Theory and practice for modelling the broadband acquisition in HF transmissions

Abstract

Traditional use of the HF band is limited mostly to 3 KHz for both voice and data transmission, and therefore, most of the transceivers bandwidths are also adapted to this profile. However, there are some initiatives that clearly state that much broader bandwidths may be use with the corresponding data rate increase and performance improvement in the HF band [1,5]. Due to the increased bandwidth, a broadband transceiver receiver has to cope with a broader acquisition bandwidth with strong signals that degrade the Analog to Digital Converter (ADC) performance while receiving our (often) much weaker desired signals. This current paper has three main steps in order to evaluate under which circumstances the degradation is noticeable regarding the interchannel separation and the powers ratio. Indeed, our objective is to determine how much the interference has to be mitigated in the analog domain in order to split its cancellation partly before the ADC, and partly after it in the digital domain where much powerful techniques are available.