Real-Time Channel Sounding for Channel-Adaptive Data Links

The development of wideband mobile communications systems requires a good knowledge of the characteristics of the mobile channel as described by its impulse response. Such impulse response can be modeled as a tapped delay line with delays, amplitudes and phases associated with each tap. In order to obtain satisfactory estimates of these parameters and to determine delay spread, Doppler spread and the channel scattering function, a real-time channel sounder is required. This paper focuses on the hardware implementation of a real-time channel sounder, on an Innovative-DSP X6-400M Software-Defined-Radio platform based on a Xilinx Virtex-6 FPGA. The real-time channel sounder has been developed in VHDL and implemented with Xilinx ISE AND Xilinx System Generator design, simulation and analysis softwares. In order to visualize the measured channel scattering function, a graphical user interface has been created. Testing of the channel sounder using a channel emulator allowed to verify the proper operation of the project.