Patent ID: 7929930
Filing Date: 2011-04-19
Classification: H04B

Abstract:
1. A system for transmitting data at a maximum ratio in a Broadband Wireless Access (BWA) communication system, comprising: a Base Station (BS) for transmitting a signal directed to a user terminal to a Relay Station (RS) in a first time slot; the RS for transmitting a signal received from the BS to the user terminal in a second time slot; and the user terminal for receiving the signal received from the RS, wherein if two RSs are used, and the RSs operate in an Amplify and Forward (AF) mode and use Maximum Ratio Transmission (MRT), a first RS of the two RSs transmits a signal expressed as the following equation to the user terminal, where p denotes a transmit power, n 1 denotes Additive White Gaussian Noise (AWGN), h 1 denotes a channel gain between the BS and the first RS, h 2 denotes a channel gain between the second RS and the BS, h 3 denotes a channel gain between the first RS and the user terminal, h 4 denotes a channel gain between the second RS and the user terminal, h* 3 denotes a conjugate complex value of a channel gain between the first RS and the user terminal, h* 1 denotes a conjugate complex value of a channel gain between the BS and the first RS, x denotes a transmitted modulation symbol, r 3 denotes a signal transmitted by the first RS, and r 1 denotes a signal received from the BS at the first RS.