Design and Implementation of Channel Estimation and Equalization of Indoor Positioning System Based on UWB

Precise indoor positioning is becoming increasingly important in commercial, military and public service applications for tracking people and asset. Ultra wide band (UWB) can provide high accuracy position with strong anti-jamming and low power consumption. It is very suitable for indoor positioning application. This paper will put emphasis on indoor positioning system based on UWB. Analysis and implementation of indoor positioning systems based on UWB require an accurate channel model to determine that can be achieved, to design efficient modulation and coding schemes, and to develop associated signal-processing algorithms and effective method of hardware implementation. The structure of indoor positioning system based on UWB is introduced and some system parameters and modulation are determined in this paper. After description the structure of receiver and transmitter of system, a detailed analysis of UWB indoor channel characteristics is given and some algorithms of channel estimation and equalization are discussed in this paper. Some channel estimation techniques based on preamble training sequences and pilot sub-carriers are researched in depth. Further more, the linear estimations of least square (LS) and minimum mean square error (MMSE) are analyzed and compared under different UWB channel conditions and then suitable algorithm for this system is selected. Based on this selection, a scheme for FPGA implementation is proposed, and then some most significant modules for channel estimation and equalization has validated with Xilinx Virtex IV FPGA. It has been shown by some modelsim simulations that this channel estimation and equalization approach has some merits, such as simple implementation and less consumption of resource. It can meet the requirement of system design and some good performances can be achieved.