CN102724156B - Generation method as well as positioning method and device of time-division code-division orthogonal frequency division multiplexed signals - Google Patents
Generation method as well as positioning method and device of time-division code-division orthogonal frequency division multiplexed signals Download PDFInfo
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Abstract
The invention discloses a generation method as well as a positioning method and device of time-division code-division orthogonal frequency division multiplexed signals, and belongs to the field of communication. The method comprises the following steps: receiving a data stream, performing forward error correction coding and OFDM (orthogonal frequency division multiplexing) modulation on the data stream, generating OFDM signals, and generating first spreading codes; getting second spreading codes with the code length which is not less than 511 bits, and superimposing the OFDM signals with a plurality of the second spreading codes to get superimposed OFDM spreading codes; and generating TC (time division and code division)-OFDM signals according to the first spreading codes and the superimposed OFDM spreading codes. According to the method disclosed by the invention, the GOLD codes with the code length which is not less than 511 bits are utilized for correlation integration of a 25ms time slot, the correlation integration result is increased, the cross correlation suppression property of broadcast positioning signals is improved and the positioning precision is improved. Furthermore, through frequency division operation, the property of suppressing cross correlation interference of the generated positioning signals is jointly decided by two factors, the suppression of the cross correlation interference can be well improved.
Description
Technical field
The present invention relates to the communications field, particularly during one, demal divides generation method, localization method and the device of orthogonal frequency-division multiplex singal (TDMA CDMA-Orthogonal Frequency Division Multiplexing, TC-OFDM).
Background technology
In recent years, the progress of radiotechnics and wireless local area network technology and the increase of positioning service demand, promoted the development of location technology energetically, and the demand of people to indoor accurate position also grows with each passing day, particularly when tackling emergency, locating information seems particularly important especially.
The existing localization method based on mobile media broadcasting network; as shown in Figure 1; when generating broadcast positioning signals; the GOLD code in employing cycle 511 is as spreading code; its code check is 5M chips/sec; harbour part is the protection interval that 511 GOLD codes of 102.2us add 33.8us, amounts to 136us, and protection interval fills gained by first 169 of 511 GOLD codes.This spreading code is at full-time and OFDM (Orthogonal Frequency Division Multiplexing, OFDM) signal same frequency sending, mix with ofdm signal and be added, be modulated in certain carrier frequency, the framing signal of synthesizing the most at last is launched, for the acquisition and tracking of the receiver terminal of pseudo-random code ranging.
Realizing in process of the present invention, inventor finds that prior art at least exists following problem: the cross-correlation suppression characteristic in localization method is poor, and thus positioning precision is poor.
Summary of the invention
In order to improve the cross-correlation suppression characteristic in localization method, and improving positioning precision, embodiments providing a kind of method, localization method, device and the system that generate TC-OFDM signal.Described technical scheme is as follows:
On the one hand, provide a kind of generation method of TC-OFDM signal, described method comprises:
Receiving data stream, carries out forward error correction coding and OFDM modulation to described data flow, generates ofdm signal, and generates the first spreading code;
Obtain the second spreading code, from different frequencies, multiplication operation is done to described first spreading code, obtain the harbour of frequency division, and from different frequencies, multiplication operation is done to described second spreading code, obtain the spread-spectrum code signals of frequency division, and described ofdm signal is carried out superposing with multiple described second spreading code the spreading code obtaining superposing OFDM, described second spreading code is N position GOLD code, and described N is more than or equal to 511;
Spreading code according to described first spreading code and described superposition OFDM generates TC-OFDM signal;
Wherein, described ofdm signal is carried out superposing with multiple described second spreading code the spreading code obtaining superposing OFDM, specifically comprises:
The spread-spectrum code signals of described ofdm signal with multiple described frequency division is superposed, obtains the spreading code superposing OFDM.
Wherein, the described spreading code according to described first spreading code and described superposition OFDM generates TC-OFDM signal, specifically comprises:
The spreading code of the harbour of described frequency division and described superposition OFDM is modulated in carrier frequency and obtains modulation code;
Interval connection is carried out to described modulation code, generates TC-OFDM signal.
Wherein, described first spreading code is specially 511 GOLD codes that code check is more than or equal to 1M chips/sec, and described second spreading code is specially the GOLD code that code check is more than or equal to 1M chips/sec.
On the other hand, provide a kind of generating apparatus of TC-OFDM signal, described device comprises:
Code modulation module, for receiving data stream, carries out forward error correction coding and OFDM modulation to described data flow, generates ofdm signal, and generates the first spreading code;
Laminating module, for obtaining the second spreading code, and described ofdm signal is carried out superposing with multiple described second spreading code the spreading code obtaining superposing OFDM, described second spreading code is N position GOLD code, and described N is more than or equal to 511;
Generation module, for the spreading code of the described superposition OFDM that described first spreading code that generates according to described code modulation module and described laminating module obtain, generates TC-OFDM signal;
Frequency division module, for doing multiplication operation to described first spreading code from different frequencies, obtains the harbour of frequency division, and does multiplication operation to described second spreading code from different frequencies, obtains the spread-spectrum code signals of frequency division;
Correspondingly, described laminating module, specifically for the spread-spectrum code signals of described ofdm signal with multiple described frequency division being superposed, obtains the spreading code superposing OFDM.
Wherein, described generation module specifically comprises modulating unit and generation unit;
Described modulating unit, the spreading code of the described superposition OFDM obtained for the harbour of described frequency division that described frequency division module obtained and described laminating module is modulated in carrier frequency and obtains modulation code;
Described generation unit, for carrying out interval connection to described modulation code, generates TC-OFDM signal.
Wherein, described first spreading code is specially 511 GOLD codes that code check is more than or equal to 1M chips/sec, and described second spreading code is specially the GOLD code that code check is more than or equal to 1M chips/sec.
Another aspect, present embodiments provide a kind of localization method applying the generation method of above-mentioned TC-OFDM signal, described localization method comprises:
Transmitting terminal receiving data stream, carries out forward error correction coding and modulating in OFDM to described data flow, generates ofdm signal, and generates the first spreading code; Obtain the second spreading code, from different frequencies, multiplication operation is done to described first spreading code, obtains the harbour of frequency division, and from different frequencies, multiplication operation is done to described second spreading code, obtain the spread-spectrum code signals of frequency division; And described ofdm signal is carried out superposing with multiple described second spreading code the spreading code obtaining superposing OFDM, described second spreading code is N position GOLD code, and described N is more than or equal to 511; Spreading code according to described first spreading code and described superposition OFDM generates TC-OFDM signal, and broadcasts;
Receiving terminal is according to the described TC-OFDM signal of receive at least three different transmitting terminals, and the coordinate of described three different transmitting terminals positions receiving terminal;
Wherein, described ofdm signal is carried out superposing with multiple described second spreading code the spreading code obtaining superposing OFDM by transmitting terminal, specifically comprises:
The spread-spectrum code signals of described ofdm signal with multiple described frequency division superposes by described transmitting terminal, obtains the spreading code superposing OFDM.
Another aspect, present embodiments provides a kind of navigation system applying the generation method of above-mentioned TC-OFDM signal, and described navigation system comprises at least three different transmitting terminals and receiving terminal,
Described transmitting terminal, for receiving data stream, carries out forward error correction coding and modulating in OFDM to described data flow, generates ofdm signal, and generates the first spreading code; Obtain the second spreading code, from different frequencies, multiplication operation is done to described first spreading code, obtains the harbour of frequency division, and from different frequencies, multiplication operation is done to described second spreading code, obtain the spread-spectrum code signals of frequency division; And described ofdm signal is carried out superposing with multiple described second spreading code the spreading code obtaining superposing OFDM, described second spreading code is N position GOLD code, and described N is more than or equal to 511; Spreading code according to described first spreading code and described superposition OFDM generates TC-OFDM signal, and broadcasts;
Described receiving terminal, for the described TC-OFDM signal according to the different described transmitting terminal of at least three of receiving, and the coordinate of described three described transmitting terminals of difference positions receiving terminal;
Wherein, transmitting terminal, also for the spread-spectrum code signals of described ofdm signal with multiple described frequency division being superposed, obtains the spreading code superposing OFDM.
The beneficial effect that the technical scheme that the embodiment of the present invention provides is brought is: by utilizing code length for N (N>=511) GOLD code decorrelation integration 25ms time slot, increase correlation intergal result, improve the cross-correlation suppression characteristic of TC-OFDM signal, improve positioning precision.And operated by frequency division, the characteristic of the suppression cross-correlation interference of the TC-OFDM signal of generation is determined jointly by two factors, and the suppression of cross-correlation interference can better be improved.
Accompanying drawing explanation
In order to be illustrated more clearly in the technical scheme in the embodiment of the present invention, below the accompanying drawing used required in describing embodiment is briefly described, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.
Fig. 1 is the structural representation of the broadcast positioning signals that prior art provides;
Fig. 2 is the generation method flow diagram of the TC-OFDM signal that the embodiment of the present invention 1 provides;
Fig. 3 is the generation method flow diagram of the TC-OFDM signal that the embodiment of the present invention 2 provides;
Fig. 4 is the schematic diagram of the frequency division operation that the embodiment of the present invention 2 provides;
Fig. 5 is the structural representation of the TC-OFDM signal of the generation that the embodiment of the present invention 2 provides;
Fig. 6 is the structural representation of the generating apparatus of the TC-OFDM signal that the embodiment of the present invention 3 provides;
Fig. 7 is another structural representation of the generating apparatus of the TC-OFDM signal that the embodiment of the present invention 3 provides;
Fig. 8 is the flow chart of the localization method that the embodiment of the present invention 4 provides;
Fig. 9 is the structural representation of the navigation system that the embodiment of the present invention 5 provides.
Embodiment
For making the object, technical solutions and advantages of the present invention clearly, below in conjunction with accompanying drawing, embodiment of the present invention is described further in detail.
At present, various places TV station at different levels constitutes the CHINA RFTCOM Co Ltd spread all over the country already, CMMB/DAB (China Mobile Multimedia Broadcasting/Digital Audio Broadcasting, China Mobile multimedia broadcasting/digital audio broadcasting) exciter by broadcast type channel, for mobile phone television user provides the popular service such as TV, broadcast, urgent broadcast, web page browsing, weather forecast, stock market and government affairs information whenever and wherever possible.Therefore, mentality of designing of the present invention utilizes ubiquitous CHINA RFTCOM Co Ltd to position, and to save limited wireless communication resources, and reduces costs.
Embodiment 1
See Fig. 2, present embodiments provide a kind of generation method of TC-OFDM signal, described method comprises:
Step 101: receiving data stream, carries out forward error correction coding and OFDM modulation to data stream, generates ofdm signal, and generates the first spreading code;
Step 102: obtain the second spreading code, and ofdm signal is carried out superposing with multiple second spreading code the spreading code obtaining superposing OFDM, the second spreading code is N position GOLD code, and N is more than or equal to 511;
Step 103: the spreading code according to the first spreading code and superposition OFDM generates TC-OFDM signal.
The method that the present embodiment provides, the GOLD code decorrelation integration 25ms time slot being N (N>=511) by utilizing code length, increase correlation intergal result, improve the cross-correlation suppression characteristic of TC-OFDM signal, improve the accuracy of location simultaneously.
Embodiment 2
See Fig. 3, embodiments provide a kind of generation method of TC-OFDM signal, described method comprises:
201: receiving data stream, forward error correction coding and OFDM modulation are carried out to this data flow, generates ofdm signal;
Particularly, receive the data flow of input, forward error correction coding, intertexture and constellation mapping are carried out to this data flow, and the signal after constellation mapping is carried out OFDM modulation with scattered pilot together with continuous pilot multiple connection, generate ofdm signal.
Forward error correction coding, intertexture and constellation mapping are carried out to data stream, and to carry out OFDM modulation to data stream be existing more ripe technology, the embodiment of the present invention does not elaborate to it, the present invention is only with BPSK (Binary Phase Shift Keying, two-phase PSK) constellation mapping is that example is described, in practical application, QPSK (Quadrature Phase Shift Keying can be adopted, quarternary phase-shift keying (QPSK)) or 16-QAM (Quadrature Amplitude Modulation, quadrature amplitude modulation) constellation mapping.
202: generate the first spreading code, and obtain the second spreading code;
Wherein, this step and above-mentioned 201 does not have sequencing, and the first spreading code is the harbour part of each time slot of TC-OFDM signal, by utilizing first spreading code of short time, as CDMA signal, as the guiding of TC-OFDM signal.After generating TC-OFDM signal, when this TC-OFDM signal sends to receiver to position by transmitting terminal, essence when receiver can carry out pseudo-random code ranging according to this first spreading code is caught frequently.
The embodiment of the present invention does not limit the mode of generation first spreading code and the form of the first spreading code, this first spreading code can be GOLD code, the embodiment of the present invention is described for the GOLD code of the first spreading code for the cycle 511, in practical application, first spreading code also can be the GOLD code of other figure places, as 1023bit CDMA (Code Division Multiple Access, code division multiple access) spreading code, 127bit spreading code etc.Particularly, the first spreading code adopts code check to be 511 the GOLD codes being more than or equal to 1M chips/sec, can be applicable to the broadband range of 8M.The first spreading code employing code check in the present embodiment is 511 GOLD codes of 4M chips/sec, and harbour part is 136us, includes 544 chips, and wherein, front 511 chips are 511-GOLD codes; Rear 33 chips be the 1st chip of 511 yards to the 33rd chip, send TC-OFDM signal time, this first spreading code is full power transmissions.
Particularly, the second spreading code in the present embodiment adopts code length to be more than or equal to the long code of 511, this long code can be 511,1024 or 2047 etc., the present embodiment is described for the GOLD code of 2047, the GOLD code cycle of each 2047 is 511.75us, and code check is 4M chips/sec.
203: frequency division operation is carried out to the first spreading code and the second spreading code, obtain the harbour of frequency division and the spread-spectrum code signals of frequency division respectively;
Wherein, frequency division in this step is operating as preferred operations, as shown in Figure 4, the present embodiment proposes a kind of spread-spectrum code signals based on frequency division, effectively can suppress cross-correlation interference, namely all frequency division operation is carried out to the first spreading code and the second spreading code, obtain the harbour of frequency division and the spread-spectrum code signals of frequency division respectively, and carry out the spread-spectrum code signals of this frequency division and ofdm signal to superpose the spreading code obtaining superposing OFDM.
Wherein, the harbour that frequency division operation obtains frequency division is carried out to the first spreading code and is specially, the first spreading code is done multiplication operation from different frequencies, obtains the harbour after frequency division, in order to distinguish different base stations.The spread-spectrum code signals that frequency division operation obtains frequency division is carried out to the second spreading code, and the spread-spectrum code signals of frequency division and ofdm signal are carried out the spreading code that overlap-add operation obtains superposing OFDM, be specially, first the second spreading code is done multiplication operation from different frequencies, obtain the spread-spectrum code signals of frequency division, in order to distinguish different base stations, then the spread-spectrum code signals of frequency division and ofdm signal is carried out to mix the spreading code superposing and obtain superposing OFDM, and the spreading code of this superposition OFDM is modulated in certain carrier frequency, thus the signal exciter after modulation is launched.Wherein, the different frequency doing frequency division computing with the first spreading code is with to make the different frequency of frequency division computing identical with the second spreading code.
In practical application, the time of integration in Fig. 4 is that Tc, N get 1 to n and be used for distinguishing different spread-spectrum code signals.According to non-coherent integration values formula P=A
| sinc(fTc) |r (t), in formula, f is different frequency deviation, Tc is the time of integration, for the power spectrum of TC-OFDM, the power spectrum of the composite signal that the spread-spectrum code signals of different base station is corresponding is apart from one another by being 1/Tc, spread-spectrum code signals when a certain base station obtains this moment of maximum non-coherent integration values, and the non-coherent integration values of other spread-spectrum code signals is 0, thus effectively can suppress cross-correlation interference.
If do not perform frequency division operation, according to non-coherent integration values formula P=A to the first spreading code and the second spreading code
| sinc(fTc) |r (t), when frequency deviation is 0, non-coherent integration values just likely obtains maximum, only depends on this factor of correlation function R (t), namely, when R (t) shows as good autocorrelation and cross correlation, cross correlation value is smaller; When the autocorrelation showed and cross correlation difference, cross correlation value is larger.The suppression of the cross-correlation interference in the present embodiment is determined jointly by correlation function and sinc function two factors, and thus the suppression of cross-correlation interference can better be improved.
204: ofdm signal is carried out superposing with the spread-spectrum code signals of multiple frequency division the spreading code obtaining superposing OFDM;
Wherein, the overlap-add operation of the spread-spectrum code signals of ofdm signal and multiple frequency division, specifically comprise: choose GOLD code i.e. the second spreading code that code length is N (N>511), here be the GOLD code of 2047 for code length, cycle of spreading code of superposition OFDM is 24.864ms, and it is partially filled by following three: the 545th to the 2047th of (1) 2047 long code; (2) 2047 long codes circulated 47 complete cycles; The 1st to 1744 of (3) 2047 long codes.The spreading code of this 24.864ms filled, lower than harbour 20dB, is carried out frequency division operation, directly superposes the spreading code that can obtain superposing OFDM subsequently with ofdm signal by its gain.
In practical application, relevant with the GOLD code chosen to the quantity that ofdm signal carries out the second spreading code superposed, in a time slot, the quantity of the second spreading code is specially (a time slot duration-harbour the length)/GOLD code cycle, as for the GOLD code of 2047 that choose, the quantity of carrying out the second spreading code superposed with ofdm signal is specially (25ms-136us)/511.75us=48.6, that is, in a time slot, ofdm signal carries out superposing with the GOLD code of 49 2047 spreading code obtaining superposing OFDM, namely the GOLD code of 48 2047 complete cycles and the fractional chips of a GOLD code is had, the fractional chips of this GOLD code of the present embodiment is specially front 1744 chips of the GOLD code of 2047.Wherein first 2047 yards is only have chosen 545-2047, and rear 48 2047 long codes are pure 2047 GOLD codes.
Wherein, the present embodiment, in overlap-add operation, have employed long second spreading code, as CDMA code mixes with OFDM, improves the cross-correlation suppression characteristic of the TC-OFDM signal of generation.
205: the spreading code according to the harbour after frequency division and superposition OFDM generates TC-OFDM signal;
Particularly, the overlap-add operation in the present embodiment can carry out directly superposing with multiple second spreading code the spreading code obtaining superposing OFDM by ofdm signal, and the spreading code the first spreading code being superposed OFDM with this generates TC-OFDM signal; Also can be that the first spreading code and the second spreading code all do frequency division operation, overlap-add operation carries out superposing with the second spreading code after multiple frequency division the spreading code obtaining superposing OFDM by ofdm signal, thus modulation operations is carried out to the spreading code of the first spreading code after frequency division and superposition OFDM, generate TC-OFDM signal.
As shown in Figure 5, each time slot of the TC-OFDM signal that the present embodiment generates is made up of the spreading code of the first spreading code after a frequency division and a superposition OFDM, that is, TC-OFDM signal is formed by two parts GOLD code fusion that code bit is different, the first spreading code wherein after frequency division is the GOLD code of 511, superimposed code is be more than or equal to the GOLD code of 511, is made up of in a time slot the spreading code of the first spreading code after a frequency division and a superposition OFDM.
Particularly, the present embodiment has the gold code of 48 2047 complete cycles at a time slot 25ms, form with front 1744 chips in the 49th cycle, wherein first 2047 yards is only have employed 2047 yards the 545th to 2047, and rear 48 2047 long codes are pure 2047 GOLD codes.This second spreading code will full-time with ofdm signal same frequency sending, for the tracking of the receiver terminal of pseudo-random code ranging.Preferably, for ensureing that this spreading code does not produce interference to ofdm signal, the gain that this spread-spectrum code signals sends will lower than ofdm signal 20dB.
In practical application, with 511 GOLD code decorrelation integration 25ms time slot (high power harbour+superimposed code), correlation intergal result is: 20*log10 (511/33)=23.7981dB, and this correlation intergal result is the low numerical value of the maximum side peakedness ratio main peak value of auto-correlation function; And adopt the GOLD code being more than or equal to 511, as 2047gold code, the correlation intergal result that decorrelation integration 25ms time slot (high power harbour+superimposed code) obtains, higher than 511 numerical value obtained, the correlation intergal result obtained as 2047gold code is 20*log10 (2047/65)=30dB, it improves about 6.2db than 511, and cross-correlation suppression characteristic obtains obvious improvement.
In practical application, there is relational expression in signal bandwidth and spreading rate, BW=2Rc, BW are signal bandwidth, Rc is spreading rate, when the signal received is 8M bandwidth, and when the code check of spreading code is 5M chips/sec, the power spectrum of spread-spectrum signal is far beyond the broadband range of 8M, certain decline can be caused, affect the performance of receiver locating terminal, the present embodiment chooses the spreading code of suitable code check, substantially increases the performance of receiver locating terminal.
The method that the present embodiment provides, being more than or equal to 511 GOLD code decorrelation integration 25ms time slots by utilizing, increasing correlation intergal result, improve the cross-correlation suppression characteristic of TC-OFDM signal.And the present embodiment suppresses the characteristic of cross-correlation interference jointly to be determined by correlation function and sinc function two factors, and the suppression of cross-correlation interference can better be improved; In addition, the present embodiment have employed the spreading code that code check is 4M chips/sec, and the signal that can meet reception is the situation of 8M bandwidth, and the performance of receiver locating terminal improves.
Embodiment 3
See Fig. 6, present embodiments provide a kind of generating apparatus of TC-OFDM signal, described device comprises code modulation module 301, laminating module 302 and generation module 303,
Code modulation module 301, for receiving data stream, carries out forward error correction coding and OFDM modulation to data stream, generates ofdm signal, and generates the first spreading code;
Laminating module 302, for obtaining the second spreading code, and ofdm signal is carried out superposing with multiple second spreading code the spreading code obtaining superposing OFDM, the second spreading code is N position GOLD code, and N is more than or equal to 511;
Generation module 303, obtains for the first spreading code of generating according to code modulation module 301 and laminating module 302 spreading code superposing OFDM, generates TC-OFDM signal.
Wherein, see Fig. 7, described device also comprises frequency division module 304, this frequency division module 304 is for doing multiplication operation to the first spreading code from different frequencies, obtain the harbour of frequency division, and from different frequencies, multiplication operation is done to the second spreading code, obtain the spread-spectrum code signals of frequency division;
Correspondingly, laminating module 302 specifically for by the spread-spectrum code signals of ofdm signal and multiple frequency division with superpose, obtain the spreading code superposing OFDM.
Wherein, generation module 303 specifically comprises modulating unit and generation unit;
Described modulating unit, the spreading code of the superposition OFDM obtained for the harbour of frequency division that frequency division module 304 obtained and laminating module 302 is modulated in carrier frequency and obtains modulation code;
Described generation unit, for carrying out interval connection to modulation code, generates TC-OFDM signal.
Particularly, the first spreading code is specially the GOLD code that the code length that code check is more than or equal to 1M chips/sec is 511; Second spreading code is specially the GOLD code that code length that code check is more than or equal to 1M chips/sec is N (N>=511).The code length of the first spreading code adopted as, the present embodiment to be code check be 4M chips/sec is the GOLD code of 511, and the code length of the second spreading code of employing to be code check be 4M chips/sec is the GOLD code of N (N>=511).
It should be noted that: the generating apparatus of the TC-OFDM signal that above-described embodiment provides is when generating TC-OFDM signal, only be illustrated with the division of above-mentioned each functional module, in practical application, can distribute as required and by above-mentioned functions and be completed by different functional modules, internal structure by device is divided into different functional modules, to complete all or part of function described above.In addition, the generating apparatus of the TC-OFDM signal that above-described embodiment provides and the generation embodiment of the method for TC-OFDM signal belong to same design, and its specific implementation process refers to embodiment of the method, repeats no more here.
The device that the present embodiment provides, the GOLD code decorrelation integration 25ms time slot being N (N>511) by utilizing code length, increase correlation intergal result, improve the cross-correlation suppression characteristic of TC-OFDM signal, improve positioning precision.And operated by frequency division, the characteristic of the suppression cross-correlation interference of the framing signal of generation is determined jointly by two factors, and the suppression of cross-correlation interference can better be improved; In addition, the present embodiment have employed the spreading code that code check is 4M chips/sec, and the signal that can meet reception is the situation of 8M bandwidth, and the performance of receiver locating terminal improves.
Embodiment 4
See Fig. 8, present embodiments provide a kind of localization method applying the generation method of the TC-OFDM signal described in above-described embodiment 1 or 2, state localization method and comprise:
Step 401: transmitting terminal generates TC-OFDM signal, and broadcasts;
Step 402: receiving terminal is according to the TC-OFDM signal of receive at least three different transmitting terminals, and the coordinate of three different transmitting terminals positions receiving terminal.
Wherein, the embodiment of the present invention does not limit the mode of receiving terminal according to the coordinate receiving TC-OFDM signal acquisition transmitting terminal, its concrete steps can be technology contents disclosed in CN101616482A with reference to Chinese patent application publication number, the embodiment of the present invention is by three-point fix principle, and the coordinate according to three different transmitting terminals positions receiving terminal.
The localization method that the embodiment of the present invention provides, is received the TC-OFDM signal of transmitting terminal transmission, according to the distance of this TC-OFDM signal acquisition transmitting terminal to receiving terminal, thus according to three-point fix principle, can orient the position of receiving terminal by receiving terminal.
Embodiment 5
See Fig. 9, embodiments provide the navigation system of the generation method of the TC-OFDM signal of a kind of application as described in above-described embodiment 1 or 2, described navigation system comprises at least three different transmitting terminals 501 and receiving terminal 502,
Transmitting terminal 501, for generating TC-OFDM signal, and broadcasts;
Receiving terminal 502, for the TC-OFDM signal according to the different transmitting terminal of at least three of receiving, and the coordinate of three different transmitting terminals positions receiving terminal.
Wherein, the embodiment of the present invention does not limit the mode of receiving terminal according to the coordinate receiving TC-OFDM signal acquisition transmitting terminal, its concrete steps can be technology contents disclosed in CN101616482A with reference to Chinese patent application publication number, the embodiment of the present invention is by three-point fix principle, and the coordinate according to three different transmitting terminals positions receiving terminal.
The localization method that the embodiment of the present invention provides, is received the TC-OFDM signal of transmitting terminal transmission, according to the distance of this TC-OFDM signal acquisition transmitting terminal to receiving terminal, thus according to three-point fix principle, can orient the position of receiving terminal by receiving terminal.
It should be noted that: the device of the generation TC-OFDM method that above-described embodiment provides is when the location based on mobile media broadcasting network, only be illustrated with the division of above-mentioned each functional module, in practical application, can distribute as required and by above-mentioned functions and be completed by different functional modules, internal structure by device is divided into different functional modules, to complete all or part of function described above.In addition, the positioner based on mobile media broadcasting network that above-described embodiment provides belongs to same design with the localization method embodiment based on mobile media broadcasting network, and its specific implementation process refers to embodiment of the method, repeats no more here.
The invention described above embodiment sequence number, just to describing, does not represent the quality of embodiment.
One of ordinary skill in the art will appreciate that all or part of step realizing above-described embodiment can have been come by hardware, the hardware that also can carry out instruction relevant by program completes, described program can be stored in a kind of computer-readable recording medium, the above-mentioned storage medium mentioned can be read-only memory, disk or CD etc.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (8)
1. time, demal divides a generation method for orthogonal frequency-division multiplex singal, it is characterized in that, described method comprises:
Receiving data stream, carries out forward error correction coding and modulating in OFDM to described data flow, generates ofdm signal, and generates the first spreading code;
Obtain the second spreading code, from different frequencies, multiplication operation is done to described first spreading code, obtain the harbour of frequency division, and from different frequencies, multiplication operation is done to described second spreading code, obtain the spread-spectrum code signals of frequency division, and described ofdm signal is carried out superposing with multiple described second spreading code the spreading code obtaining superposing OFDM, described second spreading code is N position GOLD code, and described N is more than or equal to 511;
When generating according to the spreading code of described first spreading code and described superposition OFDM, demal divides OFDM TC-OFDM signal;
Wherein, described ofdm signal is carried out superposing with multiple described second spreading code the spreading code obtaining superposing OFDM, specifically comprises:
The spread-spectrum code signals of described ofdm signal with multiple described frequency division is superposed, obtains the spreading code superposing OFDM.
2. the method for claim 1, is characterized in that, the described spreading code according to described first spreading code and described superposition OFDM generates TC-OFDM signal, specifically comprises:
The spreading code of the harbour of described frequency division and described superposition OFDM is modulated in carrier frequency and obtains modulation code;
Interval connection is carried out to described modulation code, generates TC-OFDM signal.
3. the method for claim 1, is characterized in that, described first spreading code is specially 511 GOLD codes that code check is more than or equal to 1M chips/sec, and described second spreading code is specially the GOLD code that code check is more than or equal to 1M chips/sec.
4. time, demal divides a generating apparatus for orthogonal frequency-division multiplex singal, it is characterized in that, described device comprises:
Code modulation module, for receiving data stream, carries out forward error correction coding and modulating in OFDM to described data flow, generates ofdm signal, and generates the first spreading code;
Laminating module, for obtaining the second spreading code, and described ofdm signal is carried out superposing with multiple described second spreading code the spreading code obtaining superposing OFDM, described second spreading code is N position GOLD code, and described N is more than or equal to 511;
Generation module, for the spreading code of the described superposition OFDM that described first spreading code that generates according to described code modulation module and described laminating module obtain, during generation, demal divides OFDM TC-OFDM signal;
Frequency division module, for doing multiplication operation to described first spreading code from different frequencies, obtains the harbour of frequency division, and does multiplication operation to described second spreading code from different frequencies, obtains the spread-spectrum code signals of frequency division;
Correspondingly, described laminating module, specifically for the spread-spectrum code signals of described ofdm signal with multiple described frequency division being superposed, obtains the spreading code superposing OFDM.
5. device as claimed in claim 4, it is characterized in that, described generation module specifically comprises modulating unit and generation unit;
Described modulating unit, the spreading code of the described superposition OFDM obtained for the harbour of described frequency division that described frequency division module obtained and described laminating module is modulated in carrier frequency and obtains modulation code;
Described generation unit, for carrying out interval connection to described modulation code, generates TC-OFDM signal.
6. device as claimed in claim 4, it is characterized in that, described first spreading code is specially 511 GOLD codes that code check is more than or equal to 1M chips/sec, and described second spreading code is specially the GOLD code that code check is more than or equal to 1M chips/sec.
7. a localization method for the generation method of the TC-OFDM signal of application as described in any one of claim 1-3, it is characterized in that, described localization method comprises:
Transmitting terminal receiving data stream, carries out forward error correction coding and modulating in OFDM to described data flow, generates ofdm signal, and generates the first spreading code; Obtain the second spreading code, from different frequencies, multiplication operation is done to described first spreading code, obtains the harbour of frequency division, and from different frequencies, multiplication operation is done to described second spreading code, obtain the spread-spectrum code signals of frequency division; And described ofdm signal is carried out superposing with multiple described second spreading code the spreading code obtaining superposing OFDM, described second spreading code is N position GOLD code, and described N is more than or equal to 511; When generating according to the spreading code of described first spreading code and described superposition OFDM, demal divides OFDM TC-OFDM signal, and broadcasts;
Receiving terminal is according to the described TC-OFDM signal of receive at least three different transmitting terminals, and the coordinate of described three different transmitting terminals positions receiving terminal;
Wherein, described ofdm signal is carried out superposing with multiple described second spreading code the spreading code obtaining superposing OFDM by transmitting terminal, specifically comprises:
The spread-spectrum code signals of described ofdm signal with multiple described frequency division superposes by described transmitting terminal, obtains the spreading code superposing OFDM.
8. a navigation system for the generation method of the TC-OFDM signal of application as described in any one of claim 1-3, is characterized in that, described navigation system comprises at least three different transmitting terminals and receiving terminal,
Described transmitting terminal, for receiving data stream, carries out forward error correction coding and modulating in OFDM to described data flow, generates ofdm signal, and generates the first spreading code; Obtain the second spreading code, from different frequencies, multiplication operation is done to described first spreading code, obtains the harbour of frequency division, and from different frequencies, multiplication operation is done to described second spreading code, obtain the spread-spectrum code signals of frequency division; And described ofdm signal is carried out superposing with multiple described second spreading code the spreading code obtaining superposing OFDM, described second spreading code is N position GOLD code, and described N is more than or equal to 511; When generating according to the spreading code of described first spreading code and described superposition OFDM, demal divides OFDM TC-OFDM signal, and broadcasts;
Described receiving terminal, for the described TC-OFDM signal according to the different described transmitting terminal of at least three of receiving, and the coordinate of described three described transmitting terminals of difference positions receiving terminal;
Wherein, transmitting terminal, also for the spread-spectrum code signals of described ofdm signal with multiple described frequency division being superposed, obtains the spreading code superposing OFDM.
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| CN105355159A (en) * | 2015-09-30 | 2016-02-24 | 西安建筑科技大学 | High-precision underground scenic spot self-guide system and positioning method thereof |
| CN107181708B (en) * | 2017-05-22 | 2019-11-08 | 北京邮电大学 | Frequency estimating methods and location receiver |
| CN107835491B (en) * | 2017-10-16 | 2020-04-17 | 北京邮电大学 | UWB-based signal synchronization method and indoor positioning system |
| CN112703680B (en) | 2018-09-13 | 2023-02-24 | 中兴通讯股份有限公司 | System and method for transmitting uplink signal |
| CN111211807A (en) * | 2020-03-17 | 2020-05-29 | 南京凯瑞得信息科技有限公司 | Multi-channel carrier superposition multi-address access method and system |
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