Interleaved Training for Massive MIMO Downlink via Exploring Channel Temporal Correlation

In this letter, we propose a channel temporal correlation-aware interleaved training (IT) scheme (CTC-IT) to further reduce the training overhead of basic IT for massive multiple-input-multiple-output downlink, particularly in frequency division duplexing mode. First, we derive the current channel conditional distribution given historical training information. Then, analytical and closed-form expressions are derived for the probability that obtaining the additional information of each untrained antenna meets the signal-to-interference-plus-noise-ratio (SINR) requirement for the general case and the case of a large number of users. And a max-min design is proposed to select the antenna that maximizes the minimum probability of each user’s SINR satisfaction. Simulations show the performance advantage of CTC-IT over basic IT in temporally correlated channels.