BER Performance of ASK-SS and M-ary/ASK-SS Systems Using Compact Matched Filter Bank for an Optical ZCZ Code with Zero-Correlation Zone 4n-2

Abstract

The optical zero-correlation zone (ZCZ) code, which is a set of pairs of binary and biphase sequences with a zero-correlation zone, can provide code division multiple access (CDMA) communication systems without cochannel interference. The M-ary amplitude shift keying spread spectrum (M-ary/ASK-SS) system using this code can detect a desired sequence without interference from undesired sequences. We have proposed the construction of a compact matched filter bank for this code, which is called the compact-type matched filter bank. However, the M-ary/ASK-SS system using this filter bank might have reduced bit error rate (BER) performance because the input-output characteristics of this filter bank for this code with the zero-correlation zone 4n - 2 with positive n are nonlinear. In this paper, we clarify that the BER performance of an M-ary/ASK-SS system using a compact-type matched filter bank over the additive white Gaussian noise (AWGN) and Rayleigh fading channels is not influenced by the nonlinear characteristics of this filter bank, using the theoretical formula of BER characteristics and computer simulation. The BER performance of the ASK-SS system using the compact-type matched filter is reduced compared with that of a system using a direct-type matched filter, as expected. However, the BER performance of the M-ary/ASK-SS system using this compact-type matched filter bank is equal to that of a system using a parallel-type matched filter bank. In fact, this compact-type matched filter bank is effective in the M-ary/ASK-SS system because the BER performance of the M-ary/ASK-SS system is not influenced by the nonlinear characteristics of the compact-type matched filter bank.