being decomposed into radio signal a plurality of less subsignals or subcarrier work, and this subsignal or subcarrier are side by side sent to this receiver then on different frequencies.An advantage of OFDM technology is its amount that is reduced in the crosstalk in the signal transmission, current standard wherein, such as 802.11a WLAN, 802.16 and the WiMAX technology adopt various OEDM aspect.

In some systems of configuration OFDM technology, transmission is intended to side by side be used for many users.An above-mentioned example is broadcasting or multicast system.In addition, if different users can make one's options between the different piece of identical traffic, the data in each transmission are typically by Time Division Multiplexing.Common situation is, is intended to be organized into fixed structure for the data of transmission, such as, frame or superframe.Different user thereby can select go to receive the different part of a superframe in any specific time.In order to help timing and the frequency of most user's synchronized broadcasting signals, the pilot frequency code element of Time Division Multiplexing is inserted in each superframe beginning sometimes.In an above-mentioned situation, each superframe begins with a head, and this head is made up of two TDM pilot tones (being called TDM pilot tone 1 and TDM pilot tone 2) and other part.These code elements use to realize that by this system initial frame is synchronous, are also referred to as initial acquisition.

For further help time and/or Frequency Synchronization in a superframe, be also referred to as time or frequency-tracking, can use extra pilot frequency code element.Can use the pilot tone of frequency division multiplexing (FDM) to realize time and frequency-tracking, it can be embedded in each and send in the OFDM data code element.For example, if each OFDM code element is made up of N sub-carrier wave, the N-P in them can be used for transfer of data, can distribute to the FDM pilot tone and the P in them is individual.These P FDM pilot tones are evenly distributed on N the subcarrier sometimes, make per two pilot tones be decomposed by N/P-1 data subcarrier.The uniform subclass of such subcarrier is known as staggered in an OFDM code element.

The time domain channel estimation is used to the time tracking during a superframe.Time domain channel estimation is to obtain in the FDM pilot tone from be embedded in the OFDM data code element.This FDM pilot tone can be placed on all the time identical staggered on, perhaps they can occupy different staggered in different OFDM code elements.Subclass with subcarrier of index i+8k is called i sometimes and interlocks.In this case, N/P=8.In a situation, this FDM pilot tone can be placed on during the OEDM code element on staggered 2, is placed on during the code element secondarily on staggered 6, then, is placed on staggered 2, by that analogy again.This is known as (2,6) interval mode.In other example, this pilot interval pattern can be more complicated, makes staggered that this occupies be described as (0,3,6,1,4,7,2,5) pattern.This is known as (0,3,6) interval mode sometimes.Different interval modes makes this receiver can obtain the channel estimation longer than the tap of P time domain.For example, (2,6) interval mode can use to obtain the channel estimation of length 2P at receiver, and (0,3,6) interval mode can cause the channel estimation of length 3P.This is to be merged into longer channel estimation and to realize by observing from the channel of the length P of continuous OFDM code element in the unit that is called the time filtering unit.The estimation of longer channel can cause the timing synchronized algorithm that perfects more usually.

Some broadcast systems are intended to side by side be used for dissimilar transmission.For example, some broadcasting data can be used to any potential user in wide area network, and such data are known as the wide area content.Other data symbols that transmits at this network can only be used for current specific, the local user partly who resides in this network.Such data are known as the local content.This OFDM data code element that belongs to different content can be in a superframe in each frame by time division multiplexing.For example, some part of each frame in a superframe can be preserved for the wide area content, and other parts are used for local content.In the case, data and the pilot tone that is used to different content can be used the diverse ways scramble.In addition, the set of side by side broadcasting the transmitter of wide area and local content in a superframe can be different.Therefore, it is very common that the time domain channel estimation relevant with the wide area content and channel are observed, and the time domain channel relevant with local content estimated and the channel observation can be very different.

In above-mentioned situation, need the special strategy of employing for the channel estimation of the OFDM code element that accumulates in the boundary vicinity between wide area and the partial waveform.This is because observe and can not combine with channel observation from local code element with seamless way from the channel of wide-area symbols.Similarly concept is applicable to being positioned at behind this wavy boundary the time tracking of OFDM code element soon.If time tracking is based on time domain channel estimation, and if the individual channel estimation need then can not follow the tracks of the time of implementation during the first few OFDM code element after this wavy boundary from the sight of the OFDM code element of three orders.The channel estimation that therefore, may need to replace and simultaneous techniques regularly.

Summary of the invention

Below provide the simplification summary of various embodiment, in order to the basic understanding to some aspects of this embodiment is provided.This summary is not detailed general introduction.It is not attempted to determine the key element of key/critical or describes the scope of disclosed embodiment herein.Its unique purpose is to provide some concepts as the preamble that further describes that provides after a while with the form of simplifying.

For wireless network provides receiver processing unit and method.Except TDM pilot tone 1 and 2, the pilot frequency code element of at least one extra time-domain multiplexed (TDM) is processed on wireless receiver with other superframe code element and parameter, wherein carry out based on this extra pilot frequency code element such as time synchronized and channel estimation aspect, this extra pilot frequency code element can be called TDM3 or TDM pilot tone 3 in an example.In one embodiment, receiver components is provided, can consider the previous problem of not considering about timing and channel estimation, their parts that why is not considered are because the following fact: pilot frequency code element and relevant data are not can be in a similar manner by scramble to another (for example, wide area border is arrived in the part) from a wavy boundary.Provide character and the structure of the pilot frequency code element of increase, any side of the part that can occur in a Frame and wide area wavy boundary is carried out.

In another embodiment and as mentioned above, at least one extra TDM pilot frequency code element is increased to conventional broadcast symbol with interval conventional or that determine and gathers (for example, comprising the set of TDM1 and TDM2) in a superframe broadcasting.In this case, TDM3, TDM4 etc. pilot frequency code element can be added to an existing pilot set, estimating problem to alleviate with the timing in OFDM (OFDM) network that is used for the multi-medium data transmission of superframe tissue and channel, wherein the different part of superframe is used to different waveform transmission.For example, many TDM3 code elements can be processed on each border from the set of code element, and can be placed on the wavy boundary in this superframe so that synchronously and channel estimate.Be similar to TDM pilot tone 2, TDM pilot tone 3 (perhaps symbol subset) can be designed to provide regularly synchronously and channel is estimated, except depending on that position TDM pilot tone 2 in superframe is subject to wide-area channel and TDM pilot tone 3 both can be used for wide-area channel and also can be used for local channel.The structure of this TDM pilot tone 3 can be different from the structure of TDM pilot tone 2.If the conversion from the wide area waveform to partial waveform, it can be used for wide-area channel estimation or local channel estimation and timing to TDM pilot tone 3 (perhaps other extra pilot tones) in superframe.If this TDM pilot tone 3 is arranged in the conversion from the part to the wide area, it can be used for local channel estimation or wide area regularly and channel is estimated.

In order to realize above and relevant target, some illustrative embodiment is combined description herein with the following description book and subsidiary accompanying drawing.These aspects are represented and are covered all the whole bag of tricks that can put into practice this embodiment.

Description of drawings

Fig. 1 shows the schematic block diagram of the cordless communication network of the superframe structure that adopt to strengthen and receiver processing unit.

Fig. 2 shows an example superframe structure that adopts extra pilot frequency code element.

Fig. 3 shows the example modes of an extra pilot frequency code element.

Fig. 4 shows a selective embodiment, and wherein a plurality of TDM pilot tone 3 code elements are used between part and the wide area border.

Fig. 5 shows the example modes for extra timing pilot frequency code element.

Fig. 6 shows an example structure that is used for TDM pilot tone 3 code elements of reception.

Fig. 7 shows concept and example that is used for regularly synchronous channel estimation of channel segment (bin).

Fig. 8 shows the example block diagram of the timing synchronized algorithm on a relevant part/wide-area data border.

Fig. 9 shows an example pilot frequency code element that is used for wireless system and handles.

Figure 10 shows a schematic diagram that is used for the exemplary user equipment of wireless system.

Figure 11 shows the schematic diagram for the example base station of wireless system.

Figure 12 shows the schematic diagram for the example transceiver of wireless system.

Embodiment

Provide and in wireless network, be used for channel estimation and the synchronous system and method for timing.In one embodiment, provide a kind of method for time synchronized on radio receiver.This method comprises except TDM1 and TDM2, at least one new TDM pilot frequency code element of decoding, and handle this new TDM pilot frequency code element to carry out the time synchronized that is used for wireless receiver from the channel border of OFDM broadcasting.The method of the channel estimation that is used on wireless receiver also is provided.This comprises at least one new TDM pilot frequency code element of decoding, and from OFDM broadcast reception this new TDM pilot frequency code element so that estimate for the channel of wireless receiver.

In another embodiment, provide a kind of for the method for the data symbols of the border annex between the dissimilar traffic of the multicast wireless system that is positioned at the pilot frequency code element that divides multiplexing (TDM) in use being carried out channel estimation, time synchronized and AGC bootstrapping.This method comprises except TDM1 code element and TDM2 code element, determines the TDM pilot frequency code element that at least one is new.This method also is included in inserts at least one new TDM pilot frequency code element between two OFDM code elements of the broadcasting waveform that belongs to different, so that at the OFDM transmission block of decoding immediately before the border or after the border.New TDM pilot frequency code element can be used for channel estimation, time synchronized and be used for automatic gain control (AGC) bootstrapping or other side.

As using among the application, various radio communication terms are used.For wireless transmission, the relevant packet configuration that transmits can comprise OFDM (OFDM) code element, and it is made up of 4642 time domain baseband sampling values that are called the OFDM chip.Be 4096 data and the pilot chip that derives from 4096 data in the frequency domain and pilot sub-carrier in these OFDM chips.These chips are by with in 529 chips before the useful part and 17 chip period ground expansions after useful part.For the outer energy of the band that reduces ofdm signal, 17 chips and 17 last chips initial in an OFDM code element have the raised cosine envelope.Initial 17 chips of an OFDM code element are overlapping with 17 last chips of the OFDM code element before them.Therefore, the duration of each OFDM code element is that 4625 chips are long.

In a transmission of data packets example, data normally can be organized into superframe, and wherein each superframe has second duration.A superframe is made up of 1200 code elements of carrying out the OFDM modulation with 4096 subcarriers.With respect to subcarrier, the staggered subclass that refers to by certain amount (8 spacings) subcarrier at interval.For example, 4096 subcarriers can be divided into 8 and interlock, and wherein the subcarrier in i interlocks is the subcarrier with index 8k+i.Among 1200 OFDM code elements of a superframe, exist: two TDM pilot frequency code elements (TDM1, TDM2); Wide area and a local identities channel (WIC and LIC) code element; 14 overhead information symbols (OIS) channel symbol; 2,6,10 or 14 pilot frequency locations code elements (PPC) code element of variable number are used for helping the location; The pilot channel of some (TPC) code element, perhaps TDM3 pilot tone, it is located on each border between wide area and the local content-data; Remaining code element is used to the broadcasting of wide area or local waveform.Each superframe is made up of four Frames and overhead symbol.

Time Division Multiplexing pilot frequency code element 1 (TDM1) is an OFDM code element of each superframe, and wherein TDM1 is periodic, and has 128 OFDM chip period.This receiver uses TDM1 to be used for frame synchronization and initial time (running time) and frequency acquisition.What follow TDM1 is two code elements, and it carries wide area and local ID respectively.This receiver uses the corresponding PN sequence of this information utilization to carry out for appropriate the going of corresponding contents and disturbs operation.Time division multiplexed pilots code element 2 (TDM2) is followed wide area and local ID code element, and comprises for two cycles of part again, and wherein TDM2 is periodic, has 2048 OFDM chip period.When being identified for the timing accurately of demodulation OIS channel, this receiver uses TDM2.

What follow TDM2 is: a wide area TPC (WTPC) code element; Five wide area OIS code elements; Five wide area FDM pilot frequency code elements; Another WTPC; A local T PC (LTPC) code element; Five local OIS code elements; Five local FDM pilot frequency code elements; Another LTPC; With four Frames of following aforesaid 18 OFDM code elements at first.Frame is subdivided into wide-area data part and local data division.The wide area waveform is undetermined in advance, and additional with a wide area TPC at each end.This configuration also is used for local data's part.In this embodiment, each superframe exists 10 WTPC and 10 LTPC code elements altogether.

In another embodiment, the conversion of each between wide area drawn game domain waveform is relevant with single TPC pilot frequency code element.The structure of unique TPC pilot tone is different from the structure of WTPC or LTPC code element, because single pilot frequency code element is designed to satisfy channel estimation and the synchronisation requirement of wide area and local.In this embodiment, there are 11 TPC pilot tones (perhaps TDM pilot tone 3 code elements) altogether in each superframe.

As using in this application, term " parts ", " network ", " system ", " module " etc. are referred to the entity relevant with computer, the perhaps combination of hardware, hardware and software, software or software in commission.For example, parts can be, but are not limited to, thread, program and/or the computer of the process of moving at processor, processor, object, executable program, execution.As example, the application program and the equipment that move at communication equipment can be parts.One or more parts can reside in the thread of process and/or execution, and parts can be positioned on the computer, and/or are distributed between two or more computers.In addition, these parts can be carried out from the various computer-readable medium with storage various data structures thereon.These parts can be in the part and/or remote process communicate by letter, such as according to the signal with one or more packets (for example, in local system, distributed system from the data with the interactional parts of another parts, and/or on wired or wireless network, such as the internet).

Fig. 1 shows Radio Network System 100.This system 100 comprises one or more transmitters 110, and it is communicated by letter with one or more receivers 120 on wireless network.This receiver 120 can comprise the communication equipment of any kind substantially, such as, cell phone, computer, personal assistant, hand-held or laptop devices etc.This system 100 adopt a plurality of enhancings superframe parts 130 so that various in system 100 determine.May just adopt identical superframe structure 130 though should be noted in the discussion above that transmitter 110, different application datas can be in separately the structure relevant with each transmitter be sent out from separately transmitter.In one embodiment, the pilot frequency code element of at least one extra time-domain multiplexed (TDM) is added to the broadcast symbol set with interval routine or that determine in the superframe broadcasting that is described on 130.Therefore, TDM3, TDM4 (or more) pilot frequency code element can be added to an existing pilot set 130, to alleviate the borderline time between the wide area and local data waveform and channel estimation problem in OFDM (OFDM) network.

As will be described below in more detail, this extra code element is used as symbol subset at receiver 120 and handles, wherein this subclass can comprise one or more extra TDM3 code elements, and it is convenient to the symbol decoding of the data symbols of the boundary vicinity between part and wide-area data waveform.In an example, the symbol subset of two TDM3 can receive and handle at receiver 120, and wherein this subclass appears in superframe parts 130 between part and the wide area boundary position.Therefore, can provide various embodiment.In one embodiment, TDM pilot tone 3 code elements can be processed on each border of this superframe 130, and the structure of this pilot tone can be more complicated with processing on receiver 120.In other embodiment, except just in time after TDM pilot tone 2 and just in time (it is described in more detail with respect to Fig. 2) before the PPC code element, can adopt two (or more) TDM pilot tone 3 code elements (having simpler structure and processing procedure at this receiver) on most of borders.

Provide one or more receiver processing unit 140 with decoding superframe 140, and adopted the TDM pilot frequency code element that increases for the aspect of and channel estimation synchronous such as timing, wherein these parts 140 normally are illustrated and are applicable to specific receiver 120.For example, the timing based on TDM pilot tone 3 can be based in part on and principle like the syncsort of the TDM pilot tone of using during initial acquisition 2 synchronously.In addition, be used for to depend on whether adopt the single or first TPC of dicode in the wavy boundary based on the synchronous algorithm of the timing of TPC pilot frequency code element.But the parts 140 that are used for embodiment normally are more complicated, if especially there is single TPC pilot tone, because the pattern of the pilot interlace of using in single TPC code element situation is not normally fixed to another from a border.Therefore, it is relevant with the code element index that pattern separately can be confirmed as, and based on the supposition of this information and relevant channel position, these parts 140 on receiver 120 can be selected the suitable set of a combination coefficient.Based on analysis, depend on that the timing of the TDM pilot tone 3 that is arranged on the wavy boundary can expect to carry out at least the time tracking algorithm that the data symbols within wide area and local traffic piece is adopted synchronously.Except timing synchronously, the structure of TDM pilot tone 3 (the perhaps pilot frequency code element of other increases) allows to be used for the channel estimation of this code element, and it relies on the both sides on the border between wide area and the local data waveform.

In addition, this system 100 can comprise the pilot frequency code element agreement for wireless receiver.This can comprise the device that is used at least one extra pilot frequency code element of superframe for decoding, and wherein this extra pilot frequency code element is extra outside TDM1 and the TDM2 (for example, the demodulator of Reference numeral 120 as described below).In addition, this agreement comprise for the device that receives superframe in the wireless network (for example, mark 120) and for the treatment of this superframe to carry out channel estimation and at least one the device of (for example, mark 140) synchronously regularly.

Fig. 2 shows the superframe structure 200 of an example.Though in the superframe 200 of example, only show an extra pilot frequency code element TDM3, should be appreciated that, can adopt more than one extra pilot frequency code element.This superframe structure 200 introduces new OFDM code elements so that the broadcasting of a plurality of wide-area channel and a plurality of local channels in wireless network.First OFDM code element of superframe normally is the TDM pilot tone 1 on 210, and wherein second OFDM code element TDM pilot tone 2 is illustrated on 220.Being a TDM pilot tone 3 on 230 after this sequence, then is the wide area OIS (overhead information symbols) on 240.Normally, new local T DM pilot tone 3 code elements 230 can be inserted in before the local OIS code element.This pattern normally repeats at all nodes of wide area and local interchannel, for example on mark 250.But, should be noted in the discussion above that if having the symbol subset of at least two code elements is arranged on the border between wide area and the part, such as 250, then simpler processing can appear.Be similar to TDM pilot tone 2 220, TDM pilot tone 3 230 etc. can have staggered (1,3,5,7) of four empty odd numbers, and wherein even number staggered (0,2,4,6) is occupied by pilot tone.Different with TDM pilot tone 2 220, if be arranged in the conversion from the wide area to the part, TDM pilot tone 3 230 can adopt four even numbers three in staggered to be used for Local pilot, and one is used for wide area, if perhaps TDM pilot tone 3 is arranged in the conversion from the part to the wide area, then three are used for wide area pilot tone and one and are used for local.This also is applicable to the embodiment that adopts single TPC pilot tone on each border.In another embodiment, by means of each border two TPC code elements are set, the pilot channel of local transition (LTPC) code element had by interlocking that local FDM pilot tone occupies, and wide area TPC (WTPC) code element had by interlocking that wide area FDM pilot tone occupies.As will be appreciated, other configuration for superframe 200 is possible.

As a benchmark, each frame 200 can adopt 290 data code elements.Two new OFDM code elements, wide area 260 and local identities 270 channels (WIC and LIC) are introduced between the TDM1 and TDM2 of beginning of superframe 200.At these superframe 200 remainders, for example, introduce 20 TDM3 pilot frequency code elements 250.In another embodiment, introduce 11 TDM3 pilot frequency code elements.Usually, in the embodiment with two TDM3 pilot tones, there is the OFDM code element of two special uses in each conversion of wide area and local interchannel.But, can have exception.Before the PPC code element, represented as the short fragment of the TDM3 of 230 and 280 indications by being used for Fig. 2, only there is a TDM3 code element before in first wide area OIS code element (WOIS), and the ending at last frame.

Can increase new location pilot channel (PPC) 290, and its ending at this superframe comprises P OFDM code element.The place that this location pilot is searched receiver via triangulation method help.

Table 1: at the position that each border has TDM pilot tone 3 among the embodiment of two TPC code elements, W: the number of the wide-area symbols of every frame, P: the quantity of location pilot

Conversion	The code element index that is used for wide area TDM3 code element	The code element index that is used for local T DM3 code element
			TDM2→W-OIS	4	-
W-OIS→L-OIS	10	11
			L-OIS→W-Data	18	17
W-Data→L-Data	19+W+(F+4)*i， (i＝0，1，2，3)	20+W+(F+4)*i， (i＝0，1，2，3)
			L-Data→W-Data	18+(F+4)*i， (i＝1，2，3)	17+(F+4)*i， (i＝1，2，3)
L-Data→Pos.pilots	--	1199-P

More than the position of TDM3 code element has been shown in table 1, this embodiment has and both has wide area TDM pilot tone 3 code elements and also have local T DM pilot tone 3 code elements.The number of every frame useful data OFDM code element is represented that by F wherein W is used for wide-area channel, and (F-W) individual for local channel, wherein W is the scope from 0 to F.As previously mentioned, the fiducial value of F can be 290, and it is corresponding to the fiducial value of six location pilot (P=6).But, if do not use location pilot, should reserve 2 code elements by means of current numerology restriction at least.Work as P=2, the number of the code element of every frame can bring up to 291 from 290.A relational expression between F and P is provided by following:

$F=291-\frac{P-2}{4}$

Should be noted in the discussion above that from above description to TDM pilot tone 3 element positions, these TDM pilot tone 3 code elements can also be construed as the part of frame.Especially, the wide area TDM3 code element that frame 200 can be located from the outset begins, and ends at the local T DM3 code element at place, end, and can the conversion from wide area to local comprise two TDM3 code elements in this frame.By means of this, the number of every frame code element will be F+4, and it also is the factor in above table 1.Similarly, the TDM3 code element around OIS can be included among this OIS, cause 7 wide area OIS and 7 local OIS code elements, and each OIS phase place begins in the TDM3 code element and finishes.The part whether the TDM3 code element is considered to frame and OIS is conventional problem, but can also be driven to hardware provides convenience.In the embodiment with single TPC code element, thisly simply analogize and to allow, because except a frame that comprises F+3 code element (initial or last), there be F+2 code element in each frame usually.

Fig. 3 example shows the interleaving mode 300 that is used for occurring in the single TPC code element on the wavy boundary of an example.As mentioned above, a code element that is called TDM pilot tone 3 is used on each part/wide area and the wide area/local boundary.The structure of this code element is shown in Figure 3.Staggered 0,2 and 6 (in this example) are occupied by the wide area pilot tone respectively on 310,312 and 314.Staggered 4 is that Local pilot is used 320.Abbreviation " ctpn " is corresponding to channel estimation and timing wide area pilot tone.In other words, this staggered can use in the wide area mode by the channel estimation block as " previous code element " the FDM pilot interlace that is used for first wide-area symbols of demodulation, and also is used for regularly synchronously.Similarly, when obtaining " code element in the future " when channel is observed, " cp1 " expression is used for the pilot interlace of local channel estimation block.This observation is used to the last local traffic code element of demodulation.By the pilot interlace of " tp " expression be used to after the zone in the timing of data symbols synchronous.These staggered 310-320 separate by the sky that does not have energy to transmit is staggered.In order among all OFDM code elements (comprise and have the staggered code element that all occupy), to keep total transmission energy constant, the staggered factor of passing through of the non-zero in the TPC pilot tone

Scale up.When using the pilot tone of " cp1 " and " cpn " expression (especially, this implicit this receiver is known these borders the sixth of the twelve Earthly Branches), part and wide-area channel estimation block should be considered these problems.

Channel estimation pilot tone is followed the pattern that takies of adjacent corresponding traffic.In other words, in example 300, suppose to adopt (0,3,6) interval mode, and last local code element keeps staggered 1 to keep for pilot tone; Similarly, in wide area traffic zone, pilot tone should reside in first code element staggered 3 on.If use (0,3,6) pilot interval pattern, might on wide area and localized mass, all apply restriction, make they each be formed by the odd number code element.Like this, guarantee that the TDM3 pilot tone follows identical pattern, wherein the staggered of odd number is zero output.In the embodiment that adopts (2,6) interval mode, restriction is unnecessary like this, because the TDM3 pilot tone is all the time only in the staggered FDM pilot tone that comprises of even number.But, in this case, what " cp1 " staggered position can be from a wavy boundary to next wavy boundary.In keeping the TDM3 pilot tone, only occupy the staggered and demand adjusted of even number to certain advantage regularly is provided synchronously.That is, if odd number, rather than the staggered of even number be non-zero, the time-domain signal of generation no longer is periodic (be the negate of period 1 second round).This may make demodulation step complicated slightly, and still, this expense is unessential, and can consider such embodiment.

Fig. 4 shows a selective embodiment, has wherein used a plurality of TDM pilot tone 3 code elements.In this embodiment, two extra pilot frequency code elements are adopted on the border between part and wide-area data waveform.This illustrates 410 and 420, and wherein pilot channel (WTPC) code element of the pilot channel of local transition (LTPC) and wide area transition is shown as the subclass of code element.As shown on 420, such LTPC and WTPC grouping can appear in the OFDM transmission between the part and wide area waveform.In general, LTPC be used to the to decode last grouping of this local data's structure, wherein last local code element can be called local code element L.Therefore, receiver separately will be handled three code element packet, and it comprises local code element L, local code element L-1 and LTPC separately, to determine the channel estimation corresponding to last local code element L.First wide-area symbols N if decode, three code element packet that then are used for the receiver processing will be WTPC, first wide-area symbols N and next wide-area symbols N+1.Should be appreciated that, also can between part and wide-area data border, adopt plural TDM3 code element.

The code element structure (be used for LTPC and WTPC adopt) that is used for TDM3 is similar to the code element structure of general data code element.This comprises that it occupies eight time slots, and data symbols separately all was " 0 " before scramble, and wherein staggered is the subclass of carrier wave, and time slot is mapped to that this is staggered, in order to make staggered filling randomization.The scramble of surface acoustic wave (seed) and mask, time slot are to staggered mapping and modulated symbol energy and similar in data symbols.Specifically, use the wide area TDM3 of wide area ID code element one WTPC in surface acoustic wave, to carry out scramble, and use wide area ID and local ID that local TDM3 code element-LTPC is carried out scramble in surface acoustic wave.In general, in the modulator-demodulator embodiment of an example, receiver does not need to determine the position of TDM3, because it uses the FDM pilot tone they are common data symbols seemingly in separately LTPC or WTPC code element.Yet, transmission is about the very little expense of the informational needs of TDM3 position, and can be effective as one and be used for based on TDM3 that wakeup time is followed the tracks of and synchronous upgrading path regularly, wherein the TPC code element corresponding to following data content also is used for regularly synchronously.

For an embodiment who has single TPC code element and have (0,3,6) pilot interval pattern on the border, Fig. 5 shows possible timing pilot frequency mode 500.Hereinafter, be described in the processing procedure that needs in this certain embodiments, similarly method can be used for different embodiment simultaneously.In this pattern 500, white box is represented for regularly synchronous staggered (usually, this is staggered corresponding to following data content).If the number of the code element in wide area and local is specific forms 8n-1, the white on the non-zero of TDM pilot tone 3 is staggered and the pattern of black pilot tone can keep fixing (for example, as in Fig. 3).Because may not be this situation, can be same local four the different patterns 500 that arrive the example of wide area conversion that are used for.Corresponding to each of four different patterns in 500, can be slightly different by the demodulation techniques of regularly using synchronously.

Consideration timing in the conversion from the part to the wide area waveform in the embodiment with (0,3,6) pilot interval and single TPC code element that mentions is synchronous.(this is for more debatable situation synchronously regularly, because the channel of wide area estimation mother's collection of the channel of local estimation normally).In some wireless network, regularly normally estimate based on channel synchronously.Because the Local pilot of " cp1 " expression is twined by corresponding local channel in Fig. 3, their existence can't provide additional information in wide-area channel in receiving signal.Therefore, three pilot interlace can be used for regularly synchronously.This causes length is the estimation of 1536 wide-area channel.Should be noted in the discussion above that Local pilot only from the broadcasting of local emission machine, and the scramble that adopts for local also is specific.What therefore, all receivers can extract from above-mentioned Local pilot is the information of relevant local channel.

For the sake of simplicity, consider in Fig. 5 510 on pattern 2, it is consistent with Fig. 3.Can suppose that separating code elements for two is sent by linearity, one to have a wide area staggered, and another only has local staggeredly, and they are received afterwards experiencing different channel (wide area and part) respectively.This describes at Fig. 5, and it is described in greater detail below.Because interested is estimation wide-area channel h ⁿ(k), the staggered content (being represented by " x ") of the 4th reception is normally unessential.Reception is actually linear combination in this is staggered $\underset{i}{\mathrm{\Σ}}{P}_4^i\·H_4^{1,i}$ H wherein ₄ ¹, i represents that the 4th of i local channel is staggered.

Fig. 6 shows one for the structure 600 of the example of TDM pilot tone 3 code elements that receive.Notice, consider that in Fig. 6 non-zero is staggered, that is, the OFDM code element of reception be have two long be the periodic of cycle of 2048, it limits by non-zero is staggered.By the sampling one-period, non-zero is staggered catches from Fig. 3.At suitable (the wide area pilot tone) sampling, 2K-FFT with after going scramble, IFFT is performed.Usually, corresponding step is to adopt 2K-IFFT, and it is that cascade as four 512-IFFT realizes that four 512-IFFT back are phase ramp and 4 IFFT combiners.The output of considering 512-IFFT and phase ramp is worked to staggered i.If the channel estimation is based on the I pilot interlace, can estimate the channel of length I.NP so, wherein N _PThe=512nd, the number of the pilot tone that each is staggered.

In Fig. 6, I=3, and this is corresponding to the channel estimation of length 1536.The channel of the reality of being concerned about is that length is 4096 (identical with the length of the useful part of an OFDM code element).But in fact, the great majority in the channel tap of non-zero concentrate in the narrow zone.In one embodiment, suppose that the sum that postpones expansion (zone that is occupied by the channel tap of non-zero) is 768 chips at the most.The actual channel of this non-zero can appear between tap O and 4095 Anywhere.The another name version of the actual channel of length 4096 is represented in the estimation of length 1536.Total channel response of being concerned about (length 4096) can be divided into eight sections: 0 to 7, and wherein binary system k is made up of tap 512.k to 512 (k+1)-1.

Usually, the channel content of actual non-zero can the section of being positioned at k, k+1 and k+2, mould 8, and the estimation channel of length 1536 only covers three initial sections.The fragment position that depends on non-zero channel k, this channel enters in three sections of this estimation another name by means of different another name coefficients of utilization.In one embodiment, regularly be based on the place of the channel content of searching the non-zero in 4096 channel tap synchronously, and relevant that information and current suitable symbol timing.Owing to only can see the tap of 1536 orders, this channel inside can differently another name occur based on its wide position, need carry out some original hypothesis at (on section k, k+1 and k+2) on the channel position of routine.Suppose to have carried out some initial timing synchronously, this non-zero tap is the section of being present in (6,7,0) or (7,0,1) probably.This is presented at 710 of Fig. 7.The timing algorithm that depends on use, this takies and can be limited in (7,0,1), as Fig. 7 720 shown in; Otherwise, at time tracking (being also referred to as DMTT, perhaps the data pattern time tracking) before, carry out an extra processing procedure, to determine to take pattern.

In yet another embodiment, receiver can only use two in the middle of three pilot interlace of TDM pilot tone 3, specify to be used for time tracking, and the channel of estimation length 1024.Above-mentioned time domain channel estimation can be used for time tracking in the mode that is very similar to the time tracking of the routine of execution Anywhere in a frame.The algorithm that is used for above-mentioned time tracking is better simply, because the another name that occurs in this case use is the same for all channel segment.The advantage of using 1536 long channels estimations be its to carry out that time tracking changes for the very big time be more practical.

Hereinafter, described from three pilot interlace and obtained the process that length are 1536 channel estimation, and should be appreciated that, similarly to can be used for using two pilot interlace of TPC code element to obtain length be that 1024 channel is estimated to process.Get back to Fig. 6, for 0≤l≤I-1, by h _l(m) represent the l part (N of the channel impulse response of this estimation _PSample value is long), wherein l partly refers to the content from the l section, and when considering the channel impulse response of estimation, it can be confused.The single-tone of n observation on l is staggered thereby provided by following:

$\widehat{H_i}\left(n\right)=\frac{1}{\sqrt{N/2}}\&CenterDot;\underset{l=0}{\overset{I-1}{\mathrm{\&Sigma;}}}\underset{m=0}{\overset{N_P-1}{\mathrm{\&Sigma;}}}[h_l\left(m\right)\&CenterDot;e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2006800128992E00051.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}\frac{l\&CenterDot;i}{8}}]\&CenterDot;e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2006800128992E00051.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}\frac{n\&CenterDot;m}{N_P}}\&CenterDot;e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2006800128992E00051.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}\frac{i\&CenterDot;m}{N}},i=\mathrm{0,2,4,6}---\left(1\right)$

Scale factor come from implicit N/2 point FFT, it is divided into two steps: Np point EFT W _NP, the back is 4 FFT.Last factor representation phase ramp in (1), and the factor before it is corresponding to the suitable Np point FFT operation of obscuring the factor that has that applies at l channel strip.Therefore, at N _PPoint IFFT W _NP ^-1And remove phase ramp Θ from (1) _i ^-1Afterwards, remaining is that the time domain that 512 channel impulse response piece is formed is observed by the length of obscuring.With reference to (1), obscuring to observe and provided by following corresponding to staggered each of four non-zeros that occupied by TDM pilot tone 3:

${\hat{h}}_i={\mathrm{\&Theta;}}_i^{-1}\&CenterDot;W_{N_P}^{-1}\&CenterDot;{\hat{H}}_i=\frac{1}{2}\&CenterDot;\underset{l=0}{\overset{I-1}{\mathrm{\&Sigma;}}}{h}_l\&CenterDot;e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2006800128992E00051.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}\frac{l-\mathrm{<figure-callout\; id="8"\; label="i"\; filenames="S2006800128992E00081.png"\; state="\{\{state\}\}">i</figure-callout>}}{8}}=\frac{1}{2}\underset{k=0}{\overset{2}{\mathrm{\&Sigma;}}}{h}_{l_k}\&CenterDot;e^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="S2006800128992E00051.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}\frac{l_k-\mathrm{<figure-callout\; id="8"\; label="i"\; filenames="S2006800128992E00081.png"\; state="\{\{state\}\}">i</figure-callout>}}{8}},i=\mathrm{0,2,4,6}---\left(2\right)$

Here, ${\mathrm{\&Theta;}}_i=\mathrm{diag}{\left\{e^{-j\&CenterDot;2\mathrm{\&pi;}\frac{i\&CenterDot;m}{N}}\right\}}_{m=0}^{N_P-1}$ With

Be the vector of observing corresponding to the time-domain and frequency-domain pilot interlace, and as at 710 the l of Fig. 7 _kIndividual channel segment is non-NULL.For example, at 720 of Fig. 7, draw (l ₀, l ₁, l ₂)=(7,0,1).1/2 scale factor conduct

Obtain.Noticing that (2) provide four formula usually, still, on any example that provides, is to be occupied by " time pilot tone " (pattern among Fig. 5) four possible in the middle of staggered three.Therefore, last equation provides three formula by means of three unknown numbers in (2).In this case, as Fig. 7 720 shown in, unknown number is (h ₁, h ₀, h ₇).This system solves by 3 * 3 submatrixs of counter-rotating by 4 DFT matrixes removing i/2 capable (wherein i is the staggered index of black in Fig. 5) acquisition, and keeps row (l ₀, l ₁, l ₂) mod 4.For example, consider the pattern of the channel segment with hypothesis shown in Figure 7 (7,0,1).Be that 1536 channel impulse response h (n) is from corresponding to obtaining staggered 0,2 and 6 the observation as 720 the length of Fig. 7:

$\left[\begin{array}{c}{h}_7\\ h_0\\ h_1\end{array}\right]={\mathrm{\&Omega;}}_{4,\left[701\right]}^{-1}\&CenterDot;\left[\begin{array}{c}\hat{{\mathrm{<figure-callout\; id="0"\; label="h"\; filenames="S2006800128992E00031.png,S2006800128992E00051.png"\; state="\{\{state\}\}">h</figure-callout>}}_0}\\ \hat{{\mathrm{<figure-callout\; id="2"\; label="h"\; filenames="S2006800128992E00051.png"\; state="\{\{state\}\}">h</figure-callout>}}_2}\\ \hat{{\mathrm{<figure-callout\; id="6"\; label="h"\; filenames="S2006800128992E00051.png"\; state="\{\{state\}\}">h</figure-callout>}}_6}\end{array}\right],$ Wherein ${\mathrm{\&Omega;}}_{4,\left[701\right]}=\frac{1}{2}\&CenterDot;\left[\begin{array}{ccc}1& 1& 1\\ j& 1& -j\\ -j& 1& j\end{array}\right]---\left(3\right)$

Fig. 8 shows the block diagram of the timing synchronized algorithm 800 of an example.After applying a suitable initial offset, be identified for the initial sampling time of 2K-FFT module 810 based on previous timing.This skew is applied in be used to guaranteeing that sampled data positively represents the one-period of TDM pilot tone 3, and does not comprise the time domain chip from contiguous OFDM code element.Then, when applying correction of timing, this skew of initially deliberating is compensated.Then, be that timing search is carried out in the estimation of 1536 channel in length, so that position length is up to the non-zero channel content of the chip of 768 orders.In one embodiment, the accumulation window by sliding length 768 in the estimation of given channel and look for the above-mentioned peak response that adds up and carry out this search.In other example, this decision metric can be based on the energy that adds up in window and the linear combination that puts on the finite difference of this energy that adds up.This measure usually in the tap of first non-zero of huge channel energy or near will reach its maximum.This also is called and arrives at path (FAP) detection algorithm at first.In yet another embodiment, after calculating the energy curve that adds up that length is the channel tap in 768 the sliding window, receiver can be searched near the forward position in the spatial domain of the null character slope of ceiling capacity and back edge.These marginal positions can be converted into arriving at the path at first and arriving at position, path (FAP and LAP) at last of channel immediately.The information that this information can be associated with premeditated initial offset subsequently is combined, so that definite suitable time migration that will apply when the OFDM of processing sequence code element.

Some restrictions for algorithm 800 are, the actual delay expansion of channel on the horizon does not exceed half of estimation length, i.e. 768 in the present embodiment, and this channel segment that occupies is known in advance, referring to Fig. 7.Under these hypothesis, this timing performance depends on channel characteristics, and depends on 820 SNR from entrance to last block diagram 8.At this point, useful signal, namely each chip of channel estimation h (n) has the time identical power staggered with using all four of TDM pilot tones.As for noise, before arriving this point, it is by some modules, and the great majority among them are unified (in other words, they do not change this noise power).Multiply by Ω _{K, [...]} ^-1To change this noise power, because described this matrix is skimble-scamble.Can illustrate, for the combination of each possible staggered i, and the section l that occupies _k, corresponding Ω _kStrange (different) value be to be provided by [1,1,0.5].Therefore, at Ω _k ^-1Output 830 on noise variance improve (1+1+4)/3=2.Compare with the estimation of the channel that during initial meticulous timing, obtains, based on the channel estimation of TDM pilot tone 3 combined the quiescent dissipation of 3dB.But initial meticulous timing estimate is than the good 3dB of estimation that gathers in the channel estimation block, and therefore, meticulous timing search module 820 performance expections will not be inferior to the corresponding module that uses in data pattern is regularly followed the tracks of.Other module comprises FFT module 840 in the algorithm 800, goes to disturb module 850, IFFT module 860, spin matrix selector 870, phase ramp selector 880 and active staggered determiner 890.

Fig. 9 shows a pilot frequency code element process 900 that is used for wireless system.Though in order to explain for simplicity, this method is shown and described as a series of or a plurality of actions, should be understood that and understand, the processing procedure of Miao Shuing is not subject to the order of action herein, because from illustrate herein and describe, some action can be with different orders, and/or side by side take place with other action.For example, those skilled in the art will understand and understand, and method can be expressed as a series of relevant state or event mutually alternatively, such as in state diagram.In addition, can not need to carry out according to the action shown in all of the method for disclosed subject methods herein.

Proceed to 910, one or more superframe restrictions are in view of adopting extra TDM pilot frequency code element to determine.As mentioned above, this can comprise that element position, time slot mapping consideration, scramble consideration, mask consideration, time slot energy consideration, back compatible are considered and to the influence of current MAC layer framework.As will be appreciated, the modification that provides at the transmitter of OFDM broadcasting will be considered and explanation at receiver end.On 920, consider extra TDM pilot tone restriction.On the one hand, this can comprise that definite what extra code elements increase the code element set to traditional TDM1 and TDM2.

Normally, can comprise an extra TDM3, but more than one code element can be added to superframe and relevant standard.Other consideration is included in one or more restrictions of determining for whole superframe structure on 910.930, at least one extra TDM pilot frequency code element is added to superframe structure.As mentioned above, the first extra pilot tone is normally followed TDM2, and wherein follow-up extra pilot tone is used to the separation between part and the Wide-area Measurement Information broadcasting.As will be appreciated, other structure is possible.940, when extra pilot tone has been added to superframe, can carry out regularly synchronously at each receiver, channel estimation and/or AGC bootstrapping, each receiver obtains above-mentioned information in OFDM broadcasting.

Figure 10 is the example of the subscriber equipment 1000 that adopts under wireless communications environment according to one or more aspects of setting forth herein.Subscriber equipment 1000 comprises receiver 1002, and it receives signal from for example reception antenna (not shown), and carries out typical action (for example, filtering, amplification, down conversion etc.) to received signal, and this signal with good conditionsi of digitlization is to obtain sample value.Demodulator 1004 can be separated mediation the pilot frequency code element that receives is offered processor 1006 for the channel estimation.Processor 1006 can be to be exclusively used in the information that analysis is received by receiver 1002, and/or generation is used for the processor by the information of transmitter 1016 emissions, the processor of one or more parts of control subscriber equipment 1000, and/or both analyzed the information that is received by receiver 1002, produce the information that is used for by transmitter 1016 emissions, control the processor of one or more parts of subscriber equipment 1000 again.Subscriber equipment 1000 can comprise memory 1008 in addition, and it operationally is coupled to processor 1006.

Should be appreciated that, data storage (for example, memory) parts of describing herein can or volatile memory or nonvolatile memory, perhaps can comprise volatile and nonvolatile memory.As an example, rather than restriction, nonvolatile memory can comprise read-only memory (ROM), programmable read-only memory (PROM), EPROM (Erasable Programmable Read Only Memory) (EPROM), electrically-erasable ROM (EEROM) (EEPROM) or flash memory.Volatile memory can comprise random-access memory (ram), and it plays external cache.Limit as an example and not, RAM is available with many forms, such as, synchronous random access memory (SRAM), dynamic ram (DRAM), synchronous dram (SDRAM), double data rate SDRAM (DDRSDRAM), the SDRAM (ESDRAM), the Synchlink DRAM (SLDRAM) that strengthen and direct Rambus RAM (DRRAM).The memory 1008 of this thematic system and method is intended to comprise, and is not necessarily limited to, the memory of these and any other suitable type.

Figure 11 shows an example system 1100, it comprises the base station 1102 with receiver 1110 and transmitter 1124, receiver 1110 receives signal via a plurality of reception antennas 1106 from one or more subscriber equipmenies 1104, and transmitter 1124 passes the signal to one or more subscriber equipmenies 1104 via transmitting antenna 1108.Receiver 1110 can be from reception antenna 1106 reception information, and operationally relevant with demodulator 1112, the information that demodulator 1112 demodulation receive.The code element of demodulation is analyzed by processor 1114, and it is similar to aforesaid processor, and it is coupled to memory 1116.

Figure 12 illustrates the wireless communication system 1200 of a demonstration.For for purpose of brevity, wireless communication system 1200 is described a base station and a terminal.But, should be appreciated that this system can comprise more than one base station and/or more than one terminal, wherein extra base station and/or terminal substantially can be similar or be different from base station and the terminal of demonstration as described below.

With reference now to Figure 12,, on down link, at access point 1205,1210 receptions of emission (TX) data processor, format, coding, alternation sum modulation (perhaps symbol mapped) traffic data, and modulated symbol (" data symbols ") is provided.Symbol modulator 1215 receives and deal with data code element and pilot frequency code element, and code element stream is provided.Symbol modulator 1220 multiplex datas and pilot frequency code element, and they are offered transmitter unit (TMTR) 1220.Each transmit symbol can be data symbols, pilot frequency code element or zero signal value.Pilot frequency code element can send continuously at each code-element period.Pilot frequency code element can be frequency division multiplexing (FDM), OFDM (OFDM), Time Division Multiplexing, frequency division multiplexing (FDM) or code division multiplexing (CDM).

TMTR1220 receives and code element stream is transformed to one or more analog signals, and further limits (for example, amplification, filtering and frequency up-converted) this analog signal, is applicable to the down link signal that transmits at wireless channel with generation.Down link signal sends terminal to via antenna 1225 then.In terminal 1230, antenna 1235 receiving downlink signals, and the signal that receives offered receiver unit (RCVR) 1240.The signal giving condition of 1240 pairs of receptions of receiver unit (for example, filtering, amplification and frequency downconverted), and the signal that digitlization should limit is to obtain sampled value.The pilot frequency code element that symbol demodulator 1245 solution mediations will receive offers processor 1250 and is used for the channel estimation.Symbol demodulator 1245 further receives the frequency response estimation that is used for down link from processor 1250, the data that receive are carried out data demodulates, to obtain data symbols estimation (it is the estimation that sends data symbols), and the data symbols estimation is offered RX data processor 1255, its demodulation (namely, code element is gone mapping), this data symbols estimation of deinterleave and decoding, with the traffic data of recovering to transmit.The processing of being undertaken by symbol demodulator 1245 and RX data processor 1255 is respectively in access point 1205 and the processing complementation of being undertaken by symbol modulator 1215 and TX data processor 1210.

On up link, TX data processor 1260 processes traffic data and data symbols is provided.Symbol modulator 1265 receives and multiplexing data symbols with pilot frequency code element, carries out modulation, and code element stream is provided.Transmitter unit 1270 receive then and the transaction code flow filament to produce a uplink signal, this uplink signal sends access point 1205 to by antenna 1235.

At access point 1205, come this uplink signal of self terminal 1230 to handle to obtain sampled value by antenna 1225 receptions and by receiver unit 1275.Symbol demodulator 1280 is handled this sampled value then, and pilot frequency code element and the data symbols estimation of reception are provided for up link.RX data processor 1285 deal with data code elements estimate to recover the traffic data that transmitted by terminal 1230.Processor 1290 is carried out the channel estimation for each Active Terminal that transmits in up link.A plurality of terminals can be launched pilot tone in up link simultaneously on its pilot subband sets of distributing separately, wherein this pilot subband sets can be interlocked.

Processor 1290 and 1250 is indicated the operation on (for example, control, coordination, management etc.) access point 1205 and the terminal 1230 respectively.Processor 1290 separately and 1250 can be associated with program code stored and memory cell (not shown) data.Processor 1290 and 1250 can also be carried out calculating to derive frequency and the impulse response estimation for up link and down link respectively.

For multi-address system (for example, FDMA, OFDMA, CDMA, TDMA etc.), a plurality of terminals can transmit in up link simultaneously.For such system, this pilot subband can be shared at different terminal rooms.Cross over whole working band in the pilot subband that is used for each terminal and (under) the situation, can use the channel estimating techniques as much as possible, except this band edge.Such pilot subband structure will be that acquisition is desirable for the frequency diversity of each terminal.The technology of Miao Shuing can be realized by the whole bag of tricks herein.For example, these technology can realize with hardware, software or its combination.Realize for hardware, the processing unit that is used for the channel estimation can be realized in one or more application-specific integrated circuit (ASIC)s (ASIC), digital signal processor (DSP), digital signal processing appts (DSPD), programmable logic device (PLD), field programmable gate array (FPGA), processor, controller, microcontroller, microprocessor, other electronic unit is designed to carry out the function of describing herein, perhaps its combination.For software, enforcement can be via the module (for example, step, function etc.) of carrying out the function of describing herein.This software code can be stored in the memory cell, and is carried out by processor 1290 and 1250.

Realize that for software the technology of Miao Shuing can realize by means of the module (for example, step, function etc.) of carrying out the function of describing herein herein.This software code can be stored in the memory cell, and is carried out by processor.This memory cell can realize in processor or beyond processor, and in such cases, it can be via being coupled to processor communicatedly as the various devices that oneself knows in this field.

The embodiment that has comprised demonstration as mentioned above.Certainly, it is for describing for the parts for the purpose of describing this embodiment or each conceivable combination of method are impossible, and still, this area those skilled in the art can recognize, many other combinations and displacement are possible.Therefore, involved interior all such replacements, improvement and the variation of spirit and scope that drops on appended claim of these embodiment.In addition, thereby this term " comprises " or use in detailed description or this claim, such term is to be similar to the mode that this term " comprises " to comprise because when ought be in the claims adopting as the word of transition " comprising " explained.

Claims (32)

1. one kind is used for the synchronous method of timing on wireless receiver, comprising:

Reception has the Frame of at least one Time Division Multiplexing pilot frequency code element, and described at least one time division multiplexed pilots code element is in conversion place between wide area drawn game domain waveform; With

Handle described at least one TDM pilot frequency code element to determine channel estimating or at least one in synchronously regularly.

2. according to the method for claim 1, it is characterized in that, further comprise and handle described at least one TDM pilot frequency code element, the odd number relevant with described at least one TDM pilot frequency code element interlocked be set to zero.

3. according to the method for claim 1, it is characterized in that, further comprise receiving the Frame that comprises OFDM (OFDM) code element.

4. according to the method for claim 3, it is characterized in that, comprise that further staggered at least three the central even numbers of four even numbers that adopt described TDM pilot frequency code element are staggered, be used for the time synchronized of the OFDM code element after the wavy boundary.

5. according to the method for claim 3, it is characterized in that the step of described at least one the TDM pilot frequency code element of described processing further comprises by at least one fast Fourier transform (FFT) and at least one inverse fast Fourier transform (IFFT) to be carried out regularly synchronously.

6. according to the method for claim 5, it is characterized in that the step of described at least one the TDM pilot frequency code element of described processing further is included in provides pilot tone to remove to disturb component to handle the data from the FFT component between described FFT and the IFFT.

7. according to the method for claim 6, it is characterized in that the step of described at least one the TDM pilot frequency code element of described processing further is included in after the described IFFT definite and apply a phase ramp at staggered i place, wherein i is an integer.

8. according to the method for claim 7, it is characterized in that, the step of described at least one the TDM pilot frequency code element of described processing further be included in described determine and apply the step of a phase ramp after determine that at least one is corresponding to time domain and the staggered vector observed of pilot tone.

9. according to the method for claim 1, it is characterized in that, further comprise and adopt described at least one TDM pilot frequency code element to be used for the channel estimation.

10. according to the method for claim 9, it is characterized in that, further comprise one of described at least one TDM pilot frequency code element staggered frequency division multiplexing (FDM) pilot interlace that is treated to corresponding to the data content before the border, and will described at least one TDM pilot frequency code element another interlock and be treated to FDM pilot interlace corresponding to the data content after the border.

11. the method according to claim 1 is characterized in that, further comprises the interleaving mode according to described at least one the TDM pilot frequency code element of pilot interval mode treatment.

12. the method according to claim 1 is characterized in that, further comprises based on what wide area identifier (WID) drawn game relam identifier (LID) was identified for described at least one TDM pilot frequency code element going to disturb parameter.

13. the method according to claim 1 is characterized in that, further comprises the data of determining about described at least one TDM pilot frequency code element position.

14. a timing synchronization module that is used for wireless receiver comprises:

Acquisition component, for wireless receiver is sampled at least one Time Division Multiplexing pilot frequency code element, described at least one TDM pilot frequency code element is in conversion place between wide area drawn game domain waveform; With

At least one parts of decoding adopts described at least one TDM pilot frequency code element to carry out regularly synchronous or the channel estimation.

15. the module according to claim 14 is characterized in that, further comprises fast Fourier transform (FFT) element that is associated with described acquisition component.

16. the module according to claim 15 is characterized in that, wherein said acquisition component receives previous timing position information and applies an initial offset.

17. the module according to claim 16 is characterized in that, comprises that further processing removes to disturb parts from the pilot tone of the data of FFT component.

18. the module according to claim 17 is characterized in that, further comprises for the treatment of TDM pilot frequency code element index so that determine the device of effective pilot interlace.

19. the module according to claim 18 is characterized in that, described decoding parts comprise that further inverse FFT (IFFT) piece is to handle the data of removing to disturb parts from described pilot tone.

20. the module according to claim 19 is characterized in that, described decoding parts further comprise observes composition element to handle the data from described IFFT piece.

21. the module according to claim 20 is characterized in that, described decoding parts further comprise be used to applying the matrix rotary manipulation so that observe the device of combined treatment.

22. the module according to claim 21 is characterized in that, described decoding parts further comprise the phase ramp selector so that observe combined treatment.

23. the module according to claim 22 is characterized in that, further comprises meticulous timing block, with the data of processing from the observation composition element, and determines and the execution correction of timing.

24. the synchronous equipment of timing on wireless receiver comprises:

Be used for being placed in the frame decoding device of at least one Time Division Multiplexing pilot frequency code element of conversion place between wide area drawn game domain waveform;

Be used for receiving at wireless network the device of described frame; With

The device of at least one in synchronous with timing with the estimation of execution channel for the treatment of described TDM pilot tone.

25. an equipment that is used for time synchronized comprises:

For generation of the device that is placed at least one TDM pilot frequency code element of conversion place between the wide area drawn game domain waveform in OFDM broadcasting;

Be used for described at least one TDM pilot frequency code element is sent to the device of at least one receiver;

For the device of on described at least one receiver, described at least one TDM pilot frequency code element being decoded; With

Be used for based on described at least one TDM pilot frequency code element, carry out the device of regularly determining and proofreading and correct at described at least one receiver.

26. the equipment according to claim 25 is characterized in that, further comprises for the device of carrying out the channel estimation at described receiver.

27. an equipment that is used for time synchronized comprises:

Be used for the device that decoding is placed at least one TDM pilot field of conversion place between wide area drawn game domain waveform;

Be used for described at least one TDM pilot field is decomposed into the device of one or more staggered fields; And

For the treatment of the device of described staggered field with the correction of timing that is identified for wireless receiver.

28. the equipment according to claim 27 is characterized in that, further comprises for the treatment of described staggered field to determine the device of channel estimation at receiver.

29. a method that is used for the channel estimation on wireless receiver comprises:

Be placed at least one TDM pilot frequency code element of the conversion between wide area drawn game domain waveform from the OFDM broadcast reception; With

Decode described at least one TDM pilot frequency code element so that be used for the channel estimation of described wireless receiver.

30. one kind is used for the synchronous method of timing on wireless receiver, comprises:

Reception has the Frame of at least one the first Time Division Multiplexing pilot frequency code element that is associated with the local waveform and at least one the 2nd TDM pilot frequency code element that is associated with the wide area waveform; With

Handle a described TDM pilot frequency code element and described the 2nd TDM pilot frequency code element to determine time synchronized during Frame, described at least one TDM pilot frequency code element and described at least one the 2nd TDM pilot frequency code element are placed in conversion place between the wide area drawn game domain waveform in OFDM broadcasting.

31. the method according to claim 30, it is characterized in that, further comprise and handle three a code elements grouping, it comprises local code element L, local code element L-1 and the described first Time Division Multiplexing pilot frequency code element that is associated with the local waveform, so that be used for the channel estimation of local code element L or L-1.

32. the method according to claim 30, it is characterized in that, further comprise and handle three a code elements grouping, it comprises wide-area symbols N, wide-area symbols N-1 and the described second Time Division Multiplexing pilot frequency code element that is associated with the wide area waveform, so that be used for the channel estimation of wide-area symbols N or N-1.

Images