Abstract
We analyze the system performance of optical heterodyne CPFSK receivers with AFC loops. The effects of closed loop gain and postdetection filters are taken into account. The GQR (Gaussian quadrature rule) method is used to deal with the laser phase noise characteristics in computing the bit-error rates. The impact of closed loop gain on the system performance is investigated. The optimum design of postdetection filters is outlined in showing the improvement of system performance compared with the system without AFC.