Rate detection apparatus and method for variable rate speech encoding
AssigneeEricsson Inc.
InventorJiann-Ching Guey
Life of this patent
Estimating the term…
Abstract
A method of detecting the data rate of a received digital signal is provided. The method generally includes the steps of decoding a received signal at each of a plurality of possible rates to produce a plurality of decoded bit sequences and a corresponding plurality of correlation metrics, one for each of the plurality of different rates. Quality checks are performed on the plurality of decoded bit sequences producing a plurality of quality check indication signals, one for each of the plurality of different rates. The pluralities of correlation metrics and quality check indication signals are analyzed and the data rate of the received signal is determined based on a novel decision process.
Claims20
A method of detecting a data rate of a received signal comprising the steps of:
- decoding the received signal at a plurality of different rates producing a plurality of decoded bit sequences and a corresponding plurality of correlation metrics, one each for the plurality of different rates;
- performing quality checks on the plurality of decoded bit sequences producing a plurality of quality check indication signals, one each for the plurality of different rates, the quality check indication signals indicating a probability that the data rate of the received signal is the data rate at which the particular decoded bit sequence was decoded;
- comparing ratios of the plurality of correlation metrics with respective threshold values;
- determining the data rate of the received signal based on said comparison;
- analyzing the quality check indication signal associated with the determined data rate;
- and
- confirming the determined data rate based on said quality check indication signal.
An apparatus for detecting a data rate of a received signal comprising:
- means for decoding the received signal at a plurality of different rates and for producing a plurality of decoded bit sequences and a corresponding plurality of correlation metrics, one each for the plurality of different rates;
- means for performing quality checks on the plurality of decoded bit sequences producing a plurality of quality check indication signals, one each for the plurality of different rates, the quality check indication signals indicating a probability that the data rate of the received signal is the data rate at which the particular decoded bit sequence was decoded;
- a metric comparison circuit receiving the plurality of correlation metrics, comparing various ratios between the plurality correlation metrics with various threshold values, and developing check bits indicative of whether a particular ratio exceeded a particular threshold value;
- a rate determination block receiving the check bits and developing a first signal indicative of a determined data rate of the received signal;
- and
- a validation circuit receiving the quality check indication signals and the first signal and developing a second signal, based on an analysis of the quality check indication signals and the first signal, assigning the received signal a data rate.
An apparatus for detecting a data rate of a received signal comprising:
- means for decoding the received signal at a plurality of different rates and for producing a plurality of decoded bit sequences and a corresponding plurality of correlation metrics, one each for the plurality of different rates;
- means for performing quality checks on the plurality of decoded bit sequences producing a plurality of quality check indication signals, one each for the plurality of different rates, the quality check indication signals indicating a probability that the data rate of the received signal is the data rate at which the particular decoded bit sequence was decoded;
- a validation circuit receiving the quality check indication signals and developing a first signal indicative of which quality check indication signals indicate a high probability that the data rate of the received signal is the data rate at which the particular decoded bit sequence was decoded;
- and
- a rate determination block receiving the plurality of correlation metrics and the first signal, comparing, with threshold values, correlation metric ratios of only the correlation metrics whose corresponding quality check indication signal indicates a high probability that the data rate of the received signal is the data rate at which the particular decoded bit sequence was decoded, and developing a second signal assigning the received signal a data rate based on said comparison.
Dependencies are inferred from the claim text.