Weiguo Guan

A practical TDOA positioning method for CDMA2000 mobile network

The location technology based on time difference of arrival (TDOA) is one of the key technologies in The 3rd Generation Telecommunication. In this paper, TDOA positioning method based on modified Chan algorithm for CDMA2000 mobile network is proposed. Pilot delay measurement is adopted to realize TDOA positioning parameter detection. A mathematical model of TDOA positioning is established and the location solving method under ideal Gauss circumstance is put forward. In accordance with the trait of Non Light of Sight (NLOS) propagation delay obeying index distribution in the mobile communication environment, NLOS estimation covariance correction method is presented to decrease the NLOS influence upon positioning accuracy. Theoretical analysis and simulation results show that the positioning method in discussion is possessed with good qualities of positioning in actual channel environment. Meanwhile, with the low computational complexity, the proposed algorithm is well applied to mobile location of CDMA2000 telecommunication systems.

Optimization and implementation of digital matched filters based on FPGA

This paper introduces the principal of digital matched filters (DMFs), and based on Field Programmable Gate Array (FPGA), we make an analysis and optimization of DMFs which used in the quick acquisition of Pseudo-Noise (PN)-code for Global Position System (GPS). A structure as “Random Access Memory (RAM)-based shift register + folded” DMF is given in this paper. Compared with traditional folded DMF, this structure utilizes the rich resources of On-chip RAM in FPGA chip to decrease the consumption of Logic Elements (LEs) in FPGA chip. With this structure, the valuable resources of LEs in FPGA chip are saved. Throughout the compilation and the timing simulation by Quartus II, we prove that the structure we proposed can acquire PN-code effectively and be reasonable in saving LEs as the implementation of DMF based on FPGA. This design of DMF can be used in GPS receivers or other Code Division Multiple Access (CDMA) receivers.

Wavelet-Based Multi-Carrier Modulation on Power Line Communication

Multi-carrier modulation based on the wavelet is applied on power line communication to obtain high communication performance in this paper. The noise and attenuation model of power line channel for the data communication are established at first, on which the multi-carrier modulation method based on complex wavelet packet is adopted. Furthermore, the wavelet-based functions with various support lengths are selected in simulation to compare with the Fourier-based multi-carrier communication. Finally, the effects by selecting various wavelet-based functions are analyzed and compared. Compared through simulation results, the technique of wavelet-based multi-carrier modulation is more suitable than Fourier-based multi-carrier communication. Meanwhile, selecting the suitable wavelet-based functions with various support lengths can affect the performance of communication, especially the Bit Error Rate (BER).