# US 8,542,759 B2 · Method for transmitting a signal from a transmitter to a receiver in a power line communication network, transmitter, receiver, power line communication modem and power line communication system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,542,759 B2 - Document ID: US8542759B2 - Status: Granted - Kind: B2 - Application number: 13/601,697 - Filed: 2012-08-31 - Published: 2012-12-20 - Granted: 2013-09-24 - Earliest claimed: 2007-07-23 - Assignees: Sony Corporation - Applicants: Lothar Stadelmeier; Dietmar Schill; Andreas Schwager; Daniel Schneider - Inventors: Lothar Stadelmeier; Dietmar Schill; Andreas Schwager; Daniel Schneider - Web page: https://patentgrep.com/patent/US8542759B2 ## CPC - H04L 27/2601: {Multicarrier modulation systems} - H04B 3/54: Systems for transmission via power distribution lines - H04B 3/542: {the information being in digital form} - H04L 1/0693: {Partial feedback, e.g. partial channel state information [CSI]} - H04L 5/0025: {Spatial division following the spatial signature of the channel} - H04L 5/0058: {Allocation criteria} - H04L 5/0092: {Indication of how the channel is divided} - H04L 25/0248: {Eigen-space methods} - H04L 27/2646: {using feedback from receiver for adjusting OFDM transmission parameters, e.g. transmission timing or guard interval length} - H04L 27/2647: {Arrangements specific to the receiver only (equalisation H04L27/01)} - H04B 2203/5408: using protocols - H04B 2203/5425: improving S/N by matching impedance, noise reduction, gain control - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION ## Abstract A method for transmitting a signal from a transmitter over a channel to a receiver on a Power Line Network, wherein said signal is OFDM-modulated on a set of sub-carriers, is proposed, wherein an OFDM tonemap and an eigenbeamforming encoding matrix are determined based on a channel estimation for each sub-carrier, a tonemap feedback signal and an eigenbeamforming feedback signal are generated, which are descriptive of said OFDM tonemap and said eigenbeamforming encoding matrix, respectively, and transmitted to the transmitter. A corresponding receiver, a transmitter, a power line communication and a power line communication system are described as well. ## Claims ### Claim 1 A method for transmitting a signal between a transmitter and a receiver over a channel of a Power Line Network (PLN), wherein said signal is orthogonal frequency division multiplex (OFDM) modulated on a set of sub-carriers, and said PLN includes at least phase, neutral and protective line wires so that said PLN establishes multiple wired transmission paths, the method comprising: determining OFDM tonemap information and eigenbeamforming encoding information both based on a channel estimation for each sub-carrier; grouping eigenbeamforming encoding information of neighboring sub-carriers; generating an eigenbeamforming feedback signal, which is descriptive of said grouped eigenbeamforming encoding information; generating a tonemap feedback signal, which is descriptive of said OFDM tonemap information; and transmitting, over said PLN, information based on said eigenbeamforming feedback signal and said tonemap feedback signal from said receiver to said transmitter. ### Claim 2 (depends on 1) The method according to claim 1, comprising: generating a feedback signal based on said eigenbeamforming feedback signal and on said tonemap feedback signal; and transmitting said feedback signal from said receiver to said transmitter. ### Claim 3 (depends on 1) The method according to claim 1, comprising: determining an eigenbeamforming decoding matrix based on said channel estimation; and generating a payload signal in said receiver based on said eigenbeamforming decoding matrix. ### Claim 4 (depends on 2) The method according to claim 2, comprising: generating a compressed feedback signal by compressing said feedback signal prior to transmitting said feedback signal; and transmitting said compressed feedback signal from said receiver to said transmitter. ### Claim 5 (depends on 1) The method according to claim 1, comprising: storing a set of predetermined encoding matrices in said transmitter and said receiver together with corresponding identifiers of said encoding matrices; selecting in said receiver a representative encoding matrix from said set of predetermined encoding matrices, said representative encoding matrix corresponding to said eigenbeamforming encoding information; and transmitting the identifier of said representative encoding matrix to said transmitter within said eigenbeamforming feedback signal. ### Claim 6 (depends on 1) The method according to claim 1, comprising: receiving, over said multiple wired transmission paths of said PLN at the receiver, a training sequence using said set of sub-carriers; calculating for said PLN, the channel estimation for each sub-carrier based on said received training sequence for determining the OFDM tonemap information and the eigenbeamforming encoding information; receiving a further training sequence at said receiver; determining a further eigenbeamforming feedback signal or tonemap feedback signal based on a disturbed received version of said further training sequence; and transmitting said further eigenbeamforming feedback signal or said further tonemap feedback signal to said transmitter only in cases when it is different from said eigenbeamforming feedback signal or tonemap feedback signal, respectively. ### Claim 7 (depends on 1) The method according to claim 1, comprising: comparing OFDM tonemap information of different sub-carriers; and transmitting a common feedback signal, which is common for different sub-carriers, when said OFDM tonemap information for said different sub-carriers are the same. ### Claim 8 (depends on 1) The method according to claim 1, wherein The grouping comprises grouping of neighboring sub-carriers assigned to the same sub-carrier constellation. ### Claim 9 A method for transmitting a signal between a transmitter and a receiver over a channel of a Power Line Network (PLN), wherein said signal is orthogonal frequency division multiplex (OFDM) modulated on a set of sub-carriers, and said PLN includes at least phase, neutral and protective line wires so that said PLN establishes multiple wired transmission paths, the method comprising: determining OFDM tonemap information and eigenbeamforming encoding information, both based on a channel estimation for each sub-carrier; reducing the OFDM tonemap information by grouping neighboring sub-carriers and assigning a common OFDM tonemap information to each group of sub-carriers, generating an eigenbeamforming feedback signal, which is descriptive of said eigenbeamforming encoding information; generating a tonemap feedback signal, which is descriptive of said reduced OFDM tonemap information; and transmitting, over said PLN, information based on said eigenbeamforming feedback signal and said tonemap feedback signal from said receiver to said transmitter. ### Claim 10 (depends on 9) The method according to claim 9, comprising: generating a feedback signal based on said eigenbeamforming feedback signal and on said tonemap feedback signal; and transmitting said feedback signal from said receiver to said transmitter. ### Claim 11 (depends on 10) The method according to claim 10, comprising: generating a compressed feedback signal by compressing said feedback signal prior to transmitting said feedback signal; and transmitting said compressed feedback signal from said receiver to said transmitter. ### Claim 12 (depends on 9) The method according to claim 9, comprising: receiving, over said multiple wired transmission paths of said PLN at the receiver, a training sequence using said set of sub-carriers; calculating for said PLN, the channel estimation for each sub-carrier based on said received training sequence for determining the OFDM tonemap information and the eigenbeamforming encoding information; receiving a further training sequence at said receiver; determining a further eigenbeamforming feedback signal or tonemap feedback signal based on a disturbed received version of said further training sequence; and transmitting said further eigenbeamforming feedback signal or said further tonemap feedback signal to said transmitter only in cases when it is different from said eigenbeamforming feedback signal or tonemap feedback signal, respectively. ### Claim 13 A receiver for receiving a signal on a power line network (PLN), said PLN including at least phase, neutral and protective line wires so that said PLN establishes multiple wired transmission paths, said receiver comprising: a receiving unit including a plurality of orthogonal frequency division multiplex (OFDM) demodulators for demodulating signals received via sub-carriers of an OFDM-based signal transmitted via said PLN, said receiving unit configured to receive over said multiple wired transmission paths of said PLN, a training sequence using said set of sub-carriers, a channel estimation unit, connected to said receiving unit, said channel estimation unit being configured to determine OFDM tonemap information and eigenbeamforming encoding information based on a channel estimation for each sub-carrier based on said received training sequence, to group eigenbeamforming encoding information of neighboring sub-carriers, and to determine a tonemap feedback signal, which is descriptive of said OFDM tonemap information and to determine an eigenbeamforming feedback signal, which is descriptive of said grouped eigenbeamforming encoding information; and a transmitting unit, which is connected to said channel estimation unit and configured to transmit said eigenbeamforming feedback signal and said tonemap feedback signal to a transmitter via said PLN. ### Claim 14 (depends on 13) The receiver according to claim 13, wherein said transmitting unit is further configured to generate a feedback signal based on said eigenbeamforming feedback signal and said tonemap feedback signal and to transmit said feedback signal to said transmitter. ### Claim 15 (depends on 13) The receiver according to claim 13, comprising: a de-eigenbeamforming unit connected to said channel estimation unit; and a quadrature amplitude modulation (QAM) demodulation unit, connected to said de-eigenbeamforming unit and to said channel estimation unit, wherein said channel estimation unit is further configured to generate an eigenbeamforming decoding matrix and to transmit said eigenbeamforming decoding matrix to said de-eigenbeamforming unit and further configured to transmit said OFDM tonemap information to said QAM demodulation unit. ### Claim 16 (depends on 13) The receiver according to claim 13, wherein: said channel estimation unit is further configured to compare OFDM tonemap information of different sub-carriers; and said transmitting unit is further configured to transmit a common feedback signal, which is common for different sub carriers, when said OFDM tonemap information for said different sub-carriers are the same. ### Claim 17 (depends on 13) The receiver according to claim 13, wherein: said channel estimation unit is further configured to determine time-dependent repetitive patterns of said channel estimation, to divide said repetitive pattern of said channel estimation into parts, wherein within said parts said channel estimation remains essentially the same and to generate corresponding feedback signals for each of said parts; and said transmitter unit is further configured to transmit said corresponding feedback signals to said transmitter together with an indicator of said repetitive pattern. ### Claim 18 (depends on 13) The receiver according to claim 13, wherein: said channel estimation unit is further configured to determine time-dependent repetitive patterns of said channel estimation, to divide said repetitive pattern of said channel estimation into parts, wherein within said parts said channel estimation remains essentially the same and to generate corresponding feedback signals for each of said parts; and said transmitter unit is further configured to transmit said corresponding feedback signals to said transmitter together with an indicator of said repetitive pattern. ### Claim 19 A receiver for receiving a signal on a power line network (PLN), said PLN including at least phase, neutral and protective line wires so that said PLN establishes multiple wired transmission paths, said receiver comprising: a receiving unit including a plurality of orthogonal frequency division multiplex (OFDM) demodulators for demodulating signals received via sub-carriers of an OFDM-based signal transmitted via said PLN, said receiving unit configured to receive over said multiple wired transmission paths of said PLN, a training sequence using said set of sub-carriers, a channel estimation unit, connected to said receiving unit, said channel estimation unit configured to determine OFDM tonemap information and eigenbeamforming encoding information based on a channel estimation for each sub-carrier based on said received training sequence, to reduce the OFDM tonemap information by grouping neighboring sub-carriers and assigning a common OFDM tonemap information to each group of sub-carriers, and to determine a tonemap feedback signal, which is descriptive of said reduced OFDM tonemap information and to determine an eigenbeamforming feedback signal, which is descriptive of said eigenbeamforming encoding information; and a transmitting unit, which is connected to said channel estimation unit and configured to transmit said eigenbeamforming feedback signal and said tonemap feedback signal to a transmitter via said PLN. ### Claim 20 (depends on 19) The receiver according to claim 19, wherein said transmitting unit is further configured to generate a feedback signal based on said eigenbeamforming feedback signal and said tonemap feedback signal and to transmit said feedback signal to said transmitter. ### Claim 21 (depends on 19) The receiver according to claim 19, further comprising: a de-eigenbeamforming unit connected to said channel estimation unit; and a quadrature amplitude modulation (QAM) demodulation unit, connected to said de-eigenbeamforming unit and to said channel estimation unit, wherein said channel estimation unit is further configured to generate a eigenbeamforming decoding matrix and to transmit said eigenbeamforming decoding matrix to said de-eigenbeamforming unit and further configured to transmit said OFDM tonemap information to said QAM demodulation unit. ### Claim 22 (depends on 19) The receiver according to claim 19, wherein said transmitting unit is further configured to compare a current feedback signal with the last feedback signal that has been transmitted and to transmit said current feedback signal only in cases when it is different from said last feedback signal. ### Claim 23 (depends on 19) The receiver according to claim 19, wherein: the grouping comprises grouping of neighboring sub-carriers assigned to the same sub-carrier constellation. ### Claim 24 (depends on 19) The receiver according to claim 19, wherein: said channel estimation unit is further configured to determine time-dependent repetitive patterns of said channel estimation, to divide said repetitive pattern of said channel estimation into parts, wherein within said parts said channel estimation remains essentially the same and to generate corresponding feedback signals for each of said parts; and said transmitter unit is further configured to transmit said corresponding feedback signals to said transmitter together with an indicator of said repetitive pattern.