High-performance Multi-resolution Spectrum Sensing Circuit

With the development of the society, the spectrum resource becomes more and more scarce. However the practical spectrum is not adequately utilized. Cognitive radio, which can take advantage of unused spectrum to transmit data, is an important technology to settle the problem of frequency resource shortage, and enhance the spectrum using rate. Spectrum sensing technology is required by cognitive radio to process quick and reliable detection on frequency spectrumIn this thesis, we summarize various facets of spectrum sensing include spectrum opportunity, problems and challenges, various spectrum sensing technology and systematic solution with multiple technology and cross-layer corporation. We put emphasis on the multi-resolution spectrum design application in cognitive radio fast sensing function. We discuss the basic theory and implementation of the multi-resolution spectrum sensing and also the key issues on circuit realization. A novel multi-resolution spectrum sensing circuit, to realize the spectrum sensing function in cognitive radio, with improved sensing time is proposed. Putting reconfigurable filter before the multiplier, this design breaks the tradeoff between sensing time and frequency resolution. In addition, the frequency resolution could be adjust freely by the reconfigurable filter.Implemented in 0.13μm CMOS process, the circuit operation at 1.2 V supply voltage dissipates 30mW of power with effective area 0.96mm2. Test results shows the spectrum resolution covers 1 MHz to 20 MHz; the sensing sensitivity achieve-65 dBm with 31 dB dynamic range; with only 1μs sensing time per frequency point. This design realize the function of fast spectrum sensing.