E.I. Krengel

Binary sequences with zero correlation zone (ZCZ) are widely used in quasi-synchronous code division multiple access (QS-CDMA) and radar systems to reduce co-channel and multi-path interference. ZCZ sequences possess zero out-of-phase autocor-relation and zero cross-correlation values simultaneously at a local zone |τ|  D around zero shift. In the paper, we construct two new families of binary ZCZ sequences with mismatched filtering. It is known that mismatched filtering provides zero out-of-phase values of a periodic correlation at receiving filter output at the expense of slightly reduced signal-to-noise ratio (SNR) with respect to matched filtering. Here, we shall use mismatched filtering for the constructing of new binary ZCZ sequence pairs. A sequence is called perfect if all its out-of-phase autocorrelation coefficients are zero, a sequence is called almost-perfect if all its out-of-phase autocorrelation coefficients except one (at shift N/2) are 0. The first family is derived from pairs of almost-perfect sequences (APT) of length 4(pmk1)/(pm1) and 2(pmk1)/(pm1), (pm1)0 mod 4. The second family is derived from pairs of the Ipatov perfect sequence of length (pmk1)/(pm1) and the APT sequence of length 4(pmk1)/(pm1), odd k and (pm1)0 mod 4. These sequences have energy efficiency close to 1 and a maximum of length of their ZCZ in 1.5 times exceeds the bound for binary ZCZ sequences. Also it is shown that the obtained ZCZ gain satisfies the theoretical bounds of the periodic binary ZCZ sequences with mismatched filtering found by D.Peng, P. Fan, and X.Tang. Some examples of new binary ZCZ se-quences with mismatched filtering are presented.