Patent US5757858 - Dual-mode digital FM communication system

United States Patent m

Black et al.

US005757858A [li] Patent Number: [45] Date of Patent:

5,757,858 May 26, 1998

[54] DUAL-MODE DIGITAL FM COMMUNICATION SYSTEM

[75] Inventors: Peter J. Black. St. Lucia, Australia;

Nathaniel B. Wilson. San Diego. Calif.

[73] Assignee: Qualcomm Incorporated. San Diego, Calif.

[21] Appl. No.: 779,601
[22] Filed: Jan. 7, 1997

Related U.S. Application Data

[63] Continuation of Ser. No. 373,122, Dec. 23, 1994.

[51] Int CI.6 H04L 27/10; H04J 13/02;

H04B 1/04; H04B 1/16

[52] U.S. CI 375/295; 375/303; 375/324;

375/334; 375/344; 375/345; 375/200; 455/214; 455/234.1; 455/257; 341/68; 370/342

[58] Field of Search 375/200. 296,

375/272. 295. 303. 317, 324, 327, 334, 344. 345; 370/335, 342. 441. 479; 455/132. 142. 143, 205, 214, 234.1. 235.1. 257;

332/100; 341/68. 70

[56] References Cited

U.S. PATENT DOCUMENTS

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4,603,300 7/1986 Welles, II et al 455/214

4,675,882 6/1987 Lfflieetal 375/324

4,776,039 10/1988 Akaiwa 455/205

4,878,035 10/1989 Vendely et al 375/303

4,944,025 7/1990 Gehring et al 455/209

5,003,621 3/1991 Gailus 455/316

5,010,585 4/1991 Garcia 375/216

5,107,225 4/1992 Wheauey, HI et al 330/279

5,111,163 5/1992 Edich 375/271

5,151,923 9/1992 Fujiwara 375/216

5,163,159 11/1992 Rich et al 455/214

(List continued on next page.)

FOREIGN PATENT DOCUMENTS

0507401 10/1992 European Pat. Off. H03J 7/02

0508401 10/1992 European Pat. Off. H04L 27/14

9103871 3/1991 WIPO H03D 1/00

9210028 6/1992 WIPO H03G 3/30

9426024 11/1994 WIPO H04L 27/22

9530275 11/1995 WIPO H03G 3/30

Primary Examiner—Stephen Chin

Assistant Examiner—Jeffrey W. Gluck

Attorney, Agent, or Firm—Russell B. Miller; Roger W.

Martin

[57] ABSTRACT

A dual-mode digital communication system for communicating an information signal during operation in frequencymodulated (FM) and multiple-access modes is disclosed herein. The digital communication system includes a dualmode transmitter for transmitting the information signal using an FM communication signal during FM mode operation, and for transmitting the information signal using a multiple-access communication signal during multipleaccess mode operation. The communication system further includes a dual-mode receiver for receiving the FM communication signal during FM mode operation, and for receiving the multiple-access communication signal during multiple-access mode operation. Incorporated within the dual-mode receiver is a digital demodulator for recovering the information signal from the received FM signal during operation in the FM mode, and for recovering the information signal from the received multiple-access signal during multiple-access mode operation. In a preferred implementation the dual-mode transmitter is disposed to convert a first sequence of binary data within the information signal into a sampled modulation waveform, and to provide the FM communication signal by modulating a carrier signal based at least in part on the sampled modulation waveform. The dual-mode transmitter may also be configured to multiplex a second sequence of wideband message data with the sampled modulation waveform so as to form a composite FM modulation waveform.

6 Claims, 24 Drawing Sheets