Low complexity maximum likelihood detection of concatenated space codes for wireless applications

• US 7,643,568 B2
• Filed: 12/21/2004
• Issued: 01/05/2010
• Est. Priority Date: 10/31/1997
• Status: Expired due to Fees

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Inventors: Poon, Patrick, Alamouti, Siavash, Tarokh, Vahid
• Primary Examiner(s): Ghebretinsae; Temesghen
• Application Number:
  US11/018,780
• Publication Number:
  US 20050105630A1
• Time in Patent Office: 1,841 Days
• Field of Search: 375/265, 375/267, 375/260, 375/295, 714/792, 714/786
• US Class Current: 375/267
• CPC Class Codes: H03M 13/256 with trellis coding, e.g. with convolutional codes and TCM
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04L 1/0054 Maximum-likelihood or sequential decoding, e.g. Viterbi, Fano, ZJ algorithms
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/006 Trellis-coded modulation
• CPC Class Codes: H04L 1/0065 Serial concatenated codes
• CPC Class Codes: H04L 1/0618 Space-time coding
• CPC Class Codes: H04L 1/0625 Transmitter arrangements
• CPC Class Codes: H04L 1/0631 Receiver arrangements
• CPC Class Codes: H04L 25/03178 Arrangements involving sequence estimation techniques
• CPC Class Codes: H04L 25/03331 Arrangements for the joint estimation of multiple sequences

Abstract

Good transmission characteristics are achieved in the presence of fading with a transmitter that employs a trellis coder followed by a block coder. Correspondingly, the receiver comprises a Viterbi decoder followed by a block decoder. Advantageously, the block coder and decoder employ time-space diversity coding which, illustratively, employs two transmitter antennas and one receiver antenna.

Claims

1. A mobile device comprising:

a receiving antenna to receive incoming codes generated based on concatenated trellis and space-time block coding and transmitted by two or more transmitting antennas;

a space-time block combiner coupled to the receiving antenna to combine the incoming codes that were transmitted from the two or more transmitting antennas; and

a decoder responsive to output signals of the space-time block combiner.

2. The mobile device of claim 1 wherein the incoming codes include a first symbol and a second symbol and a third symbol generated using a complex conjugation of one of the first symbol and the second symbol and a fourth symbol generated using a negative complex conjugation of another of the first symbol and the second symbol.

3. The mobile device of claim 1, wherein the decoder is a Viterbi decoder and the incoming codes are decoded using at least the space-time block combiner and the Viterbi decoder.

4. In a wireless communication system, a method of communicating information over a wireless link, the method comprising:

receiving incoming codes generated based on concatenated trellis and space-time block coding;

performing a first decoding of the incoming codes, wherein the first decoding includes combining at least a first incoming code and a second incoming code together to form one or more signals; and

performing a second decoding, wherein the second decoding includes applying Viterbi decoding to the one or more signals.

5. The method of claim 4 wherein the first incoming code is received at a first time, and wherein the second incoming code is received at a second time distinct from the first time.

6. The method of claim 4 where the Viterbi decoding includes generating a separate metric for soft decision of an incoming code.

7. The method of claim 4, wherein the first incoming code includes a first symbol and a second symbol and wherein the second incoming code includes a third symbol generated using a negative complex conjugation of the second symbol and a fourth symbol generated using a complex conjugation of the first symbol.

8. The method as recited in claim 7 wherein the first and third symbols are transmitted, respectively, at a first time and at a second time distinct from the first time, from a first antenna, and the second and fourth symbols are transmitted, respectively, at the first and second times from a second antenna.

9. In a wireless communication system, a method of communicating information over a wireless link, the method comprising:

generating complex numbers that represent constellation symbols including a first and a second symbol; and

producing a block code including the first and second symbol and a third symbol generated using a negative complex conjugation of the second symbol and a fourth symbol generated using a complex conjugation of the first symbol.

10. The method of claim 9 wherein the complex numbers that represent constellation symbols are generated, at least in part, using a trellis code modulation (TCM) encoder.

11. The method as recited in claim 9 further comprising transmitting the first and third symbols, respectively, at a first time and at a second time distinct from the first time, from a first antenna, and transmitting the second and fourth symbols, respectively, at the first and second times from a second antenna.