Narrowband jammer resistance for MIMO OFDM

Multi-input multi-output (MIMO) antenna systems provide the user with additional degrees of freedom over traditional single antenna (SISO) system to enable optimum transmission. This paper focuses on the use of multi-antenna techniques to compensate for in-band interference in scatter rich environments.We consider the effects of narrowband interference in a collection of typical channels with delay spreads and losses representative of both indoor and outdoor environments. We show the performance of a multi antenna technique that can be used to combat these types of interference. We present an analysis of the performance of this technique in channels with varying amounts of dispersion. Both simulation and experimental results will be discussed and presented. The experimental results are collected from testing performed on a highly versatile MIMO OFDM testbed developed at Silvus Technologies. The testbed uses a waveform similar to 802.11 n. The chosen method will show up to 30 dB rejection of the interfering signal, thereby allowing us to achieve roughly 50% of the unjammed throughput in the presence of strong jammer. We also show that this method is proven on real-time hardware, where we successfully received a 23 Mbps stream of data with a signal to interference ratio of -20 dB.