A method of frequency search and error correction of clock and data recovery circuit, comprising: initializing a frequency search algorithm parameter; processing a frequency error parameter UP/DN signals according to the set algorithm parameter and starting the frequency search, in which, the algorithm accordingly counts the UP/DN signals. When a phase error signal transition occurs, a transition parameter JUMP is accumulated by 1, and an accumulation parameter SUM is obtained and is further judged that whether a frequency search result is to be output. Number of repeating times of verification and threshold parameters are set, accordingly a reset DCRL value is obtained to verifies a frequency locking result and outputs the result. The present invention improves accuracy of UP/DN pulse counting, increases stability and reliability of the frequency locking, avoids a false locking in the frequency locking, and prevents an excessive locking time in the frequency locking, overcomes error judgment of the frequency search caused by a random jitter, and correctly completes the frequency search and locking, avoids failure of the CDR caused by an error frequency locking.

A radio receiver device determines whether a digital radio signal includes a predetermined cyclic preamble. An input portion samples the digital radio signal and generates a plurality of samples for storage in a buffer. A first autocorrelator correlates first and second subsets of the samples to generate a first correlation metric, the second subset having been stored in the buffer earlier than said first subset by an even integer multiple of half of the preamble period. A second autocorrelator correlates first and third subsets of the plurality of samples to generate a second correlation metric, the third subset having been stored in the buffer earlier than said first subset by an odd integer multiple of half of the preamble period. A processing portion calculates a difference between the correlation metrics and determines that the radio signal includes the predetermined cyclic preamble when the difference is greater than a threshold value.

A communication device includes: a plurality of wireless communication sections, each of which is configured to wirelessly receive a signal from another communication device; and a control section configured to select a wireless communication section from which a specific reception time corresponding to an optimum parameter that is a reliability parameter indicating that the specific reception time is most appropriate for a processing target is detected, as a transmission communication section serving as a wireless communication section that transmits a signal from among the plurality of wireless communication sections, and configured to measure a distance between the transmission communication section and the other communication device on the basis of the specific reception time detected from a correlation computation result obtained from signals transmitted/received between the other communication device and the selected transmission communication section.

An optical transceiver includes an optical transmitter transmit an optical signal; an optical receiver to extract a monitoring control signal from an optical signal, the monitoring control signal including first and second frames having the respective headers, and being separated in time; and a processing part to generate a bit stream from the monitoring control signal; generate a first byte stream from the bit stream; extract monitoring control data from a byte stream subsequent to the first byte stream, if the first byte stream is equal to the first header; generate a second byte stream from the bit stream if the first byte stream is different from the first header, the second byte stream having the same length as the second header; and extract the monitoring control data from a byte stream subsequent to the second byte stream if the second byte stream is equal to the second header.

Communication systems and methods in accordance with various embodiments of the invention utilize modulation on zeros. Carrier frequency offsets (CFO) can result in an unknown rotation of all zeros of a received signal's z-transform. Therefore, a binary MOCZ scheme (BMOCZ) can be utilized in which the modulated binary data is encoded using a cycling register code (e.g. CPC or ACPC), enabling receivers to determine cyclic shifts in the BMOCZ symbol resulting from a CFO. Receivers in accordance with several embodiments of the invention include decoders capable of decoding information bits from received discrete-time baseband signals by: estimating a timing offset for the received signal; determining a plurality of zeros of a z-transform of the received symbol; identifying zeros from. the plurality of zeros that encode received bits by correcting fractional rotations resulting from the CFO; and decoding information bits based upon the received bits using a cycling register code.

A Bluetooth receiver has an RF front end which has a gain control input, the RF front end converting wireless packets into a baseband signal which is coupled to the input of an analog to digital converter (ADC). A clock generator provides a clock coupled to the ADC, and an AGC processor performs an AGC process to provide a gain which places the baseband symbols in a range that is less than 90% of the input dynamic range of the ADC. When in a connected state, the clock generator provides a clock which is slower than is required to complete the AGC process during a preamble interval, and the AGC process uses a few initial bits of the address field. The remaining bits of the address field is compared with the corresponding address bits of the receiver to determine whether to receive the packet.

A method of auto-aligning a beam within a receiving electronically steered antenna system comprising a plurality of antenna elements is provided. The method comprises the steps of: providing a list of codes, wherein each code is embedded in signals transmitted by a respective transmitting entity, and identifies the transmitted signal as originating from said transmitting entity; selecting a transmitter and identifying a corresponding code for that transmitter; and for each antenna element: receiving a first communications signal; receiving a second signal representative of first communications signals received by each of the plurality of antenna elements; correlating the first and second signals with the identified code to generate first and second output signals; comparing the first and second output signals and determining a phase shift and/or time delay for minimizing the difference between the first and second output signals; and applying the phase shift and/or time delay to the first received communication signal.

Provided is a wireless audio synchronization method, a wireless audio playback device and a wireless audio transceiving system. The method includes sampling based on a first local clock signal of the wireless audio playback device a received wireless signal; determining a peak moment corresponding to a current wireless data packet; counting based on the first local clock signal a time difference between peak moments corresponding to the current and previous wireless data packets and adjusting a clock cycle of the first local clock signal based on a counting result so that the counting result approaches a predetermined count value; and playing after a predetermined number of clock cycles of the first local clock signal the data segment or its preset part according to a second local clock signal of the wireless audio playback device, where there is a fixed frequency multiple relationship between the first and second local clock signals.

A method includes calculating first correlation values corresponding to a first symbol duration based on input samples, the input samples being generated from a received signal; calculating phase differences respectively corresponding to the input samples based on the first correlation values and second correlation values corresponding to a second symbol duration preceding the first symbol duration; updating accumulative phase differences respectively corresponding to the input samples based on the phase differences; and detecting a symbol boundary based on the updated accumulative phase differences.

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.