Time-Domain MIMO Channel Sounder Based on Code-Division Multiplexing

In this paper, a multiple-input multiple-output (MIMO) time-domain channel sounder based on code-division multiplexed signals is presented. This measurement system is formed by commercial and multipurpose equipment such as a base-band pulse generator, a wideband I/Q modulator, and a digital store oscilloscope. Apart from its measurement speed, the main advantages of this proposal are its low cost and the re-utilizable capability of the equipment. The implementation of the channel sounder is described and the MIMO transfer matrix, H(τ), is computed in an indoor environment.