Emulation techniques for small scale fading aspects by using reverberation chamber

Reverberation chambers (RVCs) are used to provide an efficient and reliable testbed for emulating the wireless channel effects in the laboratory environment. In the literature, various techniques have been studied to enrich the channel emulation capabilities of RVCs. However, insufficient control of some of the emulated channel characteristics (such as time and frequency dispersions) still leaves an open problem for RVC-based channel emulators. In this paper, novel channel emulation techniques by using RVC are introduced to enhance the flexibility in controlling the emulated time and frequency dispersions of the channels. Surface acoustic wave delay lines and power controllers (i.e., amplifiers and attenuators) are used to add degrees of freedom for manipulating the power delay profile during delay spread emulation. This technique also overcomes the challenge of achieving higher delay spread values with benchtop-sized RVC. The second technique is aimed to control the Doppler spectrum shape emulated in the chamber by judiciously placing radio frequency absorbers around the mechanical stirrer. Experimental and mathematical analyses are conducted to evaluate the proposed techniques, and the results show that the proposed methods can improve the channel emulation in the RVCs.