Pre-equalized MIMO transmission over analog RoF downlink in the presence of gain imbalance

In this article, we propose a pre-equalization method in a wired-wireless multiple-input and multiple-output (MIMO) transmission over an analog radio-on-fiber (A-RoF) network. The MIMO transmission based on A-RoF suffers from un-flat and unbalanced response in the wired part, resulting in decreased channel capacity. A partial pre-equalization technique for wired part is compared to the one for the joint channels of wired-and-wireless by using 2 × 2 transmission of orthogonal frequency division multiplexing (OFDM) in a 5-GHz band testbed.