Method and constructions for space-time codes for PSK constellations for spatial diversity in multiple-element antenna systems

• US 20040146014A1
• Filed: 01/13/2004
• Published: 07/29/2004
• Est. Priority Date: 09/18/1998
• Status: Active Grant

• Current Assignee: DIRECTV, LLC (AT&T, Inc.)
• Original Assignee: Hughes Electronics Corporation (AT&T, Inc.)
• Inventors: Hammons, A. Roger Jr., Gamal, Hesham El
• Granted Patent: US 7,324,482 B2
• Time in Patent Office: Days
• US Class Current: 370/320
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/0065 Serial concatenated codes
• CPC Class Codes: H04L 1/0618 Space-time coding
• CPC Class Codes: H04L 27/18 Phase-modulated carrier systems, i.e. using phase-shift keying H04L27/32 takes precedence

Abstract

General binary design criteria for PSK-modulated space-time codes are provided. For linear binary PSK (BPSK) codes and quadrature PSK (QPSK) codes, the rank (i.e., binary projections) of the unmodulated code words, as binary matrices over the binary field, is used as a design criterion. Fundamental code constructions for both quasi-static and time-varying channels are provided.

Claims

1. A communication system comprising:

a framer for segmenting transmit data blocks into fixed frame lengths for generating information symbols from a discrete alphabet of symbols;

a plurality of antenna links;

a channel encoder for encoding the generated information symbols with an error control code for producing code word symbols;

a spatial formatter for parsing the produced code word symbols to allocate the symbols to a presentation order among said plurality of antenna links; and

a phase shift keying modulator for mapping the parsed code word symbols onto constellation points from a discrete complex-valued signaling constellation according to binary projections to achieve spatial diversity.

2. A communication system as recited in claim 1 comprising data terminal equipment (DTE) coupled to said framer for communicating digital cellular data blocks.

3. A communication system as recited in claim 2 wherein said digital cellular data terminal equipment comprises Code Division Multiple Access (CDMA) systems.

4. A communication system as recited in claim 2 wherein said digital cellular data terminal equipment comprises Time Division Multiple Access (TDMA) systems.

5. A communication system as recited in claim 1 wherein said channel encoder comprises a mobile channel encoder producing the code word symbols having length of a multiple N of the number of said plurality of antenna links L.

6. A communication system as recited in claim 5 wherein said spatial formatter parses the length N of the produced code word symbols among L antennas.

7. A communication system as recited in claim 2 comprising a plurality of transmit antennas, wherein the combination of channel encoder and spatial formatter are chosen from the class of space-time codes satisfying a binary rank criteria.

8. A communication system as recited in claim 2 comprising a plurality of transmit antennas, wherein the combination of channel encoder and spatial formatter are provided with a stacking space-time code construction.

9. A communication system as recited in claim 2 comprising a plurality of transmit antennas, wherein binary phase shift keying (BPSK) modulation is used and the space-time code is based on formatting the output of convolutional channel encoder for presentation across the transmit antennas.

10. A communication system as recited in claim 2 comprising a plurality of transmit antennas, wherein a concatenated space-time code is used in which the outer code is used to satisfy a binary rank criteria and multiple inner codes are used to encode the transmitted information from the multiple transmit antennas.

11. A communication system as recited in claim 2 comprising a plurality of transmit antennas, wherein a concatenated space-time code is used in which the inner code is composed of a channel encoder and a spatial formatter designed to satisfy a binary rank criteria.

12. A communication system as recited in claim 2 comprising a plurality of transmit antennas, wherein the combination of channel encoder and spatial formatter are covered by a multi-stacking construction.

13. A communication system as recited in claim 2 comprising a plurality of transmit antennas, wherein quadrature phase shift keying (QPSK) modulation is used and the space-time code is covered by a stacking, multi-stacking, or de-stacking constructions for QPSK.

14. A communication system as recited in claim 2 comprising a plurality of transmit antennas, wherein QPSK modulation is used and the space-time code is based on formatting the output of a linear convolutional code over the ring of integers modulo 4 for presentation across the multiple transmit antennas.

15. A communication system as recited in claim 2 comprising a plurality of transmit antennas, wherein QPSK modulation is used and the space-time code employs a dyadic construction.

16. A communication system as recited in claim 2 comprising a plurality of transmit antennas, wherein multi-level coded modulation and multi-stage decoding are used and the binary space-time code employed in each level belongs to the class of codes that satisfy the binary rank criterion or any of the constructions.

17. A communication system as recited in claim 2 comprising two transmit antennas wherein M-ary P5K modulation, M=8 or more, is used and the space-time code belongs to a class satisfying the binary rank criteria or any of the constructions.

18. A communication system as recited in claim 2 comprising a plurality of transmit antennas, wherein graphical space-time codes are designed such that the code generating matrix satisfies the stacking, multi-stacking, or de-stacking construction.

19. A communications method comprising:

generating information symbols for data block frames of fixed length;

encoding the generated information symbols with an underlying error control code to produce the code word symbols;

parsing the produced code word symbols to allocate the symbols in a presentation order to a plurality of antenna links;

mapping the parsed code word symbols onto constellation points from a discrete complex-valued signaling constellation;

transmitting the modulated symbols across a communication channel with the plurality of antenna links;

providing a plurality of receive antennas at a receiver to collect incoming transmissions; and

decoding received baseband signals with a space-time decoder.

20. A method as recited in claim 19 wherein said encoding and parsing steps are performed with a space-time encoder having a channel encoder and a space-time formatter.

21. A communications system comprising:

means for generating information symbols for data block frames of fixed length;

means for encoding the generated information symbols with an 5 underlying error control code to produce the code word symbols;

means for parsing the produced code word symbols to allocate the symbols in a presentation order to a plurality of antenna links;

means for mapping the parsed code word symbols onto constellation points from a discrete complex-valued signaling constellation;

means for transmitting the modulated symbols across a communication channel with the plurality of antenna links;

means for providing a plurality of receive antennas at a receiver to collect incoming transmissions; and

means for decoding received base band signals with a space-time decoder.

22. A communication system as recited in claim 21 wherein said encoding means comprises a mobile channel encoder producing the codeword symbols having length of a multiple N of the number of said plurality of antenna links L.

23. A communication system as recited in claim 22 wherein said parsing means comprises a spatial formatter for parsing the length N of the produced code word symbols among L antennas.

24. A communication system as recited in claim 21 wherein said encoding and parsing means comprise a space-time encoder having a channel encoder and a space-time formatter.

25. A communication system as recited in claim 24 comprising receiving means for collecting incoming transmissions demodulated with a phase shift keying demodulator and a space-time decoder to demodulate the code word symbols.