The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 17, 2009
Filed:
Oct. 23, 2003
Guoqiang Xue, Nepean, CA;
Xixlan Chen, Nepean, CA;
Guoqiang Xue, Nepean, CA;
Xixlan Chen, Nepean, CA;
Nortel Networks Limited, St. Laurent, Quebec, CA;
Abstract
This invention enables determining whether a received frame is an erasure, a DTX mode frame or a CONT mode frame, using a metric m derived from the log likelihood ratio (LLR). The new metric is obtained by calculating the mean for the LLRs for a frame; a threshold T for this metric is also established. A received frame is declared a CONT frame if the CRC value indicates a successfully recovered frame, and m>T. A received frame is a DTX frame if m<T. Finally, a frame is declared an erasure if the CRC value indicates a failed frame, and m>T. The mean absolute LLR may also be used for determining the transmission rate of the system. In this case, a voice frame is decoded for all rates available; the transmission rate is that which corresponds to a passed CRC and has the highest m.