Implementing of Forward Link Channel CDMA2000-1x System by Using Simulink HDL Coder

Abstract

This work is a proposed simulation for forward link channel of CDMA2000 -1x system by using QPSK, 8QAM and 16QAM, and converting the proposed system to VHDL language by using Simulink HDL Coder for implementing in FPGA board. The results of simulation for forward link channel of CDMA2000 system shows improvement when using three levels of codes (LPNC, Walsh code and complex coding) in the present of AWGN for QPSK modulation the system performance is improved from (1.8 to 1.9) in dB for BER (Bit Error Rate) 10 to 10 and for 8QAM the system performance is improved at (2.9) in dB for BER 10 to 10 and for 16QAM the system performance is improved from (1 to 1.2) in dB for BER 10 to 10 . The results of simulation in the present of AWGN and Rayleigh fading channel are improvement within (0.5) in dB for the different Doppler Frequencies (5 - 230Hz). The Simulink HDL Coder has been used for converting the MATLABSimulink models to VHDL language. The verification of the generated VHDL code has been done using Altera-ModelSim program, while the synthesis reports and board programming files have been obtained using the Quartus II program. System implementation has been done using FPGA technology with Altera Cyclone II boards. The implementation of the forward link channel by using Simulink HDL coder shows feasibility and flexibility in solving the problem of complex multiplication of complex spreading code also the practical results were closed to that obtained from ModelSim program.

Keywords

• cdma
• fpga
• lpnc
• vhdl