High rate reed-solomon concatenated trellis coded 16 star QAM system for transmission of data over cellular mobile radio

• US 5,838,728 A
• Filed: 05/06/1997
• Issued: 11/17/1998
• Est. Priority Date: 11/23/1994
• Status: Expired due to Term

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: AT&T Wireless Services Incorporated (AT&T, Inc.)
• Inventors: Haymond, William D., Wright, Andrew S., Alamouti, Siavash M.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): GLUCK, JEFFREY WILLIAM
• Application Number:
  US08/852,151
• Time in Patent Office: 560 Days
• Field of Search: 375/261, 375/262, 375/264, 375/265, 375/298, 375/341, 371/43.1, 371/44, 371/45, 371/43.4, 332/103
• US Class Current: 375/265
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 27/3427 in which the constellation is the n - fold Cartesian product of a single underlying two-dimensional constellation
• CPC Class Codes: H04L 7/04 Speed or phase control by synchronisation signals H04L7/0075 takes precedence

Abstract

A cellular communication system provides for trellis encoding/decoding of a 16 Star QAM signal. The system includes a transmitter circuit and a receiver circuit. The transmitter circuit has a Reed-Solomon encoder, an outer interleaver circuit for spreading burst errors, a cyclic trellis encoder, an inner interleaver circuit for reducing channel memory, a 16 Star QAM mapper and a radio frequency transmitter. The receiver circuit has a radio frequency receiver, equalization and filtering circuitry and timing and synchronization recovery circuitry. The receiver also has an inner deinterleaver, a trellis decoder, an outer deinterleaver, and a Reed-Solomon decoder.

Claims

1. A data transmitter comprising:

a trellis encoder having a plurality of defined next states each corresponding to an input and a present state, said next states cyclically assigned to the corresponding input and present states;

a signal constellation mapper coupled to said trellis encoder; and

a transmitter coupled to said signal constellation mapper.

2. A transmitter as defined in claim 1, wherein said transmitter comprises a radio frequency transmitter.

3. A transmitter as defined in claim 1, further comprising a Reed-Solomon encoder and a pilot word insertion circuit.

4. A method of transmitting data comprising the steps of:

accepting input data to be transmitted;

trellis encoding said input data by cyclically assigning a plurality of next states to a plurality of present state and input value pairs;

mapping the trellis encoded data according to a signal constellation; and

transmitting the trellis encoded, mapped data.

5. A method of transmitting data as defined in claim 4, further comprising the step of Reed-Solomon encoding said input data prior to transmission.

6. A method of transmitting data as defined in claim 5, further comprising the step of interleaving said data prior to transmission.

7. A method of transmitting data as defined in claim 6, further comprising the step of filtering said data prior to transmission.

8. A method of transmitting data as defined in claim 4, further comprising the step of encoding synchronization and differential pilot word symbols within the data before transmission.

9. A data encoder for a mobile radio data communication system, comprising:

a trellis encoder having a plurality of next states corresponding to a plurality of present states and a plurality of input values, said next states assigned to the corresponding present states and input values by dividing the next states into at least first and second subsets and assigning said first subset to a first present state and the plurality of input values, and assigning the first subset of next states to a second present state and said plurality of input values with said first subset of next states cyclically shifted from the assignment to the first present state; and

a signal constellation mapper coupled to said trellis encoder.

10. A data encoder as defined in claim 9, wherein said trellis encoder is a cyclic trellis encoder.

11. A data encoder as defined in claim 9, wherein said signal constellation mapper comprises a 16 star QAM mapper.

12. A data encoder as defined in claim 11, wherein said trellis encoder is a rate 3/4 trellis encoder.

13. The data encoder as defined in claim 11, further comprising a data interleaver.

14. A data encoder as defined in claim 9, further comprising a Reed-Solomon encoder coupled to said trellis encoder.

15. A mobile radio communication system, comprising:

a cyclic trellis encoder which receives data and trellis encodes said data, the cyclic trellis encoder having a plurality of next states corresponding to present states and data values, said plurality of next states partitioned into at least two sets and cyclically assigned to the corresponding present states and data values;

a signal constellation mapper coupled to said trellis encoder and configured to encode output data from said trellis encoder and to map said encoded data into a signal constellation;

a transmitter configured to accept the encoded and mapped data and transmit said encoded and mapped data over a communication channel;

a receiver configured to receive the transmitted data from said communication channel; and

a trellis decoder coupled to said receiver.

16. A communication system as defined in claim 15, wherein said trellis encoder is a rate 3/4 encoder.

17. A communication system as defined in claim 16, further comprising a Reed-Solomon encoder and a Reed-Solomon decoder.

18. A communication system as defined in claim 17, further comprising an outer block interleaver coupled between said Reed-Solomon encoder and said trellis encoder.

19. A communication system as defined in claim 15, wherein said transmitter comprises a radio frequency transmitter and said receiver comprises a radio frequency receiver.

20. A communication system as defined in claim 19, wherein said transmitter and said receiver are cellular communications devices.