Efficient hardware implementation for detecting CSS-based Loosely Synchronous codes in a Local Positioning System

Loosely Synchronous (LS) codes improves the performance of Local Positioning Systems (LPS) in terms of noise immunity, capability of simultaneous measurements and precision in the location, provided that the multipath spread and the relative time offset between the codes are within the zero correlation zone (ZCZ) that they achieve in their correlation functions. Furthermore, these codes can be very efficiently generated and correlated if compared to a straightforward implementation. This work presents the hardware implementation of the correlation tasks associated to an ultrasonic LPS based on LS sequences generated from Complementary Sets of Sequences (CSS). This implementation is able to carry out all the correlation processing tasks in a time shorter than the sampling period.