Multiple user CDMA basestation modem

• US 6,333,926 B1
• Filed: 08/11/1998
• Issued: 12/25/2001
• Est. Priority Date: 08/11/1998
• Status: Expired due to Term

• Current Assignee: Ericsson AB (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Van Heeswyk, Frank Martin, Newson, Paul
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): Pham, Brenda H.
• Application Number:
  US09/132,466
• Time in Patent Office: 1,232 Days
• Field of Search: 375/130, 375/141, 375/144, 375/146, 375/148, 370/320, 370/334, 370/335, 370/342, 370/441, 370/329
• US Class Current: 370/335
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 7/2628 using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA] H04B7/2618 takes precedence

Abstract

A CDMA modem with dynamically allocatable demodulation and modulation, encoding/interleaving and decoding/de-interleaving for multiple resources users is provided. Each component is individually configurable to function as any one of various physical layer channel types for one or more different CDMA standards.

Claims

1. A CDMA transmitter signal processing apparatus comprising:

an encoder/interleaver bank having a plurality of encoder/interleavers each having an input and an output;

a modulator bank comprising a plurality of modulators each having an input and an output, wherein each modulator is dynamically configurable to service signals adhering to one of several different standards and wherein each modulator comprises;

a first modulator path containing BPSK modulation functions and functions for a first half of a QPSK modulator;

a second modulator path containing functions for a second half of a QPSK modulator; and

input routing circuitry switchable between a first state and a second state, which when in said first state routes entire received bit streams to the first modulator path thereby causing the configurable modulator to function in a BPSK mode, and when in said second state routes the received bit streams to said first path and to said second path thereby causing the configurable modulator to function in a QPSK mode;

a modulator switch for connecting any encoder/interleaver output to any one or more modulator inputs;

a plurality of summers each having a respective plurality of inputs and an output; and

an output switch for connecting any modulator outputs to any summer input.

2. An apparatus according to claim 1 wherein said input routing circuitry when in said second state routes every odd bit to said second path and routes every even bit to said first path.

3. An apparatus according to claim 2 wherein:

when in said first state, the modulator includes Walsh, Gain, and PNi and PNq spreading functions which operate on said first path to produce I and Q outputs;

when in said second state, the modulator includes Walsh, Gain, and power control functions in each of said first and second paths, and includes PNi and PNq spreading functions which perform PNi spreading on each of said first and second paths and PNq spreading on each of said first and second paths, and combiners which combine a PNi spread output of the first path with a PNq spread output of the second path and which combine a PNi spread output of the second path with a PNq spread output of the first path.

4. A CDMA transmitter signal processing apparatus comprising:

an encoder/interleaver bank having a plurality of encoder/interleavers each having an input and an output, wherein each encoder/interleaver is dynamically configurable to service signals adhering to one of several different standards and further comprising a data interface for connecting any one of the plurality of data inputs to a respective input of one of the encoder/interleavers and wherein each configurable encoder/interleaver comprises;

an add reserved bits block;

an add CRC block;

an add encoder tail block;

a convolutional encoder block;

a symbol repetition block;

a symbol deletion block;

a block interleaver block; and

a long code modulation block;

wherein each block of the encoder/interleaver is individually configurable and bypassable;

a modulator bank comprising a plurality of modulators each having an input and an output;

a modulator switch for connecting any encoder/interleaver output to any one or more modulator inputs;

a plurality of summers each having a respective plurality of inputs and an output; and

an output switch for connecting any modulator outputs to any summer input.

5. An apparatus according to claim 4 wherein each block in each encoder/interleaver is individually configurable and bypassable so as to function as an encoder/interleaver for any IS-95 physical channel layer type and as an encoder/interleaver for any IS-95 3G physical channel layer type.

6. A CDMA receiver apparatus comprising:

a plurality of fingers each having an input and an output;

a switch for switching each of a plurality of receive inputs to any one or more finger inputs;

a plurality of summers each having a respective plurality of inputs and an output;

a weighting and thresholding circuitry connected to the outputs of the fingers and having thresholded outputs, the circuitry adapted to perform weighting and thresholding of outputs of the fingers; and

an output switch adapted to connect any thresholded output to any summer input.

7. An apparatus according to claim 6 further comprising:

a decoder/de-interleaver bank having a plurality of decoder/de-interleavers each having an input and an output;

a signal router for connecting any summer output to any decoder/de-interleaver input.

8. An apparatus according to claim 7 wherein each decoder/de-interleaver is dynamically configurable to function according to any one of a plurality of different standards.

9. An apparatus according to claim 6 wherein each finger is dynamically configurable to function according to any one of a plurality of different standards.

10. An apparatus according to claim 6 further comprising a control block which reconfigures the entire apparatus once per frame.

11. A CDMA receiver apparatus comprising:

a plurality of fingers each having an input and an output, wherein each finger comprises three demodulators connected together in a delay locked loop, each demodulator comprising;

a plurality of configurable functional blocks each configurable to function for at least two different standards;

for each said standard, a respective plurality of functional blocks permanently configured to function for the standard; and

switching means for switching the demodulator between different standards by configuring each configurable block to that standard, by switching in each permanently configured block for that standard, and by switching out each permanently configured block for any other standard;

a switch for switching each of a plurality of receive inputs to any one or more finger inputs;

a plurality of summers each having a respective plurality of inputs and an output;

a weighting and thresholding circuitry connected to the outputs of the fingers and having thresholded outputs, the circuitry adapted to perform weighting and thresholding of outputs of the fingers; and

an output switch adapted to connect any thresholded output to any summer input.

12. An apparatus according to claim 11 wherein:

said configurable functional blocks comprise a PN despreader block and a signal routing block;

said permanently configured blocks comprise;

a) a first channel connectable to receive an output of the PN despreader block and comprising demodulation functions for a first standard;

b) a second channel also connectable to receive said output of the PN despreader block and comprising demodulation functions for a second type;

the first and second channels each having outputs connected to the signal routing block.

13. An apparatus according to claim 12 wherein the first channel comprises integrate, fast Hadamard transform and compute metrics blocks, and the second channel comprises carrier phase recovery and integrate blocks.

15. An apparatus according to claim 11 wherein each block of each decoder/de-interleaver is individually configurable or bypassable so as to function as an decoder/de-interleaver for any IS-95 physical channel layer type and as an decoder/de-interleaver for any IS-95 3G physical channel layer type.

14. A CDMA receiver apparatus comprising:

a plurality of fingers each having an input and an output;

a switch for switching each of a plurality of receive inputs to any one or more finger inputs;

a plurality of summers each having a respective plurality of inputs and an output;

a weighting and thresholding circuitry connected to the outputs of the fingers and having thresholded outputs, the circuitry adapted to perform weighting and thresholding of outputs of the fingers;

an output switch adapted to connect any thresholded output to any summer input;

a decoder/de-interleaver bank having a plurality of decoder/de-interleavers each having an input and an output; and

a signal router for connecting any summer output to any decoder/de-interleaver input;

wherein

each decoder/de-interleaver comprises;

a long code demodulation block;

a block de-interleaver block;

a symbol integration block;

a convolutional decoder block;

a remove encoder tail block;

a remove and check CRC block; and

a remove reserved bits block,

wherein each block of the decoder/de-interleaver is individually configurable or bypassable.