Patent attributes
An improvement to multi-carrier communication, such as an OFDM and MC-CDMA system, where in a multipath or phase distorted channel, the received signal is flat with respect to frequency and linear with respect to phase. A first unit transmits a plurality of multi-carrier signals, which include unmodulated carrier signals. A second unit receives the plurality of multi-carrier signals, and determines the in-phase and quadrature amplitudes or powers of the unmodulated carrier signals of the received multi-carrier signal. The second unit compares the measured in-phase and quadrature amplitudes or powers of the unmodulated carrier signals to predetermined criteria, and generates adjusting data from the compared in-phase and quadrature amplitudes or powers. The first unit uses the adjusting data to pre-distort the next plurality of multi-carrier signals to be transmitted, the in-phase and quadrature amplitudes or powers of the plurality of multi-carrier signals. The first unit transmits, with the in-phase and quadrature phase adjusted per the adjusting data, the next plurality of multi-carrier signals, through the communications channel.
