HIGH FREQUENCY RADIO INCLUDING AN ADJUSTABLE-BANDWIDTH TUNABLE BANDPASS FILTER FOR IMPROVED DETECTION OF INCOMING CALLS AND METHODS FOR PROCESSING INCOMING CALLS

摘要

A high frequency (HF) radio configured to process an incoming call from another HF radio, the HF radio comprising: an adjustable-bandwidth tunable bandpass filter configured to provide HF signals that are within an adjustable-bandwidth Staring Frequency Band (SFB), being a subset of a HF band, the HF signals including analog calling signals that are indicative of incoming calls; a receive path configured to convert the analog calling signals to digital calling signals; a plurality of receivers configured to monitor assigned Automatic Link Establishment (ALE) channels within the SFB for the digital calling signals; and a controller configured to: establish a communication link between the HF radio and the another HF radio, in response to a given receiver of the receivers decoding a digital calling signal that is indicative of the incoming call; and select the SFB and the assigned ALE channels, based on an indication of ionospheric propagation conditions.