Time integrating correlator (TIC) for real-time processing of spread-spectrum signals

Abstract

The TIC, an eight channel, 33 MHz digital time-integrating correlator chip, is described. As the component of a spread-spectrum receiver it calculates the correlation between an input signal (8 b) and a reference sequence (1 b) of length up to 2047. It consists of eight arithmetic units which are capable of handling eight different correlations in parallel. Each stage takes its reference signal from a 32 b delay line. The respective tap position for every correlator can be programmed individually through eight multiplexers. The correlation results are stored in registers and can be read during the following calculation period. The built-in interface logic and the programmable barrel shifter at the output allow for easy interfacing with different digital signal processors.<>