High frequency radio including an adjustable-bandwidth tunable bandpass filter for improved detection of incoming calls and methods for processing incoming calls

A method for a high frequency (HF) radio to process an incoming call from another HF radio, the method comprising:

• selecting a staring frequency band and a plurality of assigned Automatic Link Establishment (ALE) channels within the staring frequency band, based on values of parameters that are indicative of ionospheric propagation conditions at a given time;
• obtaining, at an adjustable-bandwidth tunable bandpass filter, from at least one antenna, first HF signals within a HF band;
• providing, by the adjustable-bandwidth tunable bandpass filter, only second HF signals within the staring frequency band, the second HF signals including one or more analog calling signals that are indicative of incoming calls, wherein the staring frequency band is a subset of the HF band, and wherein a bandwidth of the staring frequency band is adjustable;
• converting the analog calling signals to one or more digital calling signals that are indicative of the incoming calls, by a first receive path connected to an output of the adjustable-bandwidth tunable bandpass filter;
• monitoring, by a plurality of receivers, the ALE channels, each receiver of the receivers being configured to monitor a different assigned ALE channel of the assigned ALE channels for the digital calling signals;
• and
• establishing a communication link between the HF radio and the another HF radio, in response to a given receiver of the receivers decoding a given digital calling signal of the digital calling signals that is indicative of the incoming call from the another HF radio, the given digital calling signal being communicated from the another HF radio over a given assigned ALE channel of the assigned ALE channels.

A non-transitory computer readable storage medium having computer readable program code embodied therewith, the computer readable program code, executable by at least one processor of a computer to perform a method for a high frequency (HF) radio to process an incoming call from another HF radio, the method comprising:

• selecting a staring frequency band and a plurality of assigned Automatic Link Establishment (ALE) channels within the staring frequency band, based on values of parameters that are indicative of ionospheric propagation conditions at a given time;
• obtaining, at an adjustable-bandwidth tunable bandpass filter, from at least one antenna, first HF signals within a HF band;
• providing, by the adjustable-bandwidth tunable bandpass filter, only second HF signals within the staring frequency band, the second HF signals including one or more analog calling signals that are indicative of incoming calls, wherein the staring frequency band is a subset of the HF band, and wherein a bandwidth of the staring frequency band is adjustable;
• converting the analog calling signals to one or more digital calling signals that are indicative of the incoming calls, by a first receive path connected to an output of the adjustable-bandwidth tunable bandpass filter;
• monitoring, by a plurality of receivers, the ALE channels, each receiver of the receivers being configured to monitor a different assigned ALE channel of the assigned ALE channels for the digital calling signals;
• and
• establishing a communication link between the HF radio and the another HF radio, in response to a given receiver of the receivers decoding a given digital calling signal of the digital calling signals that is indicative of the incoming call from the another HF radio, the given digital calling signal being communicated from the another HF radio over a given assigned ALE channel of the assigned ALE channels.