Spread-spectrum communications utilizing variable throughput reduction

• US 6,289,039 B1
• Filed: 06/14/2000
• Issued: 09/11/2001
• Est. Priority Date: 06/14/2000
• Status: Expired due to Term

• Current Assignee: Stormborn Technologies LLC (IP Edge LLC)
• Original Assignee: Linex Technologies, Inc.
• Inventors: Garodnick, Joseph
• Primary Examiner(s): VO, DON NGUYEN
• Application Number:
  US09/594,440
• Time in Patent Office: 454 Days
• Field of Search: 375/140, 375/141, 375/142, 375/143, 375/144, 375/148, 375/150, 375/151, 375/152, 375/153, 370/320, 370/335, 370/342, 370/441
• US Class Current: 375/143
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 2201/70703 using multiple or variable rates
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04J 13/004 Orthogonal
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/004 by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/02 by diversity reception
• CPC Class Codes: H04L 2001/0096 Channel splitting in point-to-point links
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A spread-spectrum system having a transmitted data rate determined by an error rate syndrome at a spread-spectrum receiver. A demultiplexer demultiplexes input data into a plurality of data channels. A plurality of FEC encoders FEC encodes the plurality of data channels, as a plurality of FEC encoded channels. A plurality of spread-spectrum processors spread-spectrum processes the plurality of FEC encoded channels as a plurality of spread-spectrum channels. The plurality of spread-spectrum channels preferably uses a plurality of orthogonal or quasi-orthogonal chip-sequence signals to define a particular spread-spectrum channel. A combiner combines the plurality of spread-spectrum channels as a code-division-multiplexed signal. At a receiver, a plurality of spread-spectrum despreaders despreads the code-division-multiplexed signal into a plurality of despread channels. A multiplicity of adders is electronically controlled by an adder-control signal. The multiplicity of adders adds several of the despread channels to generate a multiplicity of added channels. A multiplicity of FEC decoders generates a syndrome signal from an error rate of the multiplicity of added channels. A command processor determines, from the syndrome signal, a desired-data rate, and generates a data-rate command signal having the desired-data rate for the spread-spectrum transmitter. The command processor also generates the adder-control signal for adding together a number of despread channels of the plurality of despread channels, and generates a multiplexer signal having a number of decoded channels to multiplex together. The multiplexer multiplexes the multiplicity of decoded channels to generate an estimate of the input data.

Claims

1. A spread-spectrum system comprising:

a demultiplexer for demultiplexing input data into a plurality of data channels;

a plurality of forward-error-correction encoders and interleavers, coupled to said demultiplexer, for FEC encoding and interleaving the plurality of data channels as a plurality of FEC encoded and interleaved channels, respectively;

a plurality of spread-spectrum processors, coupled to said plurality of FEC encoders and interleavers, for spread-spectrum processing the plurality of FEC encoded and interleaved channels as a plurality of spread-spectrum channels, employing a plurality of chip-sequence signals;

a combiner coupled to said plurality of spread-spectrum processors, for combining the plurality of spread-spectrum channels as a code-division-multiplexed signal;

a modulator for transmitting the code-division-multiplexed signal having the plurality of spread-spectrum channels, over a communications channel;

a demodulator for translating the code-division-multiplexed signal to a processing frequency;

a plurality of spread-spectrum despreaders for despreading the code-division-multiplexed signal into a plurality of despread channels, respectively;

a multiplicity of adders, electronically controlled by an adder-control signal, for adding at least two despread channels to generate a multiplicity of added channels;

a multiplicity of FEC decoder and de-interleavers, coupled to said multiplicity of adders, for generating a syndrome signal from an error rate of the multiplicity of added channels, and for FEC decoding and de-interleaving the multiplicity of added channels, and a multiplicity of decoded channels;

a command processor, responsive the syndrome signal, for determining a desired-data rate, for generating a data-rate command signal having the desired data rate, for generating the adder-control signal for adding together a number of despread channels of the plurality of despread channels, and for generating a multiplexer signal having a number of decoded channels to multiplex together; and

a multiplexer, coupled to said plurality of FEC decoders and de-interleavers and said command processor, for multiplexing the multiplicity of decoded channels and an estimate of the input data.

2. The spread-spectrum system as set forth in claim 1 further including a buffer, coupled before the demultiplexer, for storing input data prior to demultiplexing the input data.

3. The spread-spectrum system as set forth in claim 1, with said plurality of spreaders including:

a chip-sequence generator for generating the plurality of orthogonal chip-sequence signals; and

a plurality of product devices, coupled to said chip-sequence generator, for spread-spectrum processing the plurality of encoded channels as the plurality of spread-spectrum channels.

4. The spread-spectrum system as set forth in claim 1, with said plurality of spreaders including:

a chip-sequence generator for generating the plurality of quasi-orthogonal chip-sequence signals; and

a plurality of product devices, coupled to said chip-sequence generator, for spread-spectrum processing the plurality of encoded channels as the plurality of spread-spectrum channels.

5. The spread-spectrum system as set forth in claim 1, with said plurality of despreaders further including:

a chip-sequence generator for generating a replica of the plurality of chip-sequence signals; and

a plurality of product devices, coupled to said chip-sequence generator, for despreading the code-division-multiplexed signal as a plurality of despread channels.

6. The spread-spectrum system as set forth in claim 1, with said plurality of despreaders including a plurality a matched filters, having a plurality of impulse responses matched to the plurality of chip-sequence signals, respectively.

7. The spread-spectrum system as set forth in claim 1, with said plurality of despreaders including a plurality a surface acoustic wave (SAW) devices, having a plurality of impulse responses matched to the plurality of chip-sequence signals, respectively.

8. A spread-spectrum system comprising:

demultiplexer means for demultiplexing input data into a plurality of data channels;

encoder means for FEC encoding and interleaving the plurality of data channels as a plurality of FEC encoded and interleaved channels, respectively;

spreader means for spread-spectrum processing the plurality of FEC encoded and interleaved channels as a plurality of spread-spectrum channels, having a plurality of chip-sequence signals;

combiner means for combining the plurality of spread-spectrum channels as a code-division-multiplexed signal;

modulator means for transmitting the code-division-multiplexed signal having the plurality of spread-spectrum channels, over a communications channel;

demodulator means for translating the code-division-multiplexed signal to a processing frequency;

despreader means for despreading the code-division-multiplexed signal into a plurality of despread channels, respectively;

adder means, electronically controlled by an adder-control signal, for adding at least two despread channels to generate a multiplicity of added channels;

decoder means for generating a syndrome signal from an error rate of the multiplicity of added channels, and for FEC decoding and de-interleaving the multiplicity of added channels and a multiplicity of decoded channels;

command means, responsive the syndrome signal, for determining a desired-data rate, for generating a data-rate command signal having the desired data rate, for generating the adder-control signal for adding together a number of despread channels of the plurality of despread channels, and for generating a multiplexer signal having a number of decoded channels to multiplex together; and

multiplexer means for multiplexing the multiplicity of decoded channels and an estimate of the input data.

9. The spread-spectrum system as set forth in claim 8 further including a buffer, coupled before said demultiplexer means, for storing input data prior to demultiplexing the input data.

10. The spread-spectrum system as set forth in claim 8, with said spreader means including:

a chip-sequence generator for generating the plurality of orthogonal chip-sequence signals; and

a plurality of product devices, coupled to said chip-sequence generator, for spread-spectrum processing the plurality of encoded channels as the plurality of spread-spectrum channels.

11. The spread-spectrum system as set forth in claim 8, with said spreader means including:

a chip-sequence generator for generating the plurality of quasi-orthogonal chip-sequence signals; and

a plurality of product devices, coupled to said chip-sequence generator, for spread-spectrum processing the plurality of encoded channels as the plurality of spread-spectrum channels.

12. The spread-spectrum system as set forth in claim 8, with said despreader means further including:

a chip-sequence generator for generating a replica of the plurality of chip-sequence signals; and

a plurality of product devices, coupled to said chip-sequence generator, for despreading the code-division-multiplexed signal as a plurality of despread channels.

13. The spread-spectrum system as set forth in claim 8, with said despreader means including a plurality a matched filters, having a plurality of impulse responses matched to the plurality of chip-sequence signals, respectively.

14. The spread-spectrum system as set forth in claim 8, with said despreader means including a plurality a surface acoustic wave (SAW) devices, having a plurality of impulse responses matched to the plurality of chip-sequence signals.

15. A spread-spectrum method comprising the steps of:

demultiplexing input data into a plurality of data channels;

FEC encoding and interleaving the plurality of data channels as a plurality of FEC encoded and interleaved channels respectively;

spread-spectrum processing the plurality of FEC encoded and interleaved channels as a plurality of spread-spectrum channels, employing a plurality of chip-sequence signals;

combining the plurality of spread-spectrum channels as a code-division-multiplexed signal;

transmitting the code-division-multiplexed signal having the plurality of spread-spectrum channels, over a communications channel;

translating the code-division-multiplexed signal to a processing frequency;

despreading the code-division-multiplexed signal into a plurality of despread channels, respectively;

adding at least two despread channels to generate a multiplicity of added channels;

generating a syndrome signal from an error rate of the multiplicity of added channels;

FEC decoding and de-interleaving the multiplicity of added channels, and a multiplicity of decoded channels;

determining, in response to the syndrome signal, a desired-data rate;

generating a data-rate command signal having the desired data rate;

generating, in response to the syndrome signal, the adder-control signal for adding together a number of despread channels of the plurality of despread channels;

generating, in response to the syndrome signal, a multiplexer signal having a number of decoded channels to multiplex together;

multiplexing the multiplicity of decoded channels and an estimate of the input data.

16. The spread-spectrum methodsystem as set forth in claim 15 further including, before the step of demultiplexing, the step of storing input data prior to demultiplexing the input data.

17. The spread-spectrum method as set forth in claim 15, with the step of spread-spectrum processing including the steps of:

generating the plurality of orthogonal chip-sequence signals; and

spread-spectrum processing the plurality of encoded channels as the plurality of spread-spectrum channels.

18. The spread-spectrum method as set forth in claim 15, with the step of spread-spectrum processing including the steps of:

generating the plurality of quasi-orthogonal chip-sequence signals; and

spread-spectrum processing the plurality of encoded channels as the plurality of spread-spectrum channels.

19. The spread-spectrum method as set forth in claim 15, with the step of despreading further including the steps of:

generating a replica of the plurality of chip-sequence signals; and

despreading the code-division-multiplexed signal as a plurality of despread channels.

20. The spread-spectrum method as set forth in claim 15, with the step of despreading including the step of filtering, with a plurality of impulse responses matched to the plurality of chip-sequence signals, respectively.