Analysis and Design of an Optimal Noise Estimation and Cancellation Filter in Wireline Communication

This paper presents a comprehensive study of noise prediction and cancellation techniques in high-speed wireline communication systems. Feedforward and feedback architectures are compared, and it is found that while feedforward architecture can reduce total noise power, it fails to reduce symbol error rate (SER) due to unreliable noise estimation. To address this issue, an optimal noise estimation and cancellation filter (ONECF) is proposed, which directly minimizes SER. The paper provides mathematical analysis and experimental results of ONECF, demonstrating that ONECF is effective in reducing SER and improving SNR, and the degree of improvement is proportional to the channel loss. However, ONECF’s performance saturates at a certain level, which depends on the number of taps used. We conclude that feedforward noise cancelling filters are suitable for low to medium loss channels, whereas feedback ones are suitable for high loss channels.