A method in a receiver includes receiving from a transmitter a signal including at least first and second frames that carry same data. First and second data symbols are identified in the respective first and second frames, wherein the first symbol has a same data value as the second data symbol. A frequency offset between the transmitter and the receiver is estimated based at least on the identified first and second data symbols. A frequency of the receiver is adjusted based on the estimated frequency offset.

Embodiments disclose an automatic gain control method and a communications device in a wireless local area network. The method includes generating a physical layer packet, where the physical layer packet includes a high efficiency long training field, the high efficiency long training field includes N symbols, a length of a cyclic prefix (CP.sub.— of a first symbol in the N symbols is greater than or equal to a minimum length required by a receiver device to perform automatic gain control (AGC) estimation, and N is a positive integer. The method also includes sending the physical layer packet to the receiver device.

Provided are a method and device for determining a sequence group and a method and device for determining a cyclic shift. The method includes: determining a symbol index of a first specified orthogonal frequency division multiplexing (OFDM) symbol in a scheduling unit; and determining a sequence group or cyclic shift used by a channel or a signal according to the symbol index.

A transmitter transmits payload data using Orthogonal Frequency Division Multiplexed (OFDM) symbols. The transmitter comprises a frame builder configured to receive the payload data to be transmitted and to receive first signalling data for use in detecting and recovering the payload data at a receiver, and to form the payload data and the first signalling data into frames for transmission, the first signalling data forming a part of the frames with the payload data. A modulator is configured to modulate a first OFDM symbol with the first signalling data and to modulate one or more second OFDM symbols with the payload data. A signature sequence processor provides a signature sequence, a combiner combines the signature sequence with the first OFDM symbol, and a transmission unit transmits the first and second OFDM symbols. The signature sequence provided by the signature sequence processor comprises at least one of a first synchronization sequence or a second message sequence, the first synchronization sequence and/or the second message sequence being combined by the combiner with the first OFMD symbol. The first synchronization sequence is provided for a receiver to detect and to recover the first signalling data from the first OFDM symbol and the second message sequence provides message information to the receiver. The message information may be used to convey a specific message to a user such as an emergency warning relating to a natural disaster such as an earthquake or a tsunami warning.

In an embodiment, an apparatus includes a buffer to store incoming orthogonal frequency division multiplexed (OFDM) samples. This buffer is configured to output the OFDM samples according to a read pointer that can be adjusted by a sum value corresponding to a sum of a length of a symbol and a feedback value, to align the read pointer with the symbol. In addition, the apparatus further includes a feedback circuit coupled to the buffer to receive the output OFDM samples and generate the feedback value based at least in part on the output OFDM samples.

One embodiment provides an apparatus. The apparatus includes an optimization module configured to determine a guard interval remainder based, at least in part on a comparison of an allowable microreflection interference level and an actual microreflection interference level; and a windowing module configured to window an OFDM (orthogonal frequency division multiplexed) symbol utilizing the guard interval remainder. The apparatus may further include a channel estimator module configured to determine a predicted channel frequency response based, at least in part, on a probing symbol; and a pre-equalizer module configured to pre-equalize the OFDM symbol based, at least in part, on the predicted channel frequency response.

A method for scheduling resources in a network where the scheduling activity is split across two nodes in the network is disclosed, comprising: receiving, from a local scheduler in a first radio access network, access network information at a global scheduler; accessing information regarding a second radio access network allocating, at the global scheduler, resources for secondary allocation by the local scheduler; applying a hash function to map the allocated resources for secondary allocation to a set of hash values; and sending, from the global scheduler, the set of hash values to the local scheduler.

In many wireless communication systems, there is a major problem with the coverage in indoor environments because of signal loss during signal penetration through walls and other structures. Femto cells or repeaters may be used to address the signal coverage issue for indoor environments. The cost of femto cells or repeaters may be high depending on its capabilities. Method and apparatus are disclosed for a Signal Enhancer with reduced complexity to enhance the signal for an OFDM based TDD wireless communication system. This may result in a lower cost solution for improving the coverage and the overall communication system performance.

[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.

This application relates to a communication method and apparatus, and may be applied to the internet of vehicles, for example, V2X, LTE-V, and V2V, or may be used in fields such as intelligent driving and intelligent connected vehicles. A first resource is determined in a first resource set, and a jth synchronization signal block in N synchronization signal blocks is sent on a jth candidate resource in N candidate resources. The first resource set includes M groups, and an ith group in the M groups includes X candidate resources. M×X candidate resources included in the first resource set may be used to transmit a synchronization signal block. Each of the N synchronization signal blocks occupies Y symbols in time domain, where Y is an integer greater than or equal to 5. The first resource includes the N candidate resources, and the N candidate resources belong to one or more groups in the M groups.