AGC output characteristics in broadband mobile communication systems

At present, there are increasing demands for transmission and reception of multimedia information, and various broadband communication systems are being considered in order to respond to these requests. In these systems, frequency-selective fading due to the delayed wave is one of the most important problems. One of the properties of the frequency-selective fading environment is the phenomenon that the received power depends on the transmitted data pattern. Thus, there can arise a problem that the AGC output deviates from the reference value when there is a difference of patterns between the data part and the AGC part. This paper investigates the relation between the transmitted pattern and the received power distribution in the frequency-selective fading environment, and calculates the probability distribution under the condition that there is no fading fluctuation. Then, the AGC output characteristics are examined by computer simulation for the case in which there is a pattern difference between the data part and the AGC part. It is shown that the output distribution greatly depends on the selection of the pattern in ordinary environments in broadband mobile communication.