Provided are a preamble symbol receiving method and device, characterizing in that the method comprises the following steps: processing a received signal; judging whether the processed signal obtained contains the preamble symbol desired to be received; and if a judgement result is yes, determining the position of the preamble symbol and resolving signalling information carried by the preamble symbol, wherein the received preamble symbol comprises at least one time-domain symbol generated by a transmitting end using a free combination of any number of first three-segment structures and/or second three-segment structures according to a predefined generation rule, the first three-segment structure containing: a time-domain main body signal, a prefix generated based on the entirety or a portion of the time-domain main body signal, and a postfix generated based on the entirety or a portion of a partial time-domain main body signal, and the second three-segment structure containing: the time-domain main body signal, a prefix generated based on the entirety or a portion of the time-domain main body signal, and a hyper prefix generated based on the entirety or a portion of the partial time-domain main body signal.

A communication device including one or more processors configured to perform a radio measurement to obtain a reception metric; identify a potential power reduction from a plurality of power reductions; scale the reception metric to compensate for the potential power reduction to obtain a reduced reception metric; and select a transmit power or a transmit repetition count for a radio frequency transceiver based on the reduced reception metric.

A terminal device registration method and a device, where the method includes sending upstream registration window information to a terminal device, where the upstream registration window information indicates a starting position of an upstream registration window to the terminal device, receiving an upstream access signal sent by the terminal device from the starting position of the upstream registration window, where the upstream access signal includes a correlation sequence symbol and at least one orthogonal frequency division multiplexing (OFDM) symbol following the correlation sequence symbol, the correlation sequence symbol is constituted by a first sequence that meets a preset condition, and the at least one OFDM symbol modulates access information by means of differential phase modulation in a frequency domain, and performing upstream ranging according to the starting position of the upstream registration window and the correlation sequence symbol.

The present invention concerns a method for correcting a frequency shift on symbols received by a receiver, each symbol being composed of N samples and of a cyclic prefix of a predetermined number Δ samples, the Δ samples being a copy of Δ samples of the N samples. The receiver: —calculates for each symbol, a correlation between at most the Δ samples of the cyclic prefix and the at most Δ samples among the last samples, —averages the correlations over a number of symbols and determines one smooth frequency shift estimation for each averaged correlation, —calculates an exponential from the smooth frequency shift estimation, delays the received symbols by a delay, —multiplies the exponential by the delayed received symbols.

This application relates to a sequence detection method and a device. In embodiments of this application, K candidate frequency domain root sequences may be first filtered based on a differentiation result of received first sequence and differentiation results of candidate frequency domain root sequences, and a candidate frequency domain root sequence to which the first sequence actually corresponds only needs to be determined based on the first sequence and the K candidate frequency domain root sequences. For example, there are U candidate frequency domain root sequences. In this case, a current calculation amount is calculation of U*C.sub.s cross correlation values. In embodiments of this application, a calculation amount is calculation of only L*U+K*C.sub.s, where C.sub.s represents a quantity of sampled time domain cyclic shift values, and L represents a quantity of differentiation granularities.

A method for determining a symbol boundary in a data packet belonging to a received OFDM signal is provided. The data packet includes a first training filed and a second training field, which begins with a guard interval. The method includes detecting the beginning of the data packet, and starting an automatic gain control process. The method further includes, after the automatic gain control process is locked, determining autocorrelation peaks and estimating the symbol boundary from times of the autocorrelation peaks.

A receiver for detecting and recovering payload data from a received signal is provided. The receiver includes a detector, a frequency synchronizer, and a demodulator. The receiver is configured to detect the received signal. The received signal includes the payload data and signalling data for use in detecting and recovering the payload data. The frequency synchronizer is configured to process the received signal so as to compensate for a frequency offset in the received signal. The demodulator is configured to detect the one or more first symbols and the one or more second symbols, to recover the signalling data from the one or more first symbols, and to use the signalling data to recover the payload data from the one or more second symbols. The sequence is a signature sequence associated with a transmitter of the received signal.

[Problem] To provide a wireless apparatus, a communication system, and a communication method that enable improvement in reliability by preventing disconnection of communication while enabling high-speed and long-distance transmission. [Solution] A wireless apparatus is configured such that: a correlation calculation unit 501 calculates a correlation coefficient for signals received from respective antennas 207; and a cyclic shift control unit 502 compares the correlation coefficient with a threshold value. If the correlation coefficient is equal to or higher than the threshold value, the cyclic shift control unit determines that there is a direct wave, allocates a common shift amount to a cyclic shift unit 202, and causes a beam forming unit 201 to form and transmit a narrow beam. Meanwhile, if the correlation coefficient is lower than the threshold value, the cyclic shift control unit determines that there is no direct wave, allocates different shift amounts to the cyclic shift unit 202, and causes the cyclic shift unit to diversify the cyclic shift.

Disclosed are a method for acquiring synchronization in a cable network, and a physical (PHY) transmitter and PHY receiver. The method for acquiring synchronization in a cable network according to an embodiment includes receiving, by a PHY receiver, a signal from a PHY transmitter, and acquiring, by the PHY receiver, channel synchronization when a symbol in which a channel preamble exists is detected from the received signal and a position of a frequency in which a channel subcarrier exists is detected from the detected symbol by performing a cross correlation operation on the received signal and the channel preamble.

A method of configuring a preamble of a downlink frame for synchronization in data frame transmission of a 60 GHz a wireless local area network system, the method comprising arranging a short preamble having a plurality of repetitive S symbols, and an IS symbol, and arranging a long preamble having a long cyclic prefix (CP) and a plurality of L symbols for frame synchronization and symbol timing by performing auto-correlation according to the length of window of the auto-correlation.