Low-Complexity Implementation of PN Correlator for Wireless Transmission Systems

Pseudo-noise (PN) sequence is widely used in wireless transmission systems for synchronization, which is usually performed via cross-correlation, i.e. PN correlator, between the received signal and a locally generated PN sequence. However, the hardware implementation of such a correlator becomes the inhibiting bottleneck of integration due to the long tapped-delay line, particularly in the case of oversampling systems. Furthermore, few attempts have been made to improve the structure until now attributing to the random but simple coefficients of the PN correlator. This paper proposes a novel grouping and segmentation structure for filters with simple coefficients, such as a PN correlator. Remarkable hardware reduction has been achieved by multiplexing tapped-delay line and further operations skillfully. The arithmetic complexities of the conventional direct form structure and the proposed structure are compared based on a digital terrestrial multimedia broadcasting (DTMB) system. The advantages of the proposed structure are demonstrated by the FPGA implementation results.