Abstract: This application relates to the field of communication technologies, and specifically, to a data transmission method and apparatus. One example method includes: receiving, by a controller, a performance parameter sent by each of the access points, wherein the performance parameter indicates communication performance between the access point that sends the performance parameter and a first station; determining, by the controller based on each received performance parameter, an access point set configured to provide a data transmission service for the first station, wherein the access point set comprises at least one of the plurality of access points; and when the access point set comprises at least two access points, determining, by the controller, a data transmission mode between each of the access points in the access point set and the first station based on the performance parameter sent by each of the access points in the access point set.

Abstract: This application relates to the field of communications technologies, and discloses a Wi-Fi communication method and an electronic device. The method includes the following steps: An AP device is connected to a first device by using a target channel. The AP device supports full-duplex communication. On this basis, when the target channel is idle, the AP device sends a control message to the first device by using the target channel, where the control message includes a time period in which the AP device occupies the target channel. The first device determines, based on the time period, a time for sending a first data frame, where the sending time is in the time period. Then the first device sends the first data frame to the AP device at the sending time by using the target channel.

Abstract: A signal processing method and system includes a baseband signal baseband signal processing module configured to perform slow envelope processing on a first signal, to obtain an envelope value E(n) of the first signal on which the slow envelope processing has been performed, obtain a phase value ?(n) based on E(n), where ?(n) and E(n) are in a linear relationship, and separate the first signal into a second signal and a third signal based on ?(n), where a phase difference between the second signal and the third signal is 2 ?(n), an amplifier configured to amplify the second signal and the third signal, and a synthesizer is configured to combine the amplified second signal and third signal to obtain a fourth signal.

Abstract: A signal processing method and system includes a baseband signal baseband signal processing module configured to perform slow envelope processing on a first signal, to obtain an envelope value E(n) of the first signal on which the slow envelope processing has been performed, obtain a phase value ?(n) based on E(n), where ?(n) and E(n) are in a linear relationship, and separate the first signal into a second signal and a third signal based on ?(n), where a phase difference between the second signal and the third signal is 2 ?(n), an amplifier configured to amplify the second signal and the third signal, and a synthesizer is configured to combine the amplified second signal and third signal to obtain a fourth signal.

Abstract: A method and an apparatus for determining a time offset are disclosed. The method includes: obtaining, by a device at a head end, a time-domain signal based on a received signal; and then determining a time offset based on values of peak-to-average ratios of a preset quantity of symbols starting from a qth symbol in the time-domain signal, where a peak-to-average ratio of the qth symbol is greater than a preset threshold. A new method for determining a time offset is provided, and takes advantages that the time-domain signal obtained by the device at the head end has stronger capabilities of resisting interference such as frequency offset and phase noise. The method for determining a time offset can be applied both to initial ranging and periodic ranging.

Abstract: A predistortion method and apparatus, wherein the predistortion method includes: sending a first sequence, and storing the sent first sequence; receiving a second sequence that is fed back, where the second sequence is a sequence obtained after sampling is performed on the first sequence that suffers distortion; obtaining a third sequence after performing sampling on the stored first sequence, where a sampling rate for obtaining the third sequence through sampling is the same as a sampling rate for obtaining the second sequence through sampling; and determining, based on the second sequence and the third sequence, a linear distortion coefficient corresponding to each of at least one Nyquist interval in a spectrum for sending a signal, where the linear distortion coefficient is used to perform linear compensation on the sent signal.

Abstract: A decoding method and a decoder for a low-density parity-check (LDPC) code, where the method includes dividing, by a decoder, an LDPC code C whose bit length is n into k LDPC codes D={D1,D2,K,Dk-1,Dk}, arranging, by the decoder, Di, i=1,2,K,k?1,k by column to obtain transpose codes DT={D1T,D2T,K,Dk-1T,DkT} of the LDPC codes D, performing cyclic shift on DiT,i=1,2,K,k?1,k by row according to values of corresponding elements in a target check matrix to obtain shift codes E={E1,E2,K,Et-1,Et}, where t is equal to a quantity of rows of the target check matrix, obtaining, by the decoder, t*m groups of LDPC subcodes F1,F2,K,Ftm-1,Ftm according to the shift codes E and a bit length d of the decoder, where Ej is divided into m groups, Ej={(Ej)1d,(Ej)d+12d,K,(Ej)(m-2)d+1(m-1)d,(Ej)(m-1)d+1md}={F(j-1)m+1,F(j-1)m+2,K,Fjm-1,Fjm}, and m=?l/d?, and decoding, by the decoder, the m groups of LDPC subcodes to obtain a decoding result of the LDPC code C.

Abstract: Embodiments of the present disclosure provide an FEC coding and decoding method and device, and a system. A transmit end determines a forward error correction FEC coding type according to a length of to-be-coded data in burst data, and performs coding according to the determined FEC coding type. A receive end determines a forward error correction FEC decoding type according to a length of to-be-decoded data in burst data, and performs decoding according to the determined FEC decoding type. The FEC coding and decoding method provided in the embodiments of the present disclosure improves utilization of a communication resource is improved, and saves a communication resource.

Abstract: A method and an apparatus for determining a time offset are disclosed. The method includes: obtaining, by a device at a head end, a time-domain signal based on a received signal; and then determining a time offset based on values of peak-to-average ratios of a preset quantity of symbols starting from a qth symbol in the time-domain signal, where a peak-to-average ratio of the qth symbol is greater than a preset threshold. A new method for determining a time offset is provided, and takes advantages that the time-domain signal obtained by the device at the head end has stronger capabilities of resisting interference such as frequency offset and phase noise. The method for determining a time offset can be applied both to initial ranging and periodic ranging.

Abstract: A central access network unit comprising a processor configured to assign a plurality of upstream training blocks from an upstream OFDM symbol to a plurality of downstream network units, wherein the OFDM symbol comprises a plurality of pilot subcarriers equally spaced across an upstream RF spectrum in a pre-determined time interval, and wherein each upstream training block comprises a different subset of the pilot subcarriers that are non-consecutive and situated across the upstream RF spectrum, and generate one or more messages comprising assignments of the upstream training blocks, and a transmitter coupled to the processor and configured to transmit the messages to the plurality of downstream network units via a network, wherein the messages instruct at least one of the plurality of downstream network units to transmit a modulated pre-determined sequence at the pilot subcarriers corresponding to the upstream training block assigned to the downstream network unit.

Abstract: Embodiments of the present disclosure provide an FEC coding and decoding method and device, and a system. A transmit end determines a forward error correction FEC coding type according to a length of to-be-coded data in burst data, and performs coding according to the determined FEC coding type. A receive end determines a forward error correction FEC decoding type according to a length of to-be-decoded data in burst data, and performs decoding according to the determined FEC decoding type. The FEC coding and decoding method provided in the embodiments of the present disclosure improves utilization of a communication resource is improved, and saves a communication resource.

Abstract: A decoding method and a decoder for a low-density parity-check (LDPC) code, where the method includes dividing, by a decoder, an LDPC code C whose bit length is n into k LDPC codes D={D1,D2,K, Dk-1, Dk}, arranging, by the decoder, Di, i=1, 2, K, k?1, k by column to obtain transpose codes DT={D1T,D2T,K, Dk-1T, DkT} of the LDPC codes D, performing cyclic shift on DiT, i=1, 2, K, k?1, k by row according to values of corresponding elements in a target check matrix to obtain shift codes E={E1,E2,K,Et-1,Et}, where t is equal to a quantity of rows of the target check matrix, obtaining, by the decoder, t*m groups of LDPC subcodes F1, F2,K, Ftm-1, Ftm according to the shift codes E and a bit length d of the decoder, where Ej is divided into groups, Ej={(Ej)1d,(Ej)d+12d,K,(Ej)(m-2)d+1(m-1)d,(Ej)(m-1)d+1md}={F(j-1)m+1,F(j-1)m+1,K,Fjm-1,Fjm}, and m=?l/d?, and decoding, by the decoder, the m groups of LDPC subcodes to obtain a decoding result of the LDPC code C.

Abstract: A central access network unit comprising a processor configured to assign a plurality of upstream training blocks from an upstream OFDM symbol to a plurality of downstream network units, wherein the OFDM symbol comprises a plurality of pilot subcarriers equally spaced across an upstream RF spectrum in a pre-determined time interval, and wherein each upstream training block comprises a different subset of the pilot subcarriers that are non-consecutive and situated across the upstream RF spectrum, and generate one or more messages comprising assignments of the upstream training blocks, and a transmitter coupled to the processor and configured to transmit the messages to the plurality of downstream network units via a network, wherein the messages instruct at least one of the plurality of downstream network units to transmit a modulated pre-determined sequence at the pilot subcarriers corresponding to the upstream training block assigned to the downstream network unit.

Abstract: Embodiments of the present disclosure provide an FEC coding and decoding method and device, and a system. A transmit end determines a forward error correction FEC coding type according to a length of to-be-coded data in burst data, and performs coding according to the determined FEC coding type. A receive end determines a forward error correction FEC decoding type according to a length of to-be-decoded data in burst data, and performs decoding according to the determined FEC decoding type. The FEC coding and decoding method provided in the embodiments of the present disclosure improves utilization of a communication resource is improved, and saves a communication resource.

Abstract: Provided are a method and an apparatus for canceling interference, to resolve a problem that performance of interference cancellation is poor because accuracy of equalizer coefficients obtained by a CMTS through calculation is not sufficiently high. A specific solution is as follows: (101) A CMTS calculates L equalizer coefficients of an L-tap filter according to a preamble sequence by using an adaptive algorithm, and performs adaptive equalization on a received signal by using the L equalizer coefficients, where L is a positive integer greater than 24; and (102) the CMTS selects K equalizer coefficients from the L equalizer coefficients, and sends a ranging response message carrying the K equalizer coefficients to a cable modem CM, so that the CM performs pre-equalization on a to-be-sent signal according to the received K equalizer coefficients, where K is a positive integer less than or equal to L.

Abstract: The present invention provides a preamble sequence sending and receiving method and apparatus, and a system. The preamble sequence sending method includes: generating, by a transmit end, a frequency offset estimation sequence, where the frequency offset estimation sequence includes N subsequences each with a length of M, N is a positive integer greater than or equal to 2, and M is a positive integer; generating, by the transmit end, a prefix and a suffix based on the frequency offset estimation sequence; adding, by the transmit end, the prefix and the suffix before and after the frequency offset estimation sequence respectively to form a preamble sequence, where the prefix and the suffix are used for canceling multipath interference; and adding, by the transmit end, the preamble sequence to a data packet and sending the data packet to a receive end.

Abstract: An apparatus, comprising a receiver configured to receive a primary signal that comprises a narrowband noise component and a broadband noise component, a processor coupled to the receiver and configured to determine, in a time domain, an estimate of the narrowband noise component in real-time, determine a cancelled output signal in real-time that comprises an estimate of the broadband noise component, and determine an estimate of a power level of the narrowband noise component in real-time.

Abstract: Provided are a method and an apparatus for canceling interference, to resolve a problem that performance of interference cancellation is poor because accuracy of equalizer coefficients obtained by a CMTS through calculation is not sufficiently high. A specific solution is as follows: (101) A CMTS calculates L equalizer coefficients of an L-tap filter according to a preamble sequence by using an adaptive algorithm, and performs adaptive equalization on a received signal by using the L equalizer coefficients, where L is a positive integer greater than 24; and (102) the CMTS selects K equalizer coefficients from the L equalizer coefficients, and sends a ranging response message carrying the K equalizer coefficients to a cable modem CM, so that the CM performs pre-equalization on a to-be-sent signal according to the received K equalizer coefficients, where K is a positive integer less than or equal to L.

Abstract: The present invention provides a preamble sequence sending and receiving method and apparatus, and a system. The preamble sequence sending method includes: generating, by a transmit end, a frequency offset estimation sequence, where the frequency offset estimation sequence includes N subsequences each with a length of M, N is a positive integer greater than or equal to 2, and M is a positive integer; generating, by the transmit end, a prefix and a suffix based on the frequency offset estimation sequence; adding, by the transmit end, the prefix and the suffix before and after the frequency offset estimation sequence respectively to form a preamble sequence, where the prefix and the suffix are used for canceling multipath interference; and adding, by the transmit end, the preamble sequence to a data packet and sending the data packet to a receive end.

Abstract: An apparatus, method, and computer program product are provided for communicating one or more symbols with multiple pilot signals and nulls. In use, one or more symbols are communicated including a plurality of pilot signals and a plurality of nulls, for use in generating a plurality of coefficients.