Modulator/Demodulator Approach for a Software Radio

Software radio basically refers to an ensemble of techniques that permit the reconfiguration of a communication system without the need to change any hardware system element. That goal is to produce communication devices capable of supporting several different services, applications, and standards. In particular one can imagine a given devices that should support several digital mobile telephony standards, service and function by just changing its software. Current devices can provide only one type of standards due to limitations mainly imposed by their analogue technology parts. The software radio as a promising solution for the future of 4G wireless communications, because of its ability to provide flexible architecture, was enabling multi-mode, multi-band, multi-services, and multi-standards devices. This paper presents a multi-modes modulator/demodulator conception for a software radio. For it the modulator design is based to the multi-modes mapper and DDS bloc. The multi-mode mapper generate symbol mapping using a constellation diagram to implement a variety of mapping schemes for multi-mode modulator design. This bloc is used by many modulation schemes.  Example includes quadrature amplitude modulation (QAM), phase shift keying (PSK), and orthogonal frequency division multiplexing (OFDM). The demodulator is based to algorithm for automatic modulation recognition that exploits the flexibility of a software radio. Our algorithm is based to calculate several parameters and used a threshold metric. A purposed approach can be exploited a flexibility for software radio.