A Digitally Controlled Multichannel Spectrally Efficient Low-Power Transceiver for Ultra-Wideband Cognitive Radio Applications

A multichannel transceiver design with low hardware complexity, flexibility and efficient spectrum use intended for Impulse Radio (IR) Ultra-Wideband (UWB) apertures, is proposed in this paper. The transceiver supports 14 channels and is implemented in TSMC CMOS process. The transmitter adopts a symmetrical triangular narrow pulse generator, a multiband LC-VCO, a mixer and a Variable-Gain Amplifier. A digital control of transmitter output power and carrier frequency is achieved by a current-steering Digital-to-Analog Converter (CS-DAC). The receiver follows the noncoherent Energy Detection (ED) scheme including Low-Noise Amplifier (LNA) which takes the benefits of the body biasing technique to further reduce power consumption, squarer and comparator. The LNA achieves high gain of up to 30dB allowing to enhance the receiver sensitivity which is -83.7dBm at 25Mbps. The transmitter provides output pulses with a width of 3ns, a pulse repetition rate of 20ns and a maximum Power Spectral Density (PSD) of -42dBm/MHz. The power consumptions of transmitter and receiver are 35.6pJ/bit and 0.207nJ/bit at 25Mbps, respectively. Maximizing utilization of the scarce wireless spectrum, enhancing spectral flexibility and efficiency and reducing power consumption are the main contributions brought by this work, enabling this transceiver to be able to deal with the current debate on producing single multifunctional Cognitive Radio (CR) UWB systems.