The Directv Group, Inc.

Hughes Electronics Corporation

Jian Song

Khalid Karimullah

Lin-Nan Lee

Stanley Edward Kay

An approach is provided for supporting transmission in a multi-input-multi-output (MIMO) communication system including a plurality of terminals. A preamble portion of a frame is transmitted by a multiple transmit antennas of a hub using Orthogonal Frequency Division Multiplexing (OFDM) to the terminals over a channel, wherein each of the terminals determines a characteristic of the channel with respect to the transmit antennas as feedback information. The hub receives the feedback information from the terminals. The hub selects, according to the feedback information, a subset of the antennas for transmission of a remaining portion of the frame to the terminal.

Method and system for providing multi-input-multi-output (MIMO) downlink transmission

An approach for electronically performing beam steering is disclosed. For electronic scanning, an n-bit quantized phase shifting approach is employed at each array element of a phased array antenna. By applying an initial phase bias, either deterministically or randomly, in each of the array elements, the performance of a phased array with n-bit quantization (even with n&equals;2) approaches the performance of a system with no quantization. This approach can be used with linearly polarized or circularly polarized waves. For circularly polarized waves, the 2 phase shifts required of n-bit quantization are achieved in a manner that provides a simple, low-loss construction, which allows production of a low-cost reflectarray or a flat-plate lens.

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Germantown, MD, United States of America

Jian Song