Method for partially modulating and demodulating data in a multi-carrier transmission system
US5715280A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1996 |
| Grant date | Feb 3, 1998 |
| Priority date | — |
| Expiry date | Jun 20, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2647
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A decoder and an encoder for extracting a subset of symbols from, or inserting a subset of symbols into, a communication channel in which M symbols are transmitted as the amplitudes of M sinusoidal carriers. The decoder recovers K symbols, S.sub.p . . . S.sub.p+K-1, from an analog signal generated by modulating M sinusoidal carriers for a frame period. Each carrier is modulated with an amplitude proportional to the value of one of M symbols, the i.sup.th carrier being modulated by symbol S.sub.i. The K symbols are a contiguous subset of the M symbols. The decoder includes a down-converter for down-converting to the modulated signal on the communication channel to generate a down-converted signal in which the carriers corresponding to S.sub.p . . . S.sub.p+K-1 occupy frequencies starting from 0. An analog-digital converter generates K time-domain samples in each frame period from the down-converted signal. These time-domain samples are converted to K frequency-domain values representing the symbols S.sub.p . . . S.sub.p+k-1 by a time-domain to frequency-domain overlapped transform. The encoder encodes K symbols, S.sub.1 . . . S.sub.K, as the amplitudes of K sinusoidal carriers, the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.