3GPP ACLR and EVM measurements for millimeter-wave wireless backhaul applications at 60GHz

This paper analyzes the achievable signal quality of a novel system architecture for small cell remote units with integrated millimeter-wave wireless backhaul. In contrast to existing systems, the data signal on the backhaul link uses the same 3GPP compliant signal as with the access link serving the users. The small cell remote unit only consists of a simple frequency conversion from backhaul to access frequencies. We simplified the measurements by using wave guide based variable attenuators to emulate the wireless link in our test setup. Its sufficient linearity and phase noise performance at 60GHz was proven with measurements of a single-carrier WCDMA signal easily meeting the 3GPP ACLR and EVM requirements, even with 10dB dynamic on the backhaul link. Moreover, the required broadband capability is demonstrated using an LTE signal with 20MHz bandwidth.