A new design technique of OTA based M-ary modulator and demodulator

A new OTA based structure of M-ary modulator & demodulator have been proposed in this paper. Unlike conventional system, A/D D/A converters are not used in the proposed circuit. M-ary ASK modulator and demodulator are synthesized in a systematic and hierarchical manner. As a result, modulation and demodulation with different symbol size, M=2n where n=1 2, 3, 4 can be performed in this proposed methodology. Theoretical analysis of bit error rate for the QASK and M-ary ASK has been done. The M-ary ASK modulator has been simulated using SPICE. The simulation results confirm the reliability and accuracy of the design.

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