Design Of Programmable Modulation And Demodulation Baseband Transceiver For Short Distance Wireless Communication

The rapid development of wireless communication put forward a higher standard to integrated circuit design and manufacturing technology. Especially, the short-range wireless communications system is close to our lives, to design a flexible short-range wireless communication baseband circuits has important practical significance.A programmable digital baseband system is designed for short-range wireless communication applications. Through the analysis about the application background and research status of short-range wireless communication technology, a digital baseband system with programmable modem modes including (Gaussian) Frequency Shift Keying (FSK/GFSK), Minimum Shift Keying (MSK), Binary Difference Frequency Shift Keying(2DPSK) and Orthogonal Differential Phase Shift Keying(QDPSK) is determined based on the idea of software radio. And the rate of the design can change from 1.2kbps to 307.2kbps. The specific architecture compatible with those modem modes is given out on this basis. Design optimizations and algorithm simulations are completed for the key circuit modules of the programmable baseband system including data processing circuit, direct digital frequency synthesis circuit, digital down conversion circuits, differential demodulation circuit and synchronous circuit. It turns out that the modified synchronous circuit can reduce the desired signal-to-noise ratio by 0.4dB when achieving a bit error rate of 10-3. Considering the implementation complexity of the circuit and system performance, the RTL design and simulations of the programmable baseband system are completed. The results of compile turn out that the design can achieve a modem mode compatible system without significantly increasing the consumption.FPGA verification platform is built to complete the functional and timing verification process and the testing about the programmable baseband system is also carried out based on FPGA implementation. Verification results show that the data can be transmitted and received well in all cases that have been tested. Testing results show that the root mean square error is less than 2% and the baseband receiver can achieve bit error rate of 0.1% at the signal-to-noise ratio of 12dB in the worst cases, which meet the design requirements.