Automatic gain control in high adjacent channel interference for OFDM systems

In wireless communication systems, the received signal power is highly fluctuated by changing of distance between transmitter and receiver, and by mobility of the receiver. Most of automatic gain controller (AGC) algorithms are developed to make the constant power of received signal. But in high adjacent channel interference (ACI) environment, the conventional algorithms do not work well. The proposed algorithm utilizes a gain splitting on variable gain amplifier (VGA) and fast Fourier transform (FFT) to enhance the receiver demodulation performance in high ACI environment. The proposed algorithm has better bit error rate (BER) performance than the conventional algorithm.