Importance

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Abstract

An improved system and method for communicating information at variable data rates over in-phase (I) and quadrature phase (Q) communication channels in a CDMA spread spectrum communication system is disclosed herein. In an exemplary implementation an input information signal is transmitted over either an I or Q communication channel using a direct sequence spread spectrum communication signal. The information signal is initially divided into first and second subsignals, which are respectively provided to first and second coset-encoding networks. The first coset-encoding combines the first subsignal with a first coset code, while the second coset-encoding network combines the second subsignal with a second coset code orthogonal to the first coset code. In this way the first and second coset-encoding networks are operative to produce first and second coset-encoded signals, respectively. A composite coset-encoded signal formed from the first and second coset-encoded signals is then modulated by an orthogonal function signal to provide a first modulated signal. In-phase pseudorandom noise (PN.sub.I) and quadrature phase pseudorandom noise (PN.sub.Q) signals of predetermined PN codes are used for spreading the first modulated signal for transmission to a receiver over either the I or Q communication channel, respectively. The receiver is operative to produce an estimate of the input information signal on the basis of the modulated carrier signal received over either the I or Q communication channel.

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First Claim