Orthogonal frequency division multiplex demodulation
US5506836A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 1994 |
| Grant date | Apr 9, 1996 |
| Priority date | — |
| Expiry date | Jul 27, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2679
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An orthogonal frequency division multiplex (OFDM) demodulation apparatus which accurately reproduces a clock and accurately generates a time window for discrete Fourier transformation (DFT) for stable demodulation of an OFDM modulated signal, wherein a clock reproduction circuit of the OFDM demodulation apparatus includes a Costas computation circuit and processes a signal corresponding to the specific carrier wave signal of a predetermined single wave for each symbol out of the I and Q channel signals obtained by subjecting the OFDM modulated signal to DFT to generate a control voltage using the Costas computation circuit and low pass filters and operates a voltage control oscillator to reproduce a clock signal. The clock signal is divided to produce the time window signals used in the DFT circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.