Interference-robustness improvement in BPSK receivers for the enhanced WWVB broadcast

Abstract

Radio controlled clocks (RCCs) based on the WWVB broadcast, commonly referred to as “atomic clocks”, might experience relatively high levels of on-frequency interference from the equivalent MSF time-code broadcast from the UK, particularly on the East Coast. The problem may be further exacerbated by a random orientation of the RCC device, which might favor the reception of the interfering signal. While the legacy receivers for WWVB, based on envelope detection, are particularly vulnerable to such interference, a basic coherent BPSK receiver for the enhanced broadcast demonstrates a 25 dB performance advantage in interference immunity. An interference cancellation technique is proposed, to further enhance the performance of the coherent BPSK receiver, achieving an additional 14 dB improvement in interference rejection.