Adaptive compensation of gain/phase imbalances and DC-offsets using constant modulus algorithm [transceiver applications]

A novel technique, based on the constant modulus algorithm (CMA) is proposed to compensate the gain/phase imbalances and DC-offsets in a transceiver. The algorithm is first described when implemented in the transmitter, to compensate for its circuit distortions. It is shown that the gain/phase imbalances and DC-offsets of the modulator can be corrected even in the presence of a high noise level. The symbol error rate (SER) performance approaches that of a system without imperfections. In the second approach, the CMA algorithm is implemented at the receiver to compensate for the receiver distortions and also the transmitter ones. It is shown that the algorithm compensates for most of the receiver distortions and partly the transmitter ones.