Nordic Semiconductor ASA
RADIO COMMUNICATIONS

Abstract:

A radio receiver device, arranged to receive a radio signal modulated with a plurality of data symbols, comprises an analogue-to-digital converter that is clocked by a first clock signal and is arranged to receive the radio signal and produce a digital signal. A digital circuit portion, arranged to receive the digital signal produced by the analogue-to-digital converter, comprises digital processing units that are clocked by a second clock derived from the first clock and arranged to process the digital signal and produce an output signal at an output sample rate. A counter, clocked by the second clock, counts a number of samples at the output sample rate. A network timer clocked by a reference of a network clock produces a receiver enable flag which is synchronised to the first clock. The counter is enabled only when the synchronised flag is set. The counter is arranged to set a trigger flag when the number of samples exceeds a predetermined threshold. A buffer is arranged to receive the output signal and is enabled only when the trigger flag is set.