A Compact Test System for Simulating Multipath Interference

Abstract

Fading and inter-symbol interference (ISI) arising from multipath effects are a common source of both latency and packet errors in wireless communications. Test methods often require large environments to produce long delays that are enough to affect the communications between a transmitter and receiver. This paper presents a simple, compact test method to produce and isolate effects from multipath interference simulating these effects produced by discrete distances. Signals with controlled delays can be created and combined using multiple antennas in two isolated small (2 foot/60 cm) cubes constructed with microwave absorber. We demonstrated this with a pulsed RF signal and a signal from an 802.11 n access point with an internal antenna. This method can be further extended to provide a compact test-bed for almost any wireless interference or coexistence test.