Method and apparatus for determining data rate of transmitted variable rate data in a communications receiver

Claim 2

In a receiver of a variable-rate communication system, a method for determining a data rate of a received signal comprising the steps of: decoding and re-encoding at a first data rate said received signal to produce a first received signal prediction and to produce a first quality indication; comparing said first received signal prediction to said received signal and counting a first number of errors, wherein an error occurs when said received signal does not match said first received signal prediction, and wherein said first number of errors and said first quality indication define a first error metric; reducing said received signal to produce a second received signal representing a second data rate; decoding and re-encoding at said second data rate said second received signal to produce a second received signal prediction and to produce a second quality indication; comparing said second received signal prediction to said second received signal and counting a second number of errors, wherein an error occurs when said second received signal does not match said second received signal prediction, and wherein said second number of errors and said second quality indication define a second error metric; and predicting said data rate of said received signal based on a comparison of each of said error metrics.

Claim 3

The method of claim 1 further comprising the steps of: reducing said received signal to produce a third received signal representing a third data rate; decoding and re-encoding at said third data rate said third received signal to produce a third received signal prediction and to produce a third quality indication; and comparing said third received signal prediction to said third received signal and counting a third number of errors, wherein an error occurs when said third received signal does not match said third received signal prediction, and wherein said third number of errors and said third quality indication define a third error metric.

Claim 4

The method of claim 2 further comprising the steps of: reducing said received signal to produce a fourth received signal representing a fourth data rate; decoding and re-encoding at said fourth data rate said fourth received signal to produce a fourth received signal prediction and to produce a fourth quality indication; and comparing said fourth received signal prediction to said fourth received signal and counting a fourth number of errors, wherein an error occurs when said fourth received signal does not match said fourth received signal prediction, and wherein said fourth number of errors and said fourth quality indication define a fourth error metric.

Claim 5

The method of claim 1 wherein said step of reducing comprises the steps of: dividing in time said received signal to produce an early received signal and a late received signal; and summing said early received signal and said late received signal to produce said second received signal.

Claim 6

The method of claim 1 wherein said received signal is divided in time into a set of segments and wherein said step of reducing comprises the step of selecting a subset of said set of segments of said received signal to produce said second received signal.

Claim 7

The method of claim 2 wherein said step of reducing to produce said third signal comprises the steps of: dividing in time said second received signal to produce an early second received signal and a late second received signal; and summing said early second received signal and said late second received signal to produce said third received signal.

Claim 8

The method of claim 2 wherein said second received signal is divided in time into a set of segments and wherein said step of reducing to produce said third signal comprises the step of selecting a subset of said set of segments of said second received signal to produce said third received signal.

Claim 9

The method of claim 1 wherein said first quality indication is a Cyclic Redundancy Check result.

Claim 10

The method of claim 3 wherein: said first data rate corresponds to full rate communication; said second data rate corresponds to half rate communication; said third data rate corresponds to quarter rate communication; and said fourth data rate corresponds to eighth rate communication.

Claim 11

The method of claim 9 wherein said first quality indication, said second quality indication, said third quality indication, and said fourth quality indication are each a single bit binary quality indication wherein a "1" indicates a high probability that said data rate of said received signal is the data rate corresponding to said quality indication and a "0" indicates said data rate of said received signal is not the data rate corresponding to said quality indication.

Claim 12

The method of claim 10, wherein said step of predicting said data rate of said received signal comprises the steps of: predicting said a first data rate if (said first quality indication=1 AND said second quality indication=1) is true and (said first number of errors≦said second number of errors+T 1 ) is true, or if (said first quality indication=1 AND said second quality indication=1) is false and (said first quality indication=1 AND said first number of errors≦T 2 ) is true; predicting a half-rate indication if (said first quality indication=1 AND said second quality indication=1) is true and (said first number of errors≦said second number of errors+T 1 ) is false, or if (said first quality indication =1 AND said second quality indication=1) is false and (said first quality indication=1 AND said first number of errors≦T 2 ) is false and (said second quality indication=1 AND said second number of errors≦T 3 ) is true and (said fourth quality indication=1 AND (said third quality indication=0 OR said fourth number of errors≦said third number of errors)) is true and (said second number of errors≦said fourth number of errors+T 4 ) is true, or if (said first quality indication=1 AND said second quality indication=1) is false and (said first quality indication=1 AND said first number of errors≦T 2 ) is false and (said second quality indication=1 AND said second number of errors≦T 3 ) is true and (said fourth quality indication=1 AND (said third quality indication=0 OR said fourth number of errors≦said third number of errors)) is false and (said third quality indication=1) is true and (said second number of errors≦said third number of errors+T 5 ) is true, or if (said first quality indication=1 AND said second quality indication=1) is false and (said first quality indication=1 AND said first number of errors≦T 2 ) is false and (said second quality indication=1 AND said second number of errors≦T 3 ) is true and (said fourth quality indication=1 AND (said third quality indication=0 OR said fourth number of errors≦said third number of errors)) is false and (said third quality indication=1) is false; predicting a quarter-rate indication if (said first quality indication=1 AND said second quality indication=1) is false and (said first quality indication=1 AND said first number of errors≦T 2 ) is false and (said second quality indication=1 AND said second number of errors≦T 3 ) is true and (said fourth quality indication=1 AND (said third quality indication=0 OR said fourth number of errors≦said third number of errors)) is false and (said third quality indication=1) is true and (said second number of errors≦said third number of errors+T 5 ) is false, or if (said first quality indication=1 AND said second quality indication=1) is false and (said first quality indication=1 AND said first number of errors≦T 2 ) is false and (said second quality indication=1 AND said second number of errors≦T 3 ) is false and (said third quality indication=1 AND said fourth quality indication=1) is true and (said fourth number of errors<said third number of errors AND said fourth number of errors≦T 6 ) is false and (said third number of errors<said fourth number of errors AND said third number of errors≦T 7 ) is true, or if (said first quality indication=1 AND said second quality indication=1) is false and (said first quality indication=1 AND said first number of errors≦T 2 ) is false and (said second quality indication=1 AND said second number of errors≦T 3 ) is false and (said third quality indication=1 AND said fourth quality indication=1) is false and (said third quality indication=1 AND said third number of errors≦T 8 ) is true; and predicting an eighth-rate indication if (said first quality indication=1 AND said second quality indication=1) is false and (said first quality indication=1 AND said first number of errors≦T 2 ) is false and (said second quality indication=1 AND said second number of errors≦T 3 ) is true and (said fourth quality indication=1 AND (said third quality indication=0 OR said fourth number of errors≦said third number of errors)) is true and (said second number of errors≦said fourth number of errors+T 4 ) is false, or if (said first quality indication=1 AND said second quality indication=1) is false and (said first quality indication=1 AND said first number of errors≦T 2 ) is false and (said second quality indication=1 AND said second number of errors≦T 3 ) is false and (said third quality indication=1 AND said fourth quality indication=1) is true and (said fourth number of errors≦said third number of errors AND said fourth number of errors≦T 6 ) is true, or if (said first quality indication=1 AND said second quality indication=1) is false and (said first quality indication=1 AND said first number of errors≦T 2 ) is false and (said second quality indication=1 AND said second number of errors≦T 3 ) is false and (said third quality indication=1 AND said fourth quality indication=1) is false and (said third quality indication=1 AND said third number of errors≦T 8 ) is false and (said fourth quality indication=1 AND said fourth number of errors≦T 9 ) is true; wherein T 1 , T 2 , T 3 , T 4 , T 5 , T 6 , T 7 , T 8 , and T 9 , are fixed constants.

Claim 13

The method of claim 11 wherein T 10 is a fixed constant, further comprising the step of: producing an unrecoverable error indication if (said first quality indication=1 AND said second quality indication=1 ) is false and (said first quality indication=1 AND said first number of errors≦T 2 ) is false and (said second quality indication=1 AND said second number of errors≦T 3 ) is false and (said third quality indication=1 AND said fourth quality indication=1) is true and (said fourth number of errors≦said third number of errors AND said fourth number of errors≦T 6 ) is false and (said third number of errors<said fourth number of errors AND said third number of errors≦T 7 ) is false, or if (said first quality indication=1 AND said second quality indication=1) is false and (said first quality indication 1 AND said first number of errors≦T 2 ) is false and (said second quality indication=1 AND said second number of errors≦T 3 ) is false and (said third quality indication=1AND said fourth quality indication=1) is false and (said third quality indication=1 AND said third number of errors≦T 8 ) is false and (said fourth quality indication=1 AND said fourth number of errors≦T 9 ) is false and (said first number of errors≦T 10 ) is false.

Claim 14

The method of claim 12, further comprising the step of: producing a full-rate-with-bit-errors indication if (said first quality indication=1 AND said second quality indication=1) is false and (said first quality indication=1 AND said first number of errors≦T 2 ) is false and (said second quality indication=1 AND said second number of errors≦T 3 ) is false and (said third quality indication=1AND said fourth quality indication=1) is false and (said third quality indication=1 AND said third number of errors≦T 8 ) is false and (said fourth quality indication=1 AND said fourth number of errors≦T 9 ) is false and (said first number of errors≦T 10 ) is true.

Claim 15

The method of claim 11 wherein said full rate communication is 9,600 bits per second.

Claim 16

The method of claim 13 wherein said full rate communication is 9,600 bits per second.

Claim 17

The method of claim 13 where in: T 1 has a value equal to 15; T 2 has a value equal to 77; T 3 has a value equal to 60; T 4 has a value equal to 10; T 5 has a value equal to 10; T 6 has a value equal to 64; T 7 has a value equal to 60; T 8 has a value equal to 60; T 9 has a value equal to 64; and T 10 has a value equal to 71.

Claim 18

The method of claim 13 wherein: T 1 has a value equal to 15; T 2 has a value equal to 110; T 3 has a value equal to 84; T 4 has a value equal to 10; T 5 has a value equal to 10; T 6 has a value equal to 96; T 7 has a value equal to 76; T 8 has a value equal to 76; T 9 has a value equal to 96; and T 10 has a value equal to 78.

Claim 19

The method of claim 13 wherein: T 1 is about to 4% of the number of symbols in a frame; T 2 is about to 20% of the number of symbols in a frame; T 3 is about to 16% of the number of symbols in a frame; T 4 is about to 3% of the number of symbols in a frame; T 4 is about to 3% of the number of symbols in a frame; T 6 is about to 17% of the number of symbols in a frame; T 7 is about to 16% of the number of symbols in a frame; T 8 is about to 16% of the number of symbols in a frame; T 9 is about to 17% of the number of symbols in a frame; and T 10 is about to 19% of the number of symbols in a frame.

Claim 20

The method of claim 13 wherein: T 1 is about to 4% of the number of symbols in a frame; T 2 is about to 29% of the number of symbols in a frame; T 3 is about to 22% of the number of symbols in a frame; T 4 is about to 3% of the number of symbols in a frame; T 5 is about to 3% of the number of symbols in a frame; T 6 is about to 25% of the number of symbols in a frame; T 7 is about to 20% of the number of symbols in a frame; T 8 is about to 20% of the number of symbols in a frame; T 9 is about to 25% of the number of symbols in a frame; and T 10 is about to 20% of the number of symbols in a frame.

Claim 21

In a receiver of a variable-rate communication system, a method for decoding a received signal at an unknown data rate comprising the steps of: decoding at a first data rate said received signal to produce a first decoded received signal and to produce a first quality indication; re-encoding at said first data rate said first decoded received signal to produce a first received signal prediction; comparing said first received signal prediction to said received signal and counting a first number of errors, wherein an error occurs when said received signal does not match said first received signal prediction, and wherein said first number of errors and said first quality indication define a first error metric; decoding at a second data rate said received signal to produce a second decoded received signal and to produce a second quality indication; re-encoding at said second data rate said second decoded received signal to produce a second received signal prediction; comparing said second received signal prediction to said received signal and counting a second number of errors, wherein an error occurs when said received signal does not match said second received signal prediction, and wherein said second number of errors and said second quality indication define a second error metric; predicting said unknown data rate based on a comparison of each of said error metrics; and using said decoded received signal corresponding to said predicted unknown data rate as the bases of further processing.

Claim 22

In a receiver of a variable-rate communication system, a method for decoding a received signal at an unknown data rate comprising the steps of: decoding at a first data rate said received signal to produce a first decoded received signal and to produce a first quality indication; re-encoding at said first data rate said first decoded received signal to produce a first received signal prediction; comparing said first received signal prediction to said received signal and counting a first number of errors, wherein an error occurs when said received signal does not match said first received signal prediction, and wherein said first number of errors and said first quality indication define a first error metric; decoding at a second data rate said received signal to produce a second decoded received signal and to produce a second quality indication; re-encoding at said second data rate said second decoded received signal to produce a second received signal prediction; comparing said second received signal prediction to said received signal and counting a second number of errors, wherein an error occurs when said received signal does not match said second received signal prediction, and wherein said second number of errors and said second quality indication define a second error metric; predicting said unknown data rate based on a comparison of each of said error metrics; and using said decoded received signal corresponding to said predicted unknown data rate as the bases of further processing.

Claim 23

In a receiver of a variable-rate communication system, a method for decoding a received signal at an unknown data rate comprising the steps of: decoding at a first data rate said received signal to produce a first decoded received signal and to produce a first quality indication; re-encoding at said first data rate said first decoded received signal to produce a first received signal prediction; comparing said first received signal prediction to said received signal and counting a first number of errors, wherein an error occurs when said received signal does not match said first received signal prediction, and wherein said first number of errors and said first quality indication define a first error metric; decoding at a second data rate said received signal to produce a second decoded received signal and to produce a second quality indication; re-encoding at said second data rate said second decoded received signal to produce a second received signal prediction; comparing said second received signal prediction to said received signal and counting a second number of errors, wherein an error occurs when said received signal does not match said second received signal prediction, and wherein said second number of errors and said second quality indication define a second error metric; decoding at a third data rate said received signal to produce a third decoded received signal and to produce a third quality indication; re-encoding at said third data rate said third decoded received signal to produce a third received signal prediction; comparing said third received signal prediction to said received signal and counting a third number of errors, wherein an error occurs when said received signal does not match said third received signal prediction, and wherein said third number of errors and said third quality indication define a third error metric; and predicting said unknown data rate based on a comparison of each of said error metrics.

Claim 24

In a receiver of a variable-rate communication system, a method for decoding a received signal at an unknown data rate comprising the steps of: decoding at a first data rate said received signal to produce a first decoded received signal and to produce a first quality indication; re-encoding at said first data rate said first decoded received signal to produce a first received signal prediction; comparing said first received signal prediction to said received signal and counting a first number of errors, wherein an error occurs when said received signal does not match said first received signal prediction, and wherein said first number of errors and said first quality indication define a first error metric; decoding at a second data rate said received signal to produce a second decoded received signal and to produce a second quality indication; re-encoding at said second data rate said second decoded received signal to produce a second received signal prediction; comparing said second received signal prediction to said received signal and counting a second number of errors, wherein an error occurs when said received signal does not match said second received signal prediction, and wherein said second number of errors and said second quality indication define a second error metric; decoding at a third data rate said received signal to produce a third decoded received signal and to produce a third quality indication; re-encoding at said third data rate said third decoded received signal to produce a third received signal prediction; comparing said third received signal prediction to said received signal and counting a third number of errors, wherein an error occurs when said received signal does not match said third received signal prediction, and wherein said third number of errors and said third quality indication define a third error metric; and predicting said unknown data rate based on a comparison of each of said error metrics.

Claim 25

The method of claim 21 wherein said first quality indication, said second quality indication, and said third quality indication are each a single bit quality indication wherein a "1" indicates a high probability of successful decoding at said data rate corresponding to said quality indication and a "0" indicates a high probability of defective decoding at said data rate corresponding to said quality indication.

Claim 26

The method of claim 22 wherein said step of predicting comprises the step of predicting a first predicted data rate if said first quality indication is equal to "1" and if said first number of errors is less than a threshold number.

Claim 27

The method of claim 22 wherein said step of predicting comprises the step of predicting said first data rate if said first quality indication is equal to "1" and said second quality indication is equal to "1" and if said first number of errors is less than or equal to said second number of errors plus a predetermined number.

Claim 28

The method of claim 22 wherein said first data rate is 14,400 bits per second.

Claim 29

In a receiver receiving a signal having an unknown data rate wherein said receiver decodes and re-encodes said signal at a plurality of data rates, generates a quality indication for each of said plurality of data rates, and compares each decoded and re-encoded signal with said signal, and counts a number of errors in said comparison, a method for decoding said signal comprising the steps of: selecting a first data rate if said quality indication corresponding to said first data rate indicates successful decoding at said first data rate and if said number of errors corresponding to said first data rate is less than a first threshold; and selecting a second data rate if said quality indication corresponding to said first data rate indicates successful decoding and said quality indication corresponding to said second data rate indicates successful decoding and if said number of errors corresponding to said first data rate exceeds a second threshold.

Claim 30

In a receiver receiving a signal having an unknown data rate wherein said receiver decodes and re-encodes said signal at a plurality of data rates, generates a quality indication for each of said plurality of data rates, and compares each decoded and re-encoded signal with said signal, and counts a number of errors in said comparison, a method for decoding said signal comprising the steps of: selecting a first data rate if said quality indication corresponding to said first data rate indicates successful decoding at said first data rate and if said number of errors corresponding to said first data rate is less than a first threshold; and selecting a second data rate if said quality indication corresponding to said first data rate indicates successful decoding and said quality indication corresponding to said second data rate indicates successful decoding and if said number of errors corresponding to said first data rate exceeds a second threshold.

Claim 31

The method for decoding of claim 26 wherein said first threshold is a predetermined constant.

Claim 32

The method for decoding of claim 26 wherein said first threshold is a predetermined constant plus said number of errors corresponding to said second data rate.

Claim 33

The method for decoding of claim 26 wherein said first threshold and said second threshold are equal and are a predetermined constant plus said number of errors corresponding to said second data rate.

Claim 34

The method for decoding of claim 26 further comprising the steps of: selecting said second data rate if said quality indication corresponding to said first data rate indicates unsuccessful decoding at said first data rate and if said quality indication corresponding to said second data rate indicates successful decoding at said second data rate and if said quality indication corresponding to a third data rate indicates unsuccessful decoding at said third data rate and if said quality indication corresponding to a fourth data rate indicates successful decoding at said fourth data rate and said number of errors corresponding to said second data rate is less than or equal to a third threshold.

Claim 35

The method for decoding of claim 30 wherein said third threshold is a predetermined constant plus said number of errors corresponding to said fourth data rate.

Claim 36

The method for decoding of claim 26 further comprising the step of: selecting a fourth data rate if said quality indication corresponding to said first data rate indicates unsuccessful decoding at said first data rate and if said quality indication corresponding to said second data rate indicates successful decoding at said second data rate and if said quality indication corresponding to a third data rate indicates unsuccessful decoding at said third data rate and if said quality indication corresponding to said fourth data rate indicates successful decoding at said fourth data rate and said number of errors corresponding to said second data rate exceeds a third threshold.

Claim 37

The method for decoding of claim 32 wherein said third threshold is a predetermined constant plus said number of errors corresponding to said fourth data rate.

Claim 38

The method for decoding of claim 26 further comprising the step of: selecting said second data rate if said quality indication corresponding to said first data rate indicates unsuccessful decoding at said first data rate and if said quality indication corresponding to said second data rate indicates successful decoding at said second data rate and if said quality indication corresponding to a third data rate indicates unsuccessful decoding at said third data rate and if said quality indication corresponding to said fourth data rate indicates unsuccessful decoding at said fourth data rate.

Claim 39

The method for decoding of claim 26 further comprising the steps of: selecting said second data rate if said quality indication corresponding to said first data rate indicates unsuccessful decoding at said first data rate and if said quality indication corresponding to said second data rate indicates successful decoding at said second data rate and if said quality indication corresponding to a third data rate indicates successful decoding at said third data rate and if said quality indication corresponding to said fourth data rate indicates successful decoding at said fourth data rate and said number of errors corresponding to said second data rate is less than or equal to said number of error corresponding to said third data rate plus a fixed constant.

Claim 40

The method for decoding of claim 26 further comprising the step of: selecting said third data rate if said quality indication corresponding to said first data rate indicates unsuccessful decoding at said first data rate and if said quality indication corresponding to said second data rate indicates successful decoding at said second data rate and if said quality indication corresponding to a third data rate indicates successful decoding at said third data rate and if said quality indication corresponding to said fourth data rate indicates successful decoding at said fourth data rate and said number of errors corresponding to said second data rate exceeds said number of error corresponding to said third data rate plus a fixed constant.

Claim 41

The method for decoding of claim 26 further comprising the steps of: selecting a fourth data rate if said quality indication corresponding to said first data rate indicates unsuccessful decoding at said first data rate and if said quality indication corresponding to said second data rate indicates unsuccessful decoding at said second data rate and if said quality indication corresponding to a third data rate indicates unsuccessful decoding at said third data rate and if said quality indication corresponding to said fourth data rate indicates successful decoding at said fourth data rate and said number of errors corresponding to said fourth data rate is less than or equal a third predetermined threshold.

Claim 46

In a receiver receiving a signal having an unknown data rate wherein said receiver Viterbi decodes and re-encodes said signal at a plurality of data rates, generates a quality indication for each of said plurality of data rates, and compares each Viterbi decoded and re-encoded signal with said signal, and counts a number of errors in said comparison, a method for decoding said signal comprising the steps of: selecting a first data rate if said quality indication corresponding to said first data rate indicates successful decoding at said first data rate and if said number of errors corresponding to said first data rate is less than a first threshold; and selecting a second data rate if said quality indication corresponding to said first data rate indicates successful decoding and said quality indication corresponding to said second data rate indicates successful decoding and if said number of errors corresponding to said first data rate exceeds a second threshold.

Claim 47

In a receiver receiving a signal having an unknown data rate wherein said receiver Viterbi decodes and re-encodes said signal at a plurality of data rates, generates a quality indication for each of said plurality of data rates, and compares each Viterbi decoded and re-encoded signal with said signal, and counts a number of errors in said comparison, a method for decoding said signal comprising the steps of: selecting a first data rate if said quality indication corresponding to said first data rate indicates successful decoding at said first data rate and if said number of errors corresponding to said first data rate is less than a first threshold; and selecting a second data rate if said quality indication corresponding to said first data rate indicates successful decoding and said quality indication corresponding to said second data rate indicates successful decoding and if said number of errors corresponding to said first data rate exceeds a second threshold.

Claim 48

The method for decoding of claim 40 wherein said first threshold is a predetermined constant.

Claim 49

The method for decoding of claim 40 wherein said first threshold is a predetermined constant plus said number of errors corresponding to said second data rate.

Claim 50

The method for decoding of claim 40 wherein said first threshold and said second threshold are equal and are a predetermined constant plus said number of errors corresponding to said second data rate.

Claim 51

The method for decoding of claim 40 further comprising the step of selecting said second data rate if said quality indication corresponding to said first data rate indicates unsuccessful decoding at said first data rate and if said quality indication corresponding to said second data rate indicates successful decoding at said second data rate and if said quality indication corresponding to a third data rate indicates unsuccessful decoding at said third data rate and if said quality indication corresponding to a fourth data rate indicates successful decoding at said fourth data rate and said number of errors corresponding to said second data rate is less than or equal to a third threshold.

Claim 52

The method for decoding of claim 44 wherein said third threshold is a predetermined constant plus said number of errors corresponding to said fourth data rate.

Claim 53

The method for decoding of claim 40 further comprising the step of selecting a fourth data rate if said quality indication corresponding to said first data rate indicates unsuccessful decoding at said first data rate and if said quality indication corresponding to said second data rate indicates successful decoding at said second data rate and if said quality indication corresponding to a third data rate indicates unsuccessful decoding at said third data rate and if said quality indication corresponding to said fourth data rate indicates successful decoding at said fourth data rate and said number of errors corresponding to said second data rate exceeds a third threshold.

Claim 54

The method for decoding of claim 46 wherein said third threshold is a predetermined constant plus said number of errors corresponding to said fourth data rate.

Claim 55

The method for decoding of claim 40 further comprising the step of selecting said second data rate if said quality indication corresponding to said first data rate indicates unsuccessful decoding at said first data rate and if said quality indication corresponding to said second data rate indicates successful decoding at said second data rate and if said quality indication corresponding to a third data rate indicates unsuccessful decoding at said third data rate and if said quality indication corresponding to said fourth data rate indicates unsuccessful decoding at said fourth data rate.

Claim 56

The method for decoding of claim 40 further comprising the steps of selecting said second data rate if said quality indication corresponding to said first data rate indicates unsuccessful decoding at said first data rate and if said quality indication corresponding to said second data rate indicates successful decoding at said second data rate and if said quality indication corresponding to a third data rate indicates successful decoding at said third data rate and if said quality indication corresponding to said fourth data rate indicates successful decoding at said fourth data rate and said number of errors corresponding to said second data rate is less than or equal to said number of error corresponding to said third data rate plus a fixed constant.

Claim 57

The method for decoding of claim 40 further comprising the step of selecting said third data rate if said quality indication corresponding to said first data rate indicates unsuccessful decoding at said first data rate and if said quality indication corresponding to said second data rate indicates successful decoding at said second data rate and if said quality indication corresponding to a third data rate indicates successful decoding at said third data rate and if said quality indication corresponding to said fourth data rate indicates successful decoding at said fourth data rate and said number of errors corresponding to said second data rate exceeds said number of error corresponding to said third data rate plus a fixed constant.

Claim 58

The method for decoding of claim 40 further comprising the step of selecting a fourth data rate if said quality indication corresponding to said first data rate indicates unsuccessful decoding at said first data rate and if said quality indication corresponding to said second data rate indicates unsuccessful decoding at said second data rate and if said quality indication corresponding to a third data rate indicates unsuccessful decoding at said third data rate and if said quality indication corresponding to said fourth data rate indicates successful decoding at said fourth data rate and said number of errors corresponding to said fourth data rate is less than or equal a third predetermined threshold.