Patent ID: 7023937

Claim:
A receiver for use with a multicarrier modulation communication system having noise conditions comprising: a demodulation module dividing a communication channel into multiple subchannels; an equalizer processing the channel; and at least one window having a window output applied before the equalizer responsive to an observed channel and the noise conditions and adapted to reduce error in the demodulation module output on a selected set of the subchannels where the communication channel has a cyclic prefix and the window ŵ is designed according to the equation: ŵ=R −1 r where: R = E ⁢ ⌊ Y X , t * ⁢ Y X , t T ⌋ r = E ⁡ [ Y X , t * ⁢ d t ] Y X , t T = [ y e , t T ⁡ ( k 0 ) ⋮ y e , t T ⁡ ( k K - 1 ) ] y e , t ⁢ ( k ) = 1 ⁢ N ⁡ [ ( y t ⁡ ( P - W ) - y t ⁡ ( N + P - W ) ) ⁢ ⅇ - j ⁢ 2 ⁢ π N ⁢ k ⁡ ( N - W ) ⋮ ( y t ⁡ ( P - 1 ) - y t ⁡ ( N + P - 1 ) ) ⁢ ⅇ - j ⁢ 2 ⁢ π N ⁢ k ⁡ ( N - 1 ) ] d t = [ H ⁡ ( k 0 ) ⁢ X t ⁡ ( k 0 ) - Y t ⁡ ( k 0 ) ⋮ H ⁡ ( k K - 1 ) ⁢ X t ⁡ ( k K - 1 ) - Y t ⁡ ( k K - 1 ) ] and H(k) is the response of subchannel k, X t (k) is the input to subchannel k for the tth frame of data, Y t (k) is the unwindowed demodulator output for subchannel k for the tth frame of data, y t (n) is the nth received signal from the tth frame of data, N is the number of input symbols, P is the length of the prefix, and W is the length of the window, wherein parameters n, k, t, N, P, and W are integers.