Disclosed are a method for multi-user transmission and reception in a wireless communication system and a device for same. More particularly, a method for performing multi-user (MU) transmission by a station (STA) device in a wireless communication system comprises the steps of: generating a high efficiency-long training field (HE-LTF) sequence in a frequency domain in accordance with an MU transmission bandwidth; and transmitting a physical protocol data unit (PPDU) which comprises one or more symbols to which the HE-LTF sequence is mapped, wherein the HE-LTF sequence can be generated by multiplying one row of a P matrix to a length unit of a row of the P matrix in a predetermined sequence.

WTRUs, access points (APs) and methods thereon are disclosed. A method on a WTRU may include receiving a message from an AP that comprises a beamformee capability element; sending a second message to the AP that comprises a beamformer capability element; and receiving, from the AP, a third message in response to the second message that indicates a group to which the WTRU is assigned. The group may be based on the beamformer capability element and the group may indicate UL transmission information to be used by the WTRU. A method on an AP may include determining a group for multiple WTRUs based on a received beamformer capability element. A method on a WTRU may include sending to an AP a message with a low overhead preamble for UL MU-MIMO. The low overhead preamble may include LTFs that enable the AP to distinguish the WTRU from other WTRUs.

A receiver and method applied to the receiver, for estimating a normalized frequency offset value ε between a transmitter and the receiver in a wireless communication system, based on Orthogonal Frequency Division Multiplexing (OFDM), where the method includes receiving a first pilot signal (y.sub.r1) and a second pilot signal (y.sub.r2), from the transmitter, determining a correlation model to be applied based on correlation among involved sub-carrier channels at the y.sub.r1 and the y.sub.r2, computing three complex values μ.sub.−1, μ.sub.0, and μ.sub.1, by a complex extension of a log-likelihood function (λ(ε)), based on the determined correlation model, and estimating the ε by finding a maximum value of a Karhunen-Loeve approximation of the λ(ε), based on the computed three complex values μ.sub.−1, μ.sub.0, and μ.sub.1.

Disclosed are a method for multi-user transmission and reception in a wireless communication system and a device for same. More particularly, a method for performing multi-user (MU) transmission by a station (STA) device in a wireless communication system comprises the steps of: generating a high efficiency-long training field (HE-LTF) sequence in a frequency domain in accordance with an MU transmission bandwidth; and transmitting a physical protocol data unit (PPDU) which comprises one or more symbols to which the HE-LTF sequence is mapped, wherein the HE-LTF sequence can be generated by multiplying one row of a P matrix to a length unit of a row of the P matrix in a predetermined sequence.

A telecommunications receiver is adapted to communicate with mobile devices that operate according to a protocol where the telecommunications receiver operates outside of expected ranges for the protocol but modifies its communications with mobile devices to appear to those mobile devices as being within the expected ranges. To determine what modifications to make to transmissions, the telecommunication receiver processes signals from mobile devices to determine where a communications channel is relative to the expected ranges and uses that information to modify transmissions to mobile devices. The expected ranges might relate to maximum distance between telecommunications receiver and a mobile device, maximum relative velocity, power etc. Determining a relative velocity, and therefore a Doppler shift, can be done by determining a fractional frequency offset, determining an expected subchannel, and determining an integer frequency offset based on the expected subchannel carrier frequency and the measured carrier frequency.

A receiver baseband processor and method for performing preamble detection and Time-of-Arrival, ToA, estimation for a single-tone frequency hopping random access preamble. The processor FFT processes a received signal and identifies logical tones. For each logical tone, the processor reads received symbols; determines a ToA estimate; forms a statistic based on the ToA estimate; compares the statistic to a preamble threshold; and when the statistic is greater than or equal to the threshold, determines a preamble is present and utilizes the ToA estimate for a timing advance command.

This application presents a direct data recovery from subspaces or parameters subranges of a received OFDM signal preidentified as corresponding to specific data symbols, by applying adaptive inverse signal transformation (AIST) method for reversing both original data coding and deterministic and random distortions introduced by a transmission channel, wherein both reversals are achieved by the same conversion of the subspaces or parameter subranges into data transmitted originally in order to eliminate an intermediate recovery of signals or parameters transmitted originally within the received OFDM signal. The AIST includes using both amplitudes and gradients of amplitudes of OFDM tone signals.

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.

A transmitter for transmitting data to communications devices via a wireless access. The transmitter including modulator circuitry configured to receive modulation symbols of a segment and to rotate each modulation symbol by an angle dependent on a choice of modulation scheme, and receive each of the segments of rotated modulation symbols and for each segment to separate real and imaginary components of the rotated modulation symbols for the segment and to interleave the real components of the rotated modulation symbols of the segment differently to the imaginary components of the rotated modulation symbols of the segment. The circuitry also is configured to recombine the real and imaginary interleaved components of the rotated modulation symbols of each segment and to form from the real and imaginary components modulation cells.

A technique for Bluetooth wireless communication is described. According to one aspect of the technique, Bluetooth data from a data source is received in a first wireless device through an antenna and a Bluetooth radio frequency transceiver thereof via a Bluetooth connection with the data source. The Bluetooth data is used to generate a modulation signal according to a narrowband orthogonal multi-carrier modulation technology. The modulation signal is transmitted to a second wireless device through the antenna and the Bluetooth radio frequency. The antenna and the Bluetooth radio frequency transceiver are time-multiplexed by the Bluetooth connection between the first wireless device and the data source, and the wireless connection between the first wireless device and the second wireless device. The described technique can be advantageously used for expanding the distance of Bluetooth wireless propagation of Bluetooth devices.