Single Radio-Over-Fiber Link and RF Chain-Based 60 GHz Multi-Beam Transmission

Abstract

An efficient multi-user transmission scheme at 60 GHz using a single-feed leaky wave antenna (LWA) and hence requiring only a single radio-over-fiber link and single RF chain is presented. A subcarrier multiplexed signal carrying different users' data is transported over 2.2 km of optical fiber and then upconverted to the 60 GHz band for transmission to multiple spatially separated users through the beam steering characteristics of the LWA. An overall sum data rate, the combined rate from all users, of 10.6 Gb/s using 16-QAM modulation serving ten users over a transmission bandwidth of 3.05 GHz or 20 users with QPSK over 6.1 GHz span, is achieved experimentally. The theoretical sum data rates for 6.1 GHz bandwidth for different numbers of users are calculated, considering the SNR degradation due to the angularly dispersed LWA beam, showing that data rates over 30 Gb/s can be obtained. Finally, a system design that improves coverage and spectrum efficiency through operating multiple LWAs with a single RF chain is demonstrated.