The effect of frequency offsets on the performance of FLEX(R) simulcast systems

Zero-beating is a phase cancellation u` condition that occurs when two or more transmitters send the same data at slightly offset frequency. It results in periodic signal cancellations which degrade the coverage performance of simulcast systems. This paper presents a comprehensive study of the zero-beating effect that occurs in simulcast environments. Zero-beating is characterized in the time, frequency, and spatial domains. The simulcast performance of FLEX(R) simulcast systems is evaluated through computer simulations, laboratory tests and field measurements. Based on the obtained results, a frequency offset plan that enhances FLEX(R) simulcast performance is recommended