Fractional interpolative timing advance and retard control in a transceiver

Abstract

Transmission of information between user equipment (UE) and base stations in a wireless network occurs using a stream of periodic data. A modem in the UE operates synchronized to a first clock source to produce the stream of periodic data at a chip rate. Transceiver circuitry is synchronized to a variable clock source to receive the stream of data from the first circuitry at a rate according to the variable clock source. A fixed phase relationship is maintained between the variable clock source and the first clock source while the data period is uniform by adjusting the variable clock in response to detected phase errors. Occasionally, one period of the periodic data is changed by a defined amount. The fixed phase relationship is restored over a number of periods in a gradual manner by changing the frequency of the variable clock by an amount. By restoring the phase relationship gradually, quality degradation of the transmitted signal is reduced.