Correlation detecting apparatus, its detecting method and communication apparatus and its communication method
US6411664B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 1998 |
| Grant date | Jun 25, 2002 |
| Priority date | — |
| Expiry date | Aug 25, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2679
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A correlation detecting apparatus is capable of securely detecting a M sequence code forming a reference for timing even when a plurality of signals with different amplitudes are time division multiplexed includes matched filter (82) for detecting a predetermined code from a received signal, an average amplitude detector circuit (83) for detecting an average amplitude of the received signal, and a divider circuit (84) for normalizing an output of the matched filter (82) by an output of the average amplitude detector circuit 83 are provided. The output of the matched filter (82) normalized by the divider circuit (84) is compared with a threshold value for outputting a correlation detecting signal. When a received signal level is large, the output level of the matched filter (82) becomes large. However, in this case because the average amplitude of the received signal also becomes large, a divided value of the output level of the matched filter (82) by the output level of the average amplitude detector circuit (83) makes almost no change. In contrast to this, the output level of the matched filter when an M sequence is received remains nearly constant irrespective of an input signal …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.