Syndrome-based channel quality or message structure determiner

• US 5,936,972 A
• Filed: 06/18/1997
• Issued: 08/10/1999
• Est. Priority Date: 06/18/1997
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Meidan, Reuven, Ariel, Meir
• Primary Examiner(s): TU, CHRISTINE TRINH LE
• Application Number:
  US08/878,280
• Time in Patent Office: 783 Days
• Field of Search: 371/20.1, 371/5.1, 371/37.01, 371/37.07, 371/37.12, 371/67.1, 371/68.1, 371/68.2, 375/316, 375/324, 370/310, 370/333, 370/912, 370/913
• US Class Current: 714/712
• CPC Class Codes: H04L 1/20 using signal quality detector

Abstract

A syndrome-based channel quality or message structure determiner (160) uses syndrome vectors to estimate the quality of a received signal in a variable message structure communication system. A digital signal from analog-to-digital converter (150) is separated into multiple branching paths, one for each potential message structure type. In a single path, a digital demodulator (221) demodulates the digital signal to produce a demodulated received signal. A deinterleaver (222) deinterleaves the demodulated received signal, and a symbol-by-symbol detector (2231) hard-decision detects the deinterleaved signal. For each hard-decision vector, at least one syndrome calculator (2241) calculates a syndrome vector. The syndrome vector is analyzed by a syndrome error estimator (2251) having an associated syndrome pattern memory (2271). A comparator (260) analyzes error counter totals from each syndrome error estimator.

Claims

1. A syndrome-based channel quality or message structure determiner for use in a communication system receiver comprising:

a first digital demodulator, for demodulating a received digital signal to produce a first demodulated received signal;

a first symbol-by-symbol detector, coupled to the first digital demodulator, for computing a first hard-decision vector from the first demodulated received signal;

a first syndrome calculator, coupled to the first symbol-by-symbol detector, for using a first scalar parity check matrix to compute a first syndrome vector from the first hard-decision vector;

a first syndrome pattern memory for storing a first syndrome pattern and an associated first error weight; and

a first syndrome error estimator, coupled to the first syndrome calculator and the first syndrome pattern memory, for locating and removing the first syndrome pattern from the first syndrome vector and calculating a first quality estimation from the first error weight.

2. A syndrome-based channel quality or message structure determiner according to claim 1 further comprising:

a comparator, coupled to the first syndrome error estimator, for comparing the first quality estimation to a second quality estimation.

3. A syndrome-based channel quality or message structure determiner according to claim 2 wherein the second quality estimation is a predetermined error weight.

4. A syndrome-based channel quality or message structure determiner according to claim 1 further comprising:

a second syndrome calculator, coupled to the first symbol-by-symbol detector, for using a second scalar parity check matrix to compute a second syndrome vector from the first hard-decision vector;

a second syndrome pattern memory for storing a second syndrome pattern and an associated second error weight; and

a second syndrome error estimator, coupled to the second syndrome calculator and the second syndrome pattern memory, for locating and removing the second syndrome pattern from the second syndrome vector and calculating a second quality estimation from the second error weight.

5. A syndrome-based channel quality or message structure determiner according to claim 4 further comprising:

a comparator, coupled to the first syndrome error estimator and the second syndrome error estimator, for comparing the first quality estimation to the second quality estimation.

6. A syndrome-based channel quality or message structure determiner according to claim 1 further comprising:

a second digital demodulator, for demodulating the received digital signal to produce a second demodulated received signal;

a second symbol-by-symbol detector, coupled to the second digital demodulator, for computing a second hard-decision vector from the second demodulated received signal;

a second syndrome calculator, coupled to the second symbol-by-symbol detector, for using a second scalar parity check matrix to compute a second syndrome vector from the second hard-decision vector;

a second syndrome pattern memory for storing a second syndrome pattern and an associated second error weight; and

a second syndrome error estimator, coupled to the second syndrome calculator and the second syndrome pattern memory, for locating and removing the second syndrome pattern from the second syndrome vector and calculating a second quality estimation from the second error weight.

7. A syndrome-based channel quality or message structure determiner according to claim 6 further comprising:

a comparator, coupled to the first syndrome error estimator and the second syndrome error estimator, for comparing the first quality estimation to the second quality estimation.

8. A syndrome-based channel quality or message structure determiner for use in a communication system receiver comprising:

a first digital demodulator, for demodulating a received digital signal to produce a first demodulated received signal;

a first deinterleaver, coupled to the first digital demodulator, for deinterleaving the first demodulated received signal to produce a first deinterleaved signal;

a first symbol-by-symbol detector, coupled to the first deinterleaver, for computing a first hard-decision vector from the first deinterleaved signal;

a first syndrome calculator, coupled to the first symbol-by-symbol detector, for using a first scalar parity check matrix to compute a first syndrome vector from the first hard-decision vector;

a first syndrome pattern memory for storing a first syndrome pattern and an associated first error weight; and

a first syndrome error estimator, coupled to the first syndrome calculator and the first syndrome pattern memory, for locating and removing the first syndrome pattern from the first syndrome vector and calculating a first quality estimation from the first error weight.

9. A syndrome-based channel quality or message structure determiner according to claim 8 wherein the first deinterleaver also produces a second deinterleaved signal.

10. A syndrome-based channel quality or message structure determiner according to claim 9 further comprising:

a second symbol-by-symbol detector, coupled to the first deinterleaver, for computing a second hard-decision vector from the second deinterleaved signal;

a second syndrome calculator, coupled to the second symbol-by-symbol detector, for using a second scalar parity check matrix to compute a second syndrome vector from the second hard-decision vector;

a second syndrome pattern memory for storing a second syndrome pattern and an associated second error weight; and

a second syndrome error estimator, coupled to the second syndrome calculator and the second syndrome pattern memory, for locating and removing the second syndrome pattern from the second syndrome vector and calculating a second quality estimation from the second error weight.

11. A syndrome-based channel quality or message structure determiner according to claim 10 further comprising:

a comparator, coupled to the first syndrome error estimator and the second syndrome error estimator, for comparing the first quality estimation to the second quality estimation.

12. A cellular radiotelephone comprising:

a syndrome-based channel quality or message structure determiner including;

a digital demodulator, for demodulating a received digital signal to produce a demodulated received signal;

a symbol-by-symbol detector, coupled to the digital demodulator, for computing a hard-decision vector from the demodulated received signal;

a syndrome calculator, coupled to the symbol-by-symbol detector, for using a scalar parity check matrix to compute a syndrome vector from the hard-decision vector;

a syndrome pattern memory for storing a syndrome pattern and an associated error weight; and

a syndrome error estimator, coupled to the syndrome calculator and the syndrome pattern memory, for locating and removing the syndrome pattern from the syndrome vector and calculating a quality estimation from the error weight.

13. A cellular radiotelephone according to claim 12 wherein the syndrome-based channel quality or message structure determiner further comprises:

a comparator, coupled to the syndrome error estimator, for comparing the quality estimation to a predetermined error weight.

14. A method for determining a transmitted signal'"'"'s quality or message structure comprising the steps of:

demodulating a received digital signal to produce a first demodulated received signal;

computing a first hard-decision vector from the first demodulated received signal;

using a first scalar parity check matrix to compute a first syndrome vector from the first hard-decision vector; and

locating and removing a first syndrome pattern from the first syndrome vector and calculating a first quality estimation from a first error weight.

15. A method for determining a transmitted signal'"'"'s quality or message structure according to claim 14 further comprising the step of:

comparing the first quality estimation to a second quality estimation.

16. A method for determining a transmitted signal'"'"'s quality or message structure according to claim 14 further comprising the steps of:

using a second scalar parity check matrix to compute a second syndrome vector from the first hard-decision vector; and

locating and removing a second syndrome pattern from the second syndrome vector and calculating a second quality estimation from a second error weight.

17. A method for determining a transmitted signal'"'"'s quality or message structure according to claim 16 further comprising the steps of:

comparing the first quality estimation to the second quality estimation.