An SMSE Implementation of CDMA with Partial Band Interference Suppression

A spectrally modulated, spectrally encoded (SMSE) framework is adopted for implementing code division multiple access (CDMA) with partial band interference suppression. SMSE signals are constructed within an architecture governed by cognitive radio (CR) principles and supported by software defined radio (SDR) implementation, a union referred to as CR- based SDR. Orthogonal frequency division multiplexing (OFDM) signals, a foundational part of future 4G systems, are collectively classified as SMSE because data modulation and encoding are applied in the spectral domain. Framework applicability was demonstrated for realistic 4G signals by illustrating consistency between resultant analytic SMSE expressions and published results. Framework implementability and flexibility is further demonstrated herein using more complex CDMA signal structures. Modeling and simulation results are presented for a form of multi-carrier CDMA using polyphase codes with adaptive spectral notching (interference avoidance). Collectively, the SMSE implementation of this system correlates very well with theoretical predictions for multiple access scenarios.