A general analytic framework for spectrally modulated, spectrally encoded signals

Abstract

This paper presents a general analytic framework which mathematically incorporates the waveform adaptivity and diversity found in spectrally modulated, spectrally encoded (SMSE) signals. It is envisioned that waveforms of future fourth generation (4G) radios will cognitively adapt to changing channel conditions, traffic loads, interfering signals, and spectrum availability. Some proposed 4G architectures are considering SMSE techniques as the key enabler for cognitive communication. Hence, it is instructive to develop a framework from which SMSE signals can be derived, analyzed, and implemented for both single-channel and multi-channel systems. This paper presents a concise mathematical model which generally, accurately, and completely describes the characteristics of SMSE signals. As developed, the model is easily implementable using software defined radio (SDR) techniques. To demonstrate the model's utility, examples are provided for three current SMSE techniques, including OFDM, MC-CDMA, and the TDCS.