At+t Corp.

At&t Intellectual Property I, L.p.

Mitsubishi Electric Research Laboratories, Inc.

Future Wei Technologies, Inc.

Huawei Technologies Co., Limited

Ye Li

Nelson Ray Sollenberger

Jack Winters

Jinyun Zhang

Justin C Chuang

Lang Lin

Andreas F Molisch

Anthony C K Soong

Jianmin Lu

Nambirajan Seshadri

Philip Orlik

Vahid Tarokh

Yinggang Du

Sirikiat Lek Ariyavisitakul

Huaiyu Zeng

Zhifeng Tao

Leonard Joseph Cimini, Jr

Daqing Gu

Jianxuan Du

Jun Ma

Siritiat Lek Ariyavisitakul

Anthony CK Soong

A wireless multiple-input multiple output (MIMO) communication system includes signaling simulcasting. Base stations include a plurality of transmit antennas and terminals include a plurality of receive antennas to form MIMO channels. In one embodiment, a simulcasting MIMO wireless communication system includes orthogonal frequency division multiplexing (OFDM). This arrangement achieves the spectral efficiency advantages of OFDM and simulcasting.

Simulcasting MIMO communication system

A MIMO OFDM system includes a plurality of space-time encoders for encoding respective data blocks with independent space-time codes. The transformed data block signals are transmitted by a plurality of transmit antennas and received by a plurality of receive antennas. The received data is pre-whitened prior to maximum likelihood detection. In one embodiment, successive interference cancellation can be sued to improve system performance. Channel parameter estimation can be enhanced by weighting the channel impulse response estimates based upon a deviation from average.

MIMO OFDM system

In various embodiments, techniques are provided to determine channel characteristics of various communication systems such as OFDM systems or systems using a plurality of transmit antennas by using various sets of training symbols that produce zero cross-correlation energy. Channel communication can accordingly be simplified as the zero cross-correlation property allows for channel estimation without a matrix inversion.

Channel estimation for wireless systems without matrix inversion

The embodiments of the invention describe method and system for maximizing capacity of a distributed antenna system. A relaying antenna is selected to maximize a signal-to-leakage ratio (SLR) ratio of the distributed antenna system. Further, the capacity of the system is improved by allocating a signal power based on a pseudo-capacity criterion such that an average pseudo capacity of the distributed antenna system is maximized.

Hot-spot wireless access exploiting shadowing diversity of distributed antennas

An improved OFDM receiver is realized by employing a simplified delay function for the transmissions channel. The simplified delay function yields a simplified frequency-domain correlation that is applied to develop an Eigen matrix U that is used in developing estimates of the channels. Those channel estimates are used in the receiver to develop the output signals.

Clustered OFDM with channel estimation

A wireless multiple-input multiple-output (MIMO) communication system includes signal simulcasting. Base stations include a plurality of transmit antennas and terminals include a plurality of receive antennas to form MIMO channels. In one embodiment, a simulcasting MIMO wireless communication system includes orthogonal frequency division multiplexing (OFDM). This arrangement achieves the spectral efficiency advantages of OFDM and simulcasting.

Disclosed herein is a system and method for downlink beamforming that takes into account imperfect channel state information (CSI) at the transmitter when determining the steering vector used in the beamforming process. The steering vector is calculated to increase the ratio of the average power of a desired signal component to the sum of the interference power of other wireless terminals, referred to as the signal-to-leakage ratio. By accounting for imperfect CSI when calculating the steering vector, the bit-error rate for a given signal-to-noise ratio is decreased. Also disclosed is a power allocation method that improves performance of the system by increasing the signal-to-interference-plus-noise ratio for all of the wireless terminals currently communicating with the base station. The power allocation similarly decreases the bit-error rate for a given signal-to-noise ratio, especially at high signal-to-noise ratios.

Beamforming with imperfect channel state information

Cross-talk is canceled in a cooperative wireless relay network that includes a base station (BS), a relay station (RS), and a mobile station (MS). A coupling channel between a transmit antenna and a receive antenna colocated at the RS is estimated. Cross-talk interference determination is based on a previous transmitted signal by the transmit antenna, and the coupling channel. The cross-talk interference is subtracted from a currently received signal by the receive antenna to obtain a residual signal. The residual signal is then transmitted as a next transmitted signal by the transmit antenna.

Cross-talk cancellation in cooperative wireless relay networks

A telecommunication network component, comprising: a memory configured to store instructions, and a processor configured to execute the stored instructions, the instructions comprising: determining a plurality of power allocation adjustments for signals transmitted via an antenna array that promotes decision-feedback detection without using channel state information, and outputting the power allocation adjustments to the array. Also disclosed is a power allocation method comprising: determining a power allocation scheme that promotes decision-feedback detection in a multiple-input and multiple-output system without using channel state information, and implementing the power allocation scheme on an antenna array by modifying an adjustment for each of a plurality of antennas in the array.

Power allocation in a MIMO system without channel state information feedback

A method for decoding a received signal comprising the steps of receiving a signal at a plurality of antennas, applying Fast Fourier transformations to the received signal, estimating channel characteristics of a channel over which the signal was transmitted using iterative processing and decoding the transformed signal.

Near optimal joint channel estimation and data detection for COFDM systems

In various embodiments, techniques are provided to determine channel characteristics of various communication systems such as OFDM systems or systems using a plurality of transmit antennas by using various sets of training symbols.

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Marietta, GA, United States of America

Ye Li