Study And Design Of Reconfigurable Demodulation Platform Based On FPGA

With the rapid development of mobile communication technology,the needs of users are becoming more and more diversified,and the modulation methods of communication are increasingly diverse and complex.In order to correctly demodulate the communication signals of different communication systems,it is necessary to recognize the modulation mode of the received signal and its signal parameter,the communication signal modulation recognition becomes more and more important.At the same time,in recent years,the size,power consumption,data processing performance of FPGA chip has made considerable progress,its cost is constantly reduced,compared to ASIC,its design cycle is shorter,and it has greater flexibility.Thus,automatic identification of communication signals on the FPGA is not only technically feasible but also becoming more and more important valuable.Wireless communication can be divided into two categories: single-user multi-standard and single-standard multi-user,single-user multi-standard include ASK(Amplitude shift keying),FSK(Frequency-shift keying)and so on;single standard multi-user include CDMA,TD-LTE and the like.In this paper,in the single-user multi-standard: 2ASK,4ASK,2PSK,4PSK,2FSK and 4FSK are chosen as the demodulation examples.In the single-standard multi-user,we chose CDMA.This paper designs a 5SGXEA7N2F45C3 chip based on Altera Stratix series chip as the hardware platform,and adopts chip GH8310 as the central controller to control the multi-mode demodulation of the wireless communication signal.The hardware platform includes FPGA module,MCU system,network port and serial port circuit for PC terminal controlling,power supply circuit and clock circuit.The two modulation modes of wireless communication signal can be configured based on FPGA,and single-user multi-standard demodulation mode can be automatically identified.In order to reduce the complexity of single-user multi-standard wireless communication demodulation automatic identification,the normalized instantaneous amplitude spectral density,the Kurtosis of normalized and further centered instantaneous amplitude and the net total of the frequency components of the modulated signal as theeigenvalue to recognize modulation method.The three eigenvalues are based on the normalized instantaneous amplitude eigenvalue,which greatly reduces the recognition complexity of the signal modulation method.In order to realize the wireless communication signal can be configured two types of modulation mode,using micro-controller MCU through the Localbus and RGMII to control communicate with FPGA,and PC-side through the network port and serial port control MCU,then indirectly control FPGA registers configuration,finally modulation mode can be configured.In this paper,two types of modulation modes can be configured through the controller to control the Localbus.The automatic recognition algorithm of single-user multi-standard wireless communication can be realized through FPGA,which reduces the complexity of operation and increases the recognition rate of modulation mode.Species.