A reduction method of tracking errors due to multipath waves in direct sequence spread spectrum systems
Satoshi Maruyamatoggle, Yasunori Iwanami, Tetsuo Ikedas · Electronics and Communications in Japan (Part I Communications) · 1987
Abstract The speed spectrum (SS) communication is a communication system which has excellent characteristics against noise and is suited to the code‐division multiplex. Numerous applications have recently been considered. The delayed lock loop (DLL) is employed frequently as the tracking circuit for SS communication, where, however, a phase tracking error is produced by multipath waves. This phase error degrades the large processing gain, which is one of the most remarkable features of SS communication. We have attempted to reduce the phase error. Here, it is assumed that the peak of the correlation function of the received wave is fixed as long as the object wave has an amplitude much larger than those of multipath waves. Under such an assumption, a circuit is proposed which aligns DLL to the peak of the correlation function. As a result of the operation experiment for the circuit, it is shown that the phase error due to the multipath wave can be reduced to approximately one‐fifth.