Bad frame indicator for radio telephone receivers
AssigneeBroadcom Corporation
InventorYue Chen
Life of this patent
Estimating the term…
Abstract
A method for identifying a bad GSM speed frame and simultaneously maintaining a frame erasure rate below a specified value. The method is based upon a joint use of four signal quality metrics: (1) frame CRC parity check; (2) estimated burst signal-to-noise ratio; (3) estimated frame bit error count; and (4) stealing flag values of a frame. Another feature includes providing an improved estimated burst signal-to-noise ratio.
Claims20
In a radio communication system, a method for operating a receiver to determine that a received speech frame is bad, the method comprising:
- receiving a plurality of bursts that make up the speech frame, wherein each of the plurality of bursts includes coded speech data and a received training sequence;
- for each of the plurality of bursts:
- performing a plurality of correlation operations on a respective received training sequence using a local sequence to produce a plurality of correlation sequences, each correlation sequence including a plurality of correlation values and being respective to a contiguous portion of the training sequence;
- separately summing the correlation values of the correlation sequences to produce a plurality of sums;
- based upon a maximum one of the plurality of sums determining an estimated signal power;
- determining an estimated noise power based upon the received training sequence;
- and
- based upon the estimated signal power and the estimated noise power, determining an estimated signal-to-noise ratio (ESNR) for the respective burst;
- and
- when the ESNR of the plurality of bursts compare unfavorably to an ESNR criteria, determining that the speech frame is bad.
In a radio communication system, a method for operating a receiver to determine that a received speech frame is bad, the method comprising:
- receiving a plurality of bursts that make up the speech frame, wherein the plurality of bursts includes a data portion, at least one stealing flag, and a received training sequence, wherein a stealing flag indicates whether coded speech data in a data portion of a respective burst has been preempted with control data;
- determining an absolute value of the sum of the stealing flags contained in the plurality of bursts;
- determining an estimated bit error count (EBEC) for the speech frame based upon the plurality of bursts;
- and
- when the absolute value of the sum of the stealing flags contained in the plurality of bursts compares unfavorably to a first threshold and the EBEC for the speech frame compares unfavorably to a second threshold, determining that the speech frame is bad.
In a radio communication system, a method for operating a receiver to determine that a received speech frame is bad, the method comprising:
- receiving a plurality of bursts that make up the speech frame, wherein the plurality of bursts includes a data portion, at least one stealing flag, and a received training sequence, wherein a stealing flag indicates whether coded speech data in a data portion of a respective burst has been preempted with control data;
- determining an estimated signal-to-noise ratio (ESNR) for each of the plurality of bursts;
- determining an absolute value of the sum of the stealing flags contained in the plurality of bursts;
- determining an estimated bit error count (EBEC) for the speech frame based upon the plurality of bursts;
- when the absolute value of the sum of the stealing flags contained in the plurality of bursts compares unfavorably to a first threshold and the EBEC for the speech frame compares unfavorably to a second threshold, determining that the speech frame is bad;
- and
- when the ESNR of the plurality of bursts compare unfavorably to an ESNR criteria, determining that the speech frame is bad.
Dependencies are inferred from the claim text.