A Novel E-band Testbed for Polarization MIMO -OFDM Systems with Wideband IQ Imbalance Compensation

Considerable research efforts have been made into 5G systems, in which wireless backhaul plays a key part. This paper presents a novel E-band testbed for 5G backhaul applications with wideband IQ imbalance compensation. It is based on OFDM to compensate the effect of wideband channel distortions as well as RF impairments. Moreover, line-of-sight polarization MIMO with two orthogonal polarizations is applied to enhance the data rate, which in combination with OFDM results in a simple equalization approach. In this testbed, carrier frequency offset and Tx/Rx IQ imbalance are jointly estimated and compensated. We describe how the testbed was designed. Then, we apply the IQ imbalance compensation and demonstrate that a data rate of 20 Gbps can be achieved in an actual outdoor environment distances of 900 m.