Method and apparatus for performing rate determination using orthogonal rate-dependent walsh covering codes
US6147964A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 7, 1998 |
| Grant date | Nov 14, 2000 |
| Priority date | — |
| Expiry date | May 7, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L1/08
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for rate determination in a communication system using orthogonal rate-dependent Walsh covering codes. Orthogonal rate-dependent Walsh codes are used to cover repeated code symbols prior to transmission over a communication link. In one embodiment, the Walsh codes comprise orthogonal binary codes that increase by powers of two for each data rate used in the system. Code symbols are repeated and then covered at the symbol rate using the inventive orthogonal Walsh codes. The inventive code symbol repetition and encoding method and apparatus is particularly advantageous in encoding data that contains long sequences of logical zeros and ones. The orthogonal nature of the code symbols encoded in accordance with the present invention allows use of a more accurate and less complex data rate determination apparatus in the receiver. Rate determination is thereby improved resulting in an improvement in data service capability and a reduction in decoding errors. In one embodiment, symbol error rate (SER) blocks are used to generate rate-dependent SER metrics for each of the candidate rates. SER estimators associated with soft combiners using incorrect data rate hypothes…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.