Flexible Circuit Designs of M-ary Digital Modulations and Demodulations

Digital modulation techniques have become common in a variety of communication systems such as WiFi, Bluetooth, GSM, and others. Some applications may necessitate multiple modulations and demodulations. This paper describes the design and implementation of flexible circuit designs for M-ary digital modulations and demodulations in Cadence Virtuoso using CMOS 90nm technology. We have implemented the proposed flexible modulator and demodulator circuits to perform 4-ary Amplitude Shift Keying (ASK), 4-ary Frequency Shift Keying (FSK), 4-ary Phase Shift Keying (PSK), and 4-ary Quadrature Amplitude Modulation (QAM). Also, we have implemented a high throughput flexible 4-ary digital demodulator capable of performing multiple demodulations in parallel. By replacing individual circuits with a single enhanced circuit, the proposed designs can effectively reduce hardware costs.