US Patent 7324428 Frame identifier

Method and system for determining the number of one or more of a sequence of M+1 consecutive OFDM frames from analysis of the designated preambles of two or more consecutive frames (m=0, 1, . . . , M; M≧1). An overlap function OF(m;k) is formed for each frame with a sequence of selected reference signals indexed by k (k=1, 2, . . . , K), dependent upon the frame number m and the index k, and a phase (sequence location corresponding to largest amplitude of overlap function) is determined. An Mth-order phase difference is computed that corresponds to frame number of one of the M+1 frames. A consistency check is provided for the phase numbers.