A symbol boundary detection method includes: calculating desired signal power according to a receiving signal by a receiver device; calculating interference power according to the receiving signal by the receiver device; calculating a signal-to-interference power ratio according to the desired signal power and the interference power by the receiver device; finding a best signal-to-interference power ratio to determine a reference symbol boundary time by the receiver device; and processing the receiving signal according to the reference symbol boundary time by the receiver device for a subsequent demodulation process performed by a demodulator circuit.

Methods, systems, and devices for wireless communication are described. A base station may broadcast a synchronization signal using a narrowband portion of a bandwidth of a cell. The synchronization signal may include a sequence repeated over several symbol periods using a cover code to support power-efficient cell acquisition. A user equipment (UE) receiving the synchronization signal may determine frequency and timing information for a cell by performing a weighted combination and accumulation of low complexity autocorrelation and cross-correlation procedures on the synchronization signal. The reduced complexity correlation procedures may be enabled based on the use of the cover code and a base sequence. In some cases, the cross-correlation may be performed at multiple sampling rates. The use of the cover code within the synchronization signal may also support correlation procedures that use recursive or repeated updates, which may allow for further reduced computational complexity relative to other cell search procedures.

This disclosure presents distributed and decentralized synchronization for wireless transceivers. The disclosed system, device, and method achieve sub-nanosecond synchronization using low-cost commercial off the shelf software defined radios. By providing a decentralized mechanism that does not rely on a hierarchical master-slave structure, networks constructed as disclosed are robust to sensor drop-out in contested or harsh environments. Such networks may be used to create phased array radars and communication systems without requiring wired connections to distribute a common clock or local oscillator reference.

The present disclosure provides a method for estimating timing and/or frequency of a wireless signal; the method including the steps: receiving a digitally modulated signal; extracting a plurality of signal samples associated with a short training field (STF) of a PHY protocol data unit (PPDU) of an 802.11 frame; performing correlation operations on the plurality of signal samples to generate a predetermined number of correlation peaks; comparing the generated correlation peaks with a variable dynamic threshold; and calculating timing and/or frequency of the digitally modulated signal using the outcome of the comparing step.

A receiving device 100 includes a reception unit 10, a delay signal generation unit 22, a difference calculation unit 23 that calculates a phase difference between the received signal and the delay signal, a variance calculation unit 24 that calculates a variance of the phase difference within a plurality of calculation sections while sliding a set of the plurality of calculation sections which are set corresponding to a cyclic prefix group assigned to a predetermined symbol group included in the received signal, together on the time axis, a symbol detecting unit 25 that detects a position of a symbol in the symbol group on the time axis, based on the position of the minimum peak of the variance on the time axis, and a synchronization timing signal generation unit 29 that generates a synchronization timing signal, based on information on the position of the symbol on the time axis.

This application provides a random access method and an apparatus. The method includes: receiving, by a terminal device, a broadcast signal; and sending, by the terminal device, a random access signal, where a preamble sequence in the random access signal includes K first symbols and Q second symbols, the first symbol and the second symbol are different from each other, K and Q are integers greater than or equal to 1, K+Q=N.sub.SEQ, and N.sub.SEQ is a quantity of symbols included in the preamble sequence.

Provided are a preamble symbol generation method and receiving method, and a relevant frequency-domain symbol generation method and a relevant device, characterized in that the method comprises: generating a cyclic prefix according to a partial time-domain main body signal truncated from a time-domain main body signal; generating a modulation signal based on a portion or the entirety of the partial time-domain main body signal; and generating time-domain symbols based on at least one of the cyclic prefix, the time-domain main body signal and the modulation signal, wherein the preamble symbol contains at least one of the time-domain symbols. Therefore, using the entirety or a portion of a certain length of a time-domain main body signal as a prefix, it is possible to implement coherent detection, which solves the issues of performance degradation with non-coherent detection and differential decoding failure under complex frequency selective fading channels; and generating a modulation signal as a postfix based on the entirety or a portion of the above truncated time-domain main body signal enables the generated preamble symbol to have sound fractional frequency offset estimation performance and timing synchronization performance.

The present disclosure relates to a pre-5.sup.th-Generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4.sup.th-Generation (4G) communication system such as long-term evolution (LTE). Methods and devices are provided for detecting a synchronized primary synchronization signal (PSS) sequence in a wireless network is provided. A device receives a synchronization signal including a PSS sequence. The device determines a plurality of peak correlation values by correlating a plurality of predefined PSS sequences with time-shifted variants of the received synchronization signal. The device detects the synchronized PSS sequence from the plurality of predefined PSS sequences by analyzing the plurality of peak correlation values using at least one of probability detection values, a sliding window method, weight assignments, and a rewarding-based method.

A synchronisation symbol detector that comprises two correlation modules and a comparison module. The first correlation module performs one or more correlations between the input signal and a down-converted version of the input signal and generates a first correlation metric from the one or more first correlations. The second correlation module performs one or more second correlations between the input signal and an up-converted version of the input signal and generates a second correlation metric from the one or more second correlations. The comparison module is configured to compare the first correlation metric and the second correlation metric and determine whether the input signal comprises a synchronisation symbol based on the comparison.

The present disclosure includes a method of performing synchronization and frequency offset estimation The method includes an input signal corresponding to a single received training sequence. Phase information and a phase index are generated by performing an auto-correlation function (ACF) on the input signal. A templet signal associated with a sample index of the input signal is generated based on at least one pre-stored look-up table (LUT), the phase index, a frequency bandwidth of the input signal, and the sample index. Power associated with the sample index is calculated by performing a matched filtering on the input signal based on the templet signal. A synchronization timing and a frequency offset for the input signal are simultaneously determined based on a result of the matched filtering.