Interdigital Technology Corporation

Elbit Systems of America, LLC

Innovative Concepts Inc.

Qingyuan Dai

Robert L Olesen

Chang-Soo Koo

I-Tai Lu

Peter J Voltz

Yongwen E Yang

Eldad M Zeira

KunJu Tsai

Charles Woloszynski

Gregory N Smith

Hui-Yuan Teng

Kunjun Tsai

Charles H Woloszynski

A method and apparatus for implementing spatial processing with unequal modulation and coding schemes (MCSs) or stream-dependent MCSs are disclosed. Input data may be parsed into a plurality of data streams, and spatial processing is performed on the data streams to generate a plurality of spatial streams. An MCS for each data stream is selected independently. The spatial streams are transmitted via multiple transmit antennas. At least one of the techniques of space time block coding (STBC), space frequency block coding (SFBC), quasi-orthogonal Alamouti coding, time reversed space time block coding, linear spatial processing and cyclic delay diversity (CDD) may be performed on the data/spatial streams. An antennal mapping matrix may then be applied to the spatial streams. The spatial streams are transmitted via multiple transmit antennas. The MCS for each data stream may be determined based on a signal-to-noise ratio of each spatial stream associated with the data stream.

Method and apparatus for implementing space time processing with unequal modulation and coding schemes

Method and apparatus for implementing space time processing

A method including receiving at a synchronizing node a first reference frame from a first reference node at a first time and storing a first time value representing the first time, and calculating a timing estimator by subtracting a minimum time value, representing the distance from the synchronizing node to the first reference node, from the first time value. The method includes receiving at the synchronizing node a second reference frame at a second time and transmitting from the synchronizing node to the first reference node a short timing contention time frame. The method includes receiving at the synchronizing node from the first reference node an arrival time value representing the time at which the first reference node received the short timing contention frame and calculating a time drift from the first arrival time value and the second time value and adjusting the timing estimator based on the time drift.

MIMO slotted aloha (MSA) system

A communications system includes one or more antennas and a receiver coupled to the one or more antennas. The one or more antennas are operable to receive a signal transmitted from a transmitter. The receiver includes a combiner that is operable to combine the signals received by the one or more antennas into a combined signal. The signal received by the receiver is a single-carrier waveform comprising a signal field and one or more data fields after the signal field. The signal field indicates a modulation technique of the one or more data fields. The one or more data fields include a first short unique word, a data payload after the second short unique word, and a second short unique word after the data payload.

Single carrier waveform system with frequency domain equalization

In an orthogonal frequency division multiplexed (OFDM) multiple-in multiple-out (MIMO) wireless communication system, a method for correcting sampler clock frequency offset in a receiver comprises acquiring the frequency offset and symbol timing in a received signal by the receiver. The estimated value of a fractional offset is computed, and a correction in the frequency domain based upon the estimated value of the fractional offset is performed.

Method and apparatus for correcting sampler clock frequency offset in OFDM MIMO systems

In a wireless communication system, a method and apparatus for noise estimation of a received OFDM communication signal, wherein the signal comprises a data frame with a preamble having at least one long training field (LTF) containing two substantially similar OFDM symbols, comprise examining the LTF for substantially similar OFDM symbols. The noise power in the signal is estimated and the received signal power is measured. The signal to noise ratio is calculated and the signal power is determined by subtracting the noise power from the signal noise.

Method and apparatus for estimating signal-to-noise ratio, noise power, and signal power

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Qingyuan Dai