Repeatable quasi periodic placement schemes

The problem of placing known symbols in a continuous data stream is considered from an information-theoretic perspective. Given the amount of redundancy associated with known symbols and under the assumptions that the transmit shaping filter is linear and time invariant with a finite impulse response and that the known symbols are placed in clusters of length /spl alpha/ that is greater than or equal to the order of the composite channel, placement schemes that maximize the asymptotic mutual information between the channel input and output are obtained. It is found that these schemes, referred to as repeatable quasi periodic placements, do not depend on the channel coefficients.