SSB/FDM Utilizing TDM Digital Filters

Theoretical and practical results in the field of digital filtering encourage the examination of digital filters for use in multiplex communication systems [1]-[3]. Although their economic breaking in will only come in combination with large-scale integration of digital circuits, it appears worthwhile to study their feasibility for various applications [4]-[7], [9]. One application of particular interest is the digital realization of single-sideband frequency-division multiplexing (SSB/FDM), which leads to the study of the digital realization of the SSB-channel bank which is internationally known as the first multiplexed group in the frequency range of 60-108 kHz. This paper describes the conversion of voice-frequency channels into SSB/FDM signals using digital filters. A brief analysis explains the implications of the various steps of signal processing in the time and frequency domains. The digital realization of a channel bank is explained in block diagrams. It is shown that the SSB/FDM signal appears simultaneously as a TDM/SSB signal (TDM/FDM/SSB).