.gsm / Td-scdma Dual-mode Communication System Channel Estimation Realization

In the mobile communication system, the signal amplitude fading and phase distortion will occur when the actual signal transmitted by the radio channel. And it is very important to provide the accurate channel estimation for the interference elimination of non-ideal factor. At present, China's mobile communications system is in the process of the transition from the 2G to 3G.And these two communication system will coexist for a long period of time. Global System for Mobile Communications (GSM) is the world's most widely used 2G digital mobile communication system. Time Division Synchronous Code Division Multiple Access (TD-SCDMA) is the 3G standard protocol which is based on GSM system and is supported by China.This paper designed a new structure of the channel estimation module, which integrates the channel estimation module of GSM and TD-SCDMA dual-mode system, instead of hardware simple overlay method, to achieve channel estimation for dual-mode protocol.Firstly, this paper introduces the basic concepts of GSM/TD-SCDMA dual-mode communication system protocol, as well as the basic achievement method of dual-mode communication system on the today's market and indicate that the importance of the channel estimation module in dual-mode communication systems.Secondly, this paper presented the channel estimation of dual-mode system and its core modules FFT processor from the algorithm analysis to the hardware implementation.Thirdly, this paper introduce how to build a GSM/TD-SCDMA dual-mode downlink system, and make it to co-simulation with channel estimation module in order to validate the s correct of t the channel estimation module design.Finally, the paper analyze and compare the simulation results of dual-mode communication system and the hardware implementation result of FFT, which is the core module of the channel estimation.The results shows that channel estimation module which is applied in the dual-mode system has high performance. The simulation result indicates that the calculated quantity is reduced 43% than traditional method. And GSM and TD-SCDMA BER are both improved. The design has been verified by the Altera platform and synthesized in the 0.18μm 1P6M technology. The power consumption is about 46.8 mW. And the data throughput rate can have a 4-fold increase by less hardware consumption.