A packet detection method is disclosed. The packet detection method includes the following operations: receiving a wireless communication signal; calculating a delay correlation function of the wireless communication signal; calculating a delay related output value and a threshold value according to the delay correlation function; and determining whether the wireless communication signal satisfies a feature of a wireless network packet or not according to the delay related output value and the threshold value.

Examples described herein include systems and methods which include wireless devices and systems with examples of cross correlation including symbols indicative of radio frequency (RF) energy. An electronic device including a statistic calculator may be configured to calculate a statistic including the cross-correlation of the symbols. The electronic device may include a comparator configured to provide a signal indicative of a presence or absence of a wireless communication signal in the particular portion of the wireless spectrum based on a comparison of the statistic with a threshold. A decoder/precoder may be configured to receive the signal indicative of the presence or absence of the wireless communication signal and to decode the symbols responsive to a signal indicative of the presence of the wireless communication signal. Examples of systems and methods described herein may facilitate the processing of data for wireless communications in a power-efficient and time-efficient manner.

An extensible communication system is described herein. The system includes a first module for receiving a root index value and for generating a constant amplitude zero auto-correlation sequence based on the root value. The system further includes a second module for receiving a seed value and for generating a Pseudo-Noise sequence based on the seed value. The system further includes a third module for modulating the constant amplitude zero auto-correlation sequence by the Pseudo-Noise sequence and for generating a complex sequence. The system further includes a fourth module for translating the complex sequence to a time domain sequence, wherein the fourth module applies a cyclic shift to the time domain sequence to obtain a shifted time domain sequence.

An electronic device having a radio is provided. When the radio boots up, the radio may search for downlink signals transmitted by a wireless base station. The device may generate a narrow set of candidate frequencies over which to search for the downlink signals by leveraging a cyclic prefix autocorrelation property of the downlink signals. Each candidate frequency may have a corresponding center frequency offset (CFO) and symbol boundary timing correction that is used when searching over the narrow set of candidate frequencies. To generate the narrow set of candidate frequencies, control circuitry may generate autocorrelated signals from baseband-shifted input signals over a set of different center frequencies and bandwidths. Searching over the narrow set of candidate frequencies may be significantly faster than performing a full raster scan over all frequencies supported by the radio.

Systems and methods for synchronize word correlation. The methods comprise: obtaining first values that each indicate a likelihood or probability that a respective timeslot in a symbol timing window of a carrier wave is meant or expected to include energy; multiplying, by the correlator, the first values respectively by correlation coefficients to produce a plurality of products (wherein at least one of the correlation coefficients comprises a negative coefficient value); generating a correlation value by combining the products together; determining whether a synchronization word has been detected with a given amount of likelihood based on the correlation value; and causing symbol timing synchronization at a receiver when a determination is made that the synchronization word has been detected with the given amount of likelihood based on the correlation value.

A wireless communication device and method therein for time synchronization in a wireless communication network are disclosed. The wireless communication device determines a first timing (tc) by performing a coarse time synchronization based on a synchronization signal received by the wireless communication device, wherein the received synchronization signal is sampled either in an original sampling rate or a reduced sampling rate. The wireless communication device determines a second timing (tf) by performing a fine time synchronization based on the determined first timing (tc) and the to received synchronization signal.

Detecting physical random access channel (RACH) preambles is accomplished by computing a correlation power profile based on received RACH preambles, where the correlation power profile values may be sorted. A weight factor is computed for each of the correlation power profile values based on a normalized RACH detection threshold. Outlier peaks of the correlation power profile values are selected based on the weight factor. The outlier peaks to the first set of RACH signatures are mapped in order to identify a user equipment (UE) that is associated with one of the received RACH preambles. Network traffic is then controlled for network communications associated with the identified UE.

Techniques are disclosed relating to detection of wireless signals. In some embodiments, a method includes generating an autocorrelation result for a training field in a received wireless message, generating differentiation information based on the autocorrelation result, and determining that one or more signal recognition criteria are met. In some embodiments, the signal recognition criteria include a first criterion that a first peak in the differentiation information satisfies a first threshold for at least a first time interval. In some embodiments, the signal recognition criteria include one or more additional criteria, including a second criterion that a second peak in the differentiation information satisfies a second threshold for at least a second time interval, wherein the first and second peaks have different polarities and/or a third criterion that the first peak corresponds to an autocorrelation result value that is below a particular autocorrelation threshold.

Systems and methods for enabling pre-compensation of timing offsets in OFDM receivers without invalidating channel estimates are described. Timing offset estimations may be sent along with the received OFDM symbols for FFT computation and generating a de-rotated signal output. The timing offset estimation may provide a reference point for dynamic tracking of timing for an OFDM signal and estimated based on an integral value associated with the OFDM signal.

A receiver is configured to detect a plurality of signals on a plurality of subbands over a communication channel that operates on a shared or an unlicensed spectrum. Additionally, the receiver is configured to perform joint correlation over a time domain and a frequency domain of each successive signal of the plurality of signals. Moreover, the receiver is configured to determine a sequence based on the joint correlation. Additionally, the receiver is configured to decode transmission information from the sequence.