Self-selective multi-rate transmitter

• US 6,370,202 B1
• Filed: 11/23/1998
• Issued: 04/09/2002
• Est. Priority Date: 11/23/1998
• Status: Expired due to Term

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Wolcott, Theodore J.
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): PHU, PHUONG M
• Application Number:
  US09/197,902
• Time in Patent Office: 1,233 Days
• Field of Search: 375/265, 375/295, 375/130, 375/140, 375/141, 375/146, 375/259, 714/756, 370/538, 370/466
• US Class Current: 375/295
• CPC Class Codes: H03M 13/15 Cyclic codes, i.e. cyclic shifts of codewords produce other codewords, e.g. codes defined by a generator polynomial, Bose-Chaudhuri-Hocquenghem [BCH] codes H03M13/17 takes precedence
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/256 with trellis coding, e.g. with convolutional codes and TCM
• CPC Class Codes: H03M 13/2707 Simple row-column interleaver, i.e. pure block interleaving
• CPC Class Codes: H03M 13/2732 Convolutional interleaver; Interleavers using shift-registers or delay lines like, e.g. Ramsey type interleaver
• CPC Class Codes: H03M 13/2936 comprising an outer Reed-Solomon code and an inner convolutional code
• CPC Class Codes: H03M 13/6508 Flexibility, adaptability, parametrability and configurability of the implementation
• CPC Class Codes: H03M 13/6561 Parallelized implementations
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0043 Realisations of complexity reduction techniques, e.g. use of look-up tables
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/006 Trellis-coded modulation
• CPC Class Codes: H04L 1/0065 Serial concatenated codes
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27

Abstract

An architecture for a self-selective multi-rate transmitter that processes variable input rate data using a plurality of single input, multiple output interleavers. The transmitter, using a multitude of modulation formats, transmits the data at a constant symbol rate without a priori knowledge of the input rate. The transmitter employs a modulator that automatically selects between a multitude of signal constellations, depending on the rate of the source data to be transmitted. The modulator transmits data from various sources, each with an independent data rate. The modulator performs data formatting, forward error correction encoding, modulation onto an intermediate frequency, frequency conversion to a transmit radio frequency, and amplification with automatic gain control.

Claims

1. A self-selective multi-rate transmitter, comprising:

first and second single input, multiple output interleavers that each receive input data having a variable data rate and generate a desired number of parallel output data streams depending on the data rate of the input data and without a priori knowledge of the data rate of the input data, that correspond to uncoded k-bit symbols of an M-ary signal constellation; and

a modulator coupled to outputs of the interleavers that processes the uncoded k-bit symbols to generate the M-ary signal constellation that is a function of the number of parallel output data streams generated by the interleavers.

2. The transmitter recited in claim 1 wherein the modulator comprises:

a forward error correction circuit coupled to outputs of the interleavers that generate n parallel channels of coded data, one parallel channel for each bit in the required M-ary signal constellation;

a vector modulator coupled to outputs forward error correction circuit;

an upconverter coupled to an output of the vector modulator; and

an amplifier coupled to an output of the upconverter.

3. The transmitter recited in claim 1 wherein the modulator comprises:

a forward error correction circuit coupled to outputs of the interleavers that generate n parallel channels of coded data, one parallel channel for each bit in the required M-ary signal constellation;

a modulated array transmitter coupled to outputs forward error correction circuit; and

an upconverter coupled to an output of the modulated array transmitter.

4. The transmitter recited in claim 1 wherein the amplifier comprises a traveling wave tube amplifier.

5. The transmitter recited in claim 1 wherein the amplifier comprises a solid state power amplifier.

6. The transmitter recited in claim 1 wherein the single input, multiple output interleaver comprises:

an input switch for receiving the variable rate input data;

a stop word generator coupled to the input switch for selectively adding a stop word to the data; and

a plurality of registers that are selectively coupled together by way of a plurality of output switches.

7. The transmitter recited in claim 1 wherein the forward error correction circuit comprises:

a plurality of Reed-Solomon encoders having a plurality of inputs coupled to the outputs of the interleavers;

a plurality of delay circuits coupled to outputs of all but the last Reed-Solomon encoder; and

drives a shift register and adder circuit, which performs convolutional encoding, coupled to the last Reed-Solomon encoder.

8. The transmitter recited in claim 2 wherein the amplifier comprises a traveling wave tube amplifier.

9. The transmitter recited in claim 2 wherein the amplifier comprises a solid state power amplifier.

10. The transmitter recited in claim 2 wherein the single input, multiple output interleaver comprises:

an input switch for receiving the variable rate input data;

a stop word generator coupled to the input switch for selectively adding a stop word to the data; and

a plurality of registers that are selectively coupled together by way of a plurality of output switches.

11. The transmitter recited in claim 2 wherein the forward error correction circuit comprises:

a plurality of Reed-Solomon encoders having a plurality of inputs coupled to the outputs of the interleavers;

a plurality of delay circuits coupled to outputs of all but the last Reed-Solomon encoder; and

drives a shift register and adder circuit, which performs convolutional encoding, coupled to the last Reed-Solomon encoder.

12. The transmitter recited in claim 3 wherein the amplifier comprises a traveling wave tube amplifier.

13. The transmitter recited in claim 3 wherein the amplifier comprises a solid state power amplifier.

14. The transmitter recited in claim 3 wherein the single input, multiple output interleaver comprises:

an input switch for receiving the variable rate input data;

a stop word generator coupled to the input switch for selectively adding a stop word to the data; and

a plurality of registers that are selectively coupled together by way of a plurality of output switches.

15. The transmitter recited in claim 3 wherein the forward error correction circuit comprises:

a plurality of Reed-Solomon encoders having a plurality of inputs coupled to the outputs of the interleavers;

a plurality of delay circuits coupled to outputs of all but the last Reed-Solomon encoder; and

drives a shift register and adder circuit, which performs convolutional encoding, coupled to the last Reed-Solomon encoder.