US 5,406,551 A · Method and apparatus for digital signal transmission using orthogonal frequency division multiplexing

Abstract

A digital signal transmission using OFDM modulation scheme in which the valid transmission data can be reproduced without requiring a recovery of the carriers at a receiver side. On a transmitter side, the transmission data sequence in which predetermined reference data for each carrier are placed among valid transmission data is modulated according to an orthogonal frequency division multiplexing (OFDM) modulation scheme using a plurality of carriers and obtained OFDM transmission signals are transmitted. On a receiver side, the received OFDM transmission signals are demodulated to obtain received data sequence containing valid received data and received reference data, and the valid transmission data are estimated from the received data sequence according to the valid received data, the received reference data, and the predetermined reference data for each carrier.

Claims20

Dependent claims

A method for digital signal transmission frequency division multiplexing, comprising the steps of:

(a) obtaining transmission data sequence by placing predetermined reference data for each carrier of a plurality of carriers among valid transmission data, the predetermined reference data indicating amplitude and phase of prescribed reference points;
(b) modulating said plurality of carriers with the transmission data sequence obtained at the step (a) according to an orthogonal frequency division multiplexing (OFDM) modulation schedule to obtain OFDM transmission signals;
(c) transmitting the OFDM transmission signals obtained at the step (b) to a transmission path;
(d) receiving the OFDM transmission signals from the transmission path;
(e) demodulating the OFDM transmission signals received at the step (d) to obtain received data sequence containing valid received data and received reference data;
and
(f) estimating the valid transmission data used at the step (a) from the received data sequence obtained at the step (e) according to the valid received data, the received reference data, and said predetermined reference data for each carrier.

4 more elements

A transmitter device for digital signal transmission frequency division multiplexing, comprising:

means for obtaining transmission data sequence by placing predetermined reference data for each carrier of a plurality of carriers among valid transmission data, the predetermined reference data indicating amplitude and phase of prescribed reference points;
modulator means for modulating said plurality of carriers with the transmission data sequence obtained by the obtaining means according to an orthogonal frequency division multiplexing (OFDM) modulation scheme to obtain OFDM transmission signals;
and
means for transmitting the OFDM transmission signals obtained by the modulator means to a transmission path.

1 more element

A receiver device for digital signal transmission frequency division multiplexing, comprising:

means for receiving transmission signals from a transmission path, the transmission signals being obtained by modulating a plurality of carriers with transmission data sequence in which predetermined reference data for each carrier are placed among valid transmission data, according to an orthogonal frequency division multiplexing (OFDM) modulation scheme, the predetermined reference data indicating amplitude and phase of prescribed reference points:
demodulator means for demodulating the transmission signals received by the receiving means to obtain received data sequence containing valid received data and received reference data;
and
means for estimating valid transmission data from the received data sequence obtained by the demodulator means according to the valid received data, the received reference data, and said predetermined reference data for each carrier.

1 more element

Dependencies are inferred from the claim text.

Method and apparatus for digital signal transmission using orthogonal frequency division multiplexing

Life of this patent

Method and apparatus for digital signal transmission using orthogonal frequency division multiplexing

Life of this patent

Abstract

Claims20