Construction of ZCZ Codes with Low Aperiodic Autocorrelation

• Published in: Journal of Signal Processing Vol. 16; no. 6; pp. 477 - 485
• Main Authors: Hayashida, Tomohiro, Matsufuji, Shinya, Matsumoto, Takahiro, Fan, Pingzhi
• Format: Journal Article
• Language: English
• Published: Tokyo Research Institute of Signal Processing, Japan 2012; Japan Science and Technology Agency
• Subjects: CDMA; code generator; matched filter bank; signal design; spreading code
• ISSN: 1342-6230; 1880-1013
• DOI: 10.2299/jsp.16.477

ZCZ-CDMA, which is a quasi-synchronous CDMA (code division multiple access) system using a set of sequences with a zero correlation zone called ZCZ code as a spreading code, is useful for short-range wireless communications because of its excellent properties such as co-channel interference-free performance and fast frame synchronization capability. In this paper, we propose a ZCZ code with good aperiodic autocorrelation to be used as a synchronization symbol and training signal for channel estimation. The ZCZ-code is derived from an even-shift orthogonal sequence called an E-sequence, whose out-of-phase aperiodic autocorrelation function takes a value of zero at any even shift. A ZCZ code of length 2n is discussed expressed by both a logic function and matrices including the Sylvester type Hadamard matrix. The logic function gives a code generator consisting of 2n counters, and feedforward logic, and the matrices provide a matched filter bank that can take the correlation between input signals and any sequence in, the ZCZ code simultaneously.