Patent ID: 7184488
Filing Date: 2007-02-27
Classification: H04B,H04L

Abstract:
1. A method for use in a transmitter adapted to employ four transmit elements to transmit a source bit stream, the method comprising the steps of: dividing said source bit stream into L data substreams, L>2; grouping input derivatives of symbols derived from each of said data substreams to form four input derivative time sequences, one sequence for each transmit element, such that said input derivatives of said symbols are members of the group consisting of: a negative of one of said symbols, a negative of a complex conjugate of one of said symbols, one of said symbols, a symbol developed by encoding at least one sample of at least one of said data substreams, and an unencoded sample of at least one of said data substreams; wherein each of said input derivative time sequences spans L symbol periods and includes at least one input derivative of at least one symbol from each of said L data substreams; and at least one of said input derivatives of said symbols is a complex conjugate of one of said symbols; and grouping output derivatives of said input derivative time sequences to form four transmit time sequences, one sequence for each transmit element, such that said output derivatives of said input derivative time sequences are members of the group consisting of: the input derivative; and a phase-shifted input derivative, where the phase shift is other than 90°, 180°, and 270°; wherein each of said transmit time sequences spans L symbol periods and includes at least one output derivative of at least one symbol from each of said L data substreams; and at least one of said output derivatives of said symbols is a phase-shifted input derivative, where the phase shift is other than 90°, 180°, and 270°.