A novel equalization algorithm for OFDM systems based on Walsh transform

The introduction of a cyclically extended guard interval in OFDM systems turns the traditional time-domain equalization into simple frequency-domain equalization. This is one of the key advantages of the OFDM technique. However, the noise will affect the channel estimation, deteriorating the performance of equalization. Using the Walsh transform, we present a novel algorithm to mitigate the noise effects. The performance of the proposed algorithm is close to that with perfect channel estimation, and the computation required is very small due to the property of the Walsh transform.