Adaptive gain control

Communications and radar receivers of advanced design may utilize real time computers for signal processing. In such instances an adaptive learning scheme can be employed to optimize use of the receiver's dynamic range. An adaptive algorithm for statistically optimum AGC is derived in which the receiver gain is adjusted during the learning process so that the average cost of excluding the received signal from the receiver's dynamic range is minimized. Application of the approach to the frequently occurring situation of Rayleigh distributed signals of unknown strength yields a recursive algorithm which can be easily implemented.