Impulsive Noise Reduction in Data Communication Systems Employing Smear/Desmear Technique

Abstract

In the proposed system, two complemen­ tary delay Smear/Desmear (S/D) filters were used in the transmitter and receiver sides respectively. A complete analysis was carried out to show that for optimum reduction of impulsive noise, 32 taps tran­ sversal filters should be used. The S/D filters were designed using bucket brigade devices (BBD) type TAD-32. Laboratory tests were carried out on the system using random input data of 880 b/see., while the system is subjected to random impulsive noise, a model of which was designed. A reduction in the probability of error (Pe) by a factor of 25 was obtained over conventional system (without S/D filters) at (SNR) of 7 dB. This reduction factor is increased to 50 when clipper was used prior to the desmear filter at the receiver side. Also (SNR) im­ provement of about 14 dB was obtained at Pe = 10~^.