Patent attributes
A radio transceiver comprises a spreader that spreads a plurality N of data symbols with a set of N complex-valued orthogonal spreading codes to produce N spread symbols. The spreading codes comprise rows or columns of a Discrete Fourier Transform (DFT) matrix. A mapper maps each of the N spread symbols to one of a set of Orthogonal Frequency Division Multiplexing (OFDM) subcarriers. A modulator modulates the N spread symbols onto the set of OFDM subcarriers to generate a discrete-time OFDM transmission signal. The spreading reduces the discrete-time OFDM transmission signal's peak to average power. The radio transceiver transmits the discrete-time OFDM transmission signal to a receiver that de-modulates and de-spreads the plurality N of data symbols.