Patent ID: 7609615
Filing Date: 2009-10-27
Classification: H04L

Abstract:
1. A method of performing channel compensation and symbol demodulation on a received signal in an Orthogonal Frequency Division Multiplexing (OFDM) system, the method comprising: generating a channel-compensated signal by multiplying a fast Fourier transform (FFT) received signal by an estimated channel impulse response; calculating the power of the estimated channel impulse response; and setting the power of the estimated channel impulse response as a reference point value defining a minimum distance between signal points in a signal constellation used for modulation of the FFT received signal, and deciding soft metric values for channel decoding of the channel-compensated signal using the reference point value, I-channel and Q-channel signal components of the channel-compensated signal, and a multiple of the reference point value corresponding to the distance of a signal point closest to the origin to each axis in the signal constellation, wherein 16-ary Quadrature Amplitude Modulation (16QAM) is used and the channel-compensated signal modulates the deciding of soft metric values which comprises deciding soft metric values for the channel-compensated signal by where Y