On transmitter gain/phase imbalance compensation at receiver

This letter explores benefits of compensating transmitter gain and phase imbalances in a receiver for quadrature communication systems. It is assumed that the gain and phase imbalances are introduced at the transmitter only. The Gram-Schmidt orthogonalization procedure is used at the receiver to compensate for the imbalances, Computer simulation has been performed to study a coherent differential QPSK communication system, It has been found that the bit error rate performance is improved significantly if the transmitter phase imbalance is compensated, However, no improvement can be obtained if the transmitter gain imbalance is compensated.