Patent US3579978A successfully refreshed from Google Patents.
Patent EP0553841A2 successfully refreshed from Google Patents.
EP0553841A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method and apparatus for digital signal transmission using orthogonal frequency division multiplexing
Assignee: Japan Broadcasting Corp
•
Filing: 1993-01-29
•
Granted: —
•
Expires: 2013-01-29
Abstract
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.
Inventors
- 👤 Masafumi c/o NIPPON HOSO KYOKAI Saito
- 👤 Toru c/o NIPPON HOSO KYOKAI Kuroda
- 👤 Shigeki c/o NIPPON HOSO KYOKAI Moriyama
- 👤 Tomohiro c/o NIPPON HOSO KYOKAI Saito
- 👤 Masayuki c/o NIPPON HOSO KYOKAI Takada
- 👤 Osamu c/o NIPPON HOSO KYOKAI Yamada
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 12:01
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/26; H04L27/2601; H04L27/2602; H04L27/261; H04L27/2613; H04L27/2647; H04L27/2655; H04L27/2657; H04L27/32; H04L27/34; H04L27/2662; H04L27/2668; H04L27/2673; H04L27/2675; H04L5/00; H04L5/0001; H04L5/0003; H04L5/0005; H04L5/0007; H04L5/003; H04L5/0048
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
159 words
A method for digital signal transmission, comprising the steps of: (a) obtaining transmission data sequence by placing predetermined reference data for each carrier among valid transmission data, the predetermined reference data indicating amplitude and phase of prescribed reference points; (b) modulating a plurality of carriers with the transmission data sequence obtained at the step (a) according to an orthogonal frequency division multiplexing (OFDM) modulation scheme 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 the predetermined reference data for each carrier.
Claim 2
Dependent Claim
97 words
The method of claim 1, wherein at the step (a), the transmission data sequence is obtained in units of frames, where each frame contains a plurality of transmission symbols and each transmission symbol is carried by the plurality of carriers, and wherein at the step (f), the valid transmission data D TX is estimated from the valid received data D RX , the received reference data S RX , and the predetermined reference data S TX by calculating an equation: D TX = D RX · S TX /S RX for each carrier in each transmission symbol.
Claim 3
Dependent Claim
30 words
The method of claim 1, wherein the predetermined reference data for each carrier is set to be different from the predetermined reference data for carriers other than said each carrier.
Claim 4
Dependent Claim
122 words
The method of claim 1, wherein at the step (a), the transmission data sequence is obtained in units of frames, where each frame contains a plurality of transmission symbols and each transmission symbol is carried by the plurality of carriers, and the predetermined reference data are placed among the valid transmission data such that a fraction of said plurality of carriers for carrying said each transmission symbol carry the predetermined reference data for the fraction of said plurality of carriers while a remaining part of said plurality of carriers for carrying said each transmission symbol carry the valid transmission data, and the predetermined reference data for all of said plurality of carriers are distributed among a prescribed number of the transmission symbols.
Claim 5
Dependent Claim
62 words
The method of claim 4 wherein at the step (a), the predetermined reference data are placed among the valid transmission data such that, in an m-th transmission symbol, an n-th carrier carries the predetermined reference data for the n-th carrier only when a condition of " n mod k = m mod k " holds, where k, m, and n are integers.
Claim 6
Dependent Claim
22 words
The method of claim 1, wherein at the step (b), each of said plurality of carriers is modulated by a multi-level modulation.
Claim 7
Dependent Claim
88 words
A transmitter device for digital signal transmission, comprising: means for obtaining transmission data sequence by placing predetermined reference data for each carrier among valid transmission data, the predetermined reference data indicating amplitude and phase of prescribed reference points; modulator means for modulating a 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.
Claim 8
Dependent Claim
42 words
The transmitter device of claim 7, wherein the obtaining means obtains the transmission data sequence by using the predetermined reference data for each carrier which is set to be different from the predetermined reference data for carriers other than said each carrier.
Claim 9
Dependent Claim
121 words
The transmitter device of claim 7, wherein the obtaining means obtains the transmission data sequence in units of frames, where each frame contains a plurality of transmission symbols and each transmission symbol is carried by the plurality of carriers, and the obtaining means obtains the transmission data sequence by placing the predetermined reference data among the valid transmission data such that a fraction of said plurality of carriers for carrying said each transmission symbol carry the predetermined reference data while a remaining part of said plurality of carriers for carrying said each transmission symbol carry the valid transmission data, and the predetermined reference data for all of said plurality of carriers are distributed among a prescribed number of the transmission symbols.
Claim 10
Dependent Claim
67 words
The transmitter device of claim 9, wherein the obtaining means obtains the transmission data sequence by placing the predetermined reference data among the valid transmission data such that, in an m-th transmission symbol, an n-th carrier carries the predetermined reference data for the n-th carrier only when a condition of " n mod k = m mod k " holds, where k, m, and n are integers.
Claim 11
Dependent Claim
21 words
The transmitter device of claim 7, wherein the modulator means modulates each of said plurality of carriers by a multi-level modulation.
Claim 12
Dependent Claim
135 words
The transmitter device of claim 7, wherein the obtaining means further comprises: interleave matrix means for interleaving the valid transmission data; reference data memory means for memorizing the predetermined reference data for each carrier; switch means for selectively connecting one of the interleave matrix means and the reference data memory means to the modulator means so as to supply the transmission data sequence in which the predetermined reference data for each carrier memorized by the reference data memory means are placed among the valid transmission data interleaved by the interleave matrix means to the modulator means; and switch control means for controlling an switching operation by the switch means according to a prescribed reference data position information indicating prescribed positions in the transmission data sequence at which the predetermined reference data are to be placed.
Claim 13
Dependent Claim
128 words
A receiver device for digital signal transmission, 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 the predetermined reference data for each carrier.
Claim 14
Dependent Claim
90 words
The receiver device of claim 13, wherein the transmission data sequence is given in units of frames, where each frame contains a plurality of transmission symbols and each transmission symbol is carried by said plurality of carriers, and estimating means estimates the valid transmission data D TX from the valid received data D RX , the received reference data S RX , and the predetermined reference data S TX by calculating an equation: D TX = D RX · S TX /S RX for each carrier in each transmission symbol.
Claim 15
Dependent Claim
31 words
The receiver device of claim 13, wherein the predetermined reference data for each carrier is set to be different from the predetermined reference data for carriers other than said each carrier.
Claim 16
Dependent Claim
111 words
The receiver device of claim 13, wherein the transmission data sequence is given in units of frames, where each frame contains a plurality of transmission symbols and each transmission symbol is carried by said plurality of carriers, and the predetermined reference data are placed among the valid transmission data such that a fraction of said plurality of carriers for carrying said each transmission symbol carry the predetermined reference data while a remaining part of said plurality of carriers for carrying said each transmission symbol carry the valid transmission data, and the predetermined reference data for all of said plurality of carriers are distributed among a prescribed number of the transmission symbols.
Claim 17
Dependent Claim
59 words
The receiver device of claim 16, wherein the predetermined reference data are placed among the valid transmission data such that, in an m-th transmission symbol, an n-th carrier carries the predetermined reference data for the n-th carrier only when a condition of " n mod k = m mod k " holds, where k, m, and n are integers.
Claim 18
Dependent Claim
19 words
The receiver device of claim 13, wherein each of said plurality of carriers is modulated by a multi-level modulation.
Claim 19
Dependent Claim
30 words
The receiver device of claim 13, further comprising means for separating the valid received data and the received reference data from the received data sequence obtained by the demodulator means.
Claim 20
Dependent Claim
154 words
The receiver device of claim 19, wherein the separating means further comprises: de-interleave matrix means for de-interleaving the valid received data; received reference data memory means for memorizing the received reference data for each carrier; switch means for connecting the demodulator means with one of the de-interleave matrix means and the received reference data memory means selectively such that the demodulator means is connected with the de-interleave matrix means while the demodulator means outputs sections of the received data sequence containing the valid received data, whereas the demodulator means is connected with the received reference data memory means while the demodulator means outputs sections of the received data sequence containing the received reference data; and switch control means for controlling an switching operation by the switch means according to a prescribed reference data position information indicating prescribed positions in the received data sequence at which the received reference data are supposed to be placed.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.