Interdigital Technology Corporation

Interdigital Patent Holdings, Inc.

Yuejin Huang

Robert L Olesen

Fatih M Ozluturk

Aykut Bultan

Kalpendu Ratanshi Pasad

Jaeyoung Kwak

Eldad M Zeira

Jung-Lin Pan

Chang-Soo Koo

Donald M Grieco

Changsoo Koo

Ariela Zeira

Kyle Jung-Lin Pan

Rui Yang

Elad Zeira

Robert Lind Olesen

The present invention is related to a method and apparatus for implementing space frequency block coding (SFBC) in an orthogonal frequency division multiplexing (OFDM) wireless communication system. A wireless transmit/receive unit (WTRU) including a transceiver and a processor is configured to receive, via the transceiver, an orthogonal frequency division multiplexing (OFDM) signal, wherein the OFDM signal comprises a channel coded data stream that was space frequency block coding (SFBC) encoded such that the SFBC encoding was performed using a plurality of pairs of OFDM sub-carriers. The processor is further configured to decode the OFDM signal.

Method and apparatus for implementing space frequency block coding in an orthogonal frequency division multiplexing wireless communication system

The present invention is related to a method and apparatus for implementing space frequency block coding (SFBC) in an orthogonal frequency division multiplexing (OFDM) wireless communication system. The present invention is applicable to both a closed loop mode and an open loop mode. In the closed loop mode, power loading and eigen-beamforming are performed based on channel state information (CSI). A channel coded data stream is multiplexed into two or more data streams. Power loading is performed based on the CSI on each of the multiplexed data streams. SFBC encoding is performed on the data streams for each of the paired subcarriers. Then, eigen-beamforming is performed based on the CSI to distribute eigenbeams to multiple transmit antennas. The power loading may be performed on two or more SFBC encoding blocks or on each eigenmodes. Additionally, the power loading may be performed across subcarriers or subcarrier groups for weak eigenmodes.

A method and apparatus for implementing space frequency block coding (SFBC) in an orthogonal frequency division multiplexing (OFDM) wireless communication system may be provided. Channel quality information (CQI) may be received, for example, on a per group of OFDM sub-carrier basis. A channel coded data stream may be generated. SFBC encoding may be performed on the channel coded data stream in an open loop mode, for example, such that the SFBC encoding is performed using a plurality of pairs of OFDM sub-carriers. A portion of the channel coded data stream that is SFBC encoded using a pair of OFDM sub-carriers of an OFDM symbol may be SFBC encoded independently of another portion of the channel coded data stream that is SFBC encoded using other pairs of OFDM sub-carriers of the OFDM symbol. The SFBC encoded data may be transmitted over the plurality of OFDM sub-carriers as an OFDM signal.

A wireless transmit/receive unit (WTRU) is configure to receive and sample wireless signals in a shared spectrum where the wireless signal comprise encoded symbols. The WTRU has a channel estimation device configured to process received signal samples to produce an estimate of a channel response of the received signals corresponding to a matrix H. The channel estimation device is preferably configured to process the received signal samples to produce an estimate of noise variance of the received signals. The WTRU preferably has a two stage data estimator that includes a channel equalizer and a despreader. The channel equalizer is configured to process received signal samples using the estimated channel response matrix H and the estimate of noise variance to produce a spread signal estimate of the received signals. The despreader is configured to process the spread signal estimate of the received signals produced by said channel equalizer to recover encoded symbols of the received signals.

Communication system with receivers employing generalized two-stage data estimation

A method and apparatus for performing joint channel equalization (JCE) are disclosed. JCE is implemented to reject inter-cell and intra-cell interference in a receiver. The JCE only requires the channel responses of a desired signal and interferers with respect to different antennas. In order to implement JCE, a number of discrete Fourier transforms (DFTs) and an inverse discrete Fourier transform (IDFT) are performed and a number of independent linear systems are solved. With M antennas, the JCE is capable of completely rejecting M&#x2212;1 interferers. Over-sampling with diversity may be used to increase observation dimensions to a certain extent so that a receiver with M antennas may be able to reject more than M&#x2212;1 interferers.

Method and apparatus for performing joint channel equalization

A method of data estimation for a Time Division Duplex (TDD) Code Division Multiple Access (CDMA) system or any other system using an extended algorithm (EA) in preference to a truncated algorithm (TA). The EA avoids implementation errors by choice of proper extended matrices, and accepts the use of one piece of hardware. The EA also obviates loss of multiple signals in the tail part of each data field, and avoids errors due to transformation of a Toeplitz matrix to a circulant matrix.

Extended algorithm data estimator

The present invention is related to a method and system for optimization of channel estimation and synchronization in an Orthogonal Frequency Division Multiplexing (OFDM) Multiple-Input Multiple-Output (MIMO) wireless communication system. In accordance with the present invention, all of the training sequences are simply constructed based on a basic code by cyclically shifting the basic code. The training sequences are transmitted from different antennas in parallel without performing inverse fast Fourier transform. As a result, there is no peak-to-average ratio problem. Channel estimation is performed in each receiver based on the samples before fast Fourier transform and the maximum-likelihood estimate of channel response in time domain is then mapped into the frequency domain. The channel estimation is not only very simple in implementation, but also very efficient in computation.

Method and system for optimization of channel estimation and synchronization in an OFDM-MIMO wireless communication system

A wireless transmit/receive unit (WTRU) is configure to receive and sample wireless signals in a shared spectrum where the wireless signal comprise encoded symbols. The WTRU has a channel estimation device configured to process received signal samples to produce an estimate of a channel response of the received signals corresponding to a matrix H. The channel estimation device is preferably configured to process the received signal samples to produce an estimate of noise variance of the received signals. The WTRU has a two stage data estimator that includes a channel equalizer and a despreader. The channel equalizer is configured to process received signal samples using the estimated channel response matrix H and the estimate of noise variance to produce a spread signal estimate of the received signals. The despreader is configured to process the spread signal estimate of the received signals produced by said channel equalizer to recover encoded symbols of the received signals.

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Holbrook, NY, United States of America

Yuejin Huang