ASSESSING ANTENNA SUITABILITY FOR DEPENDABLE MIMO-OFDM INTERFERENCE ALIGNMENT THROUGH MEASUREMENTBASED ANALYSIS

Interference alignment (IA), a possible transmission method, permits practically all degrees of freedom (DoF) in K-user multiple-input multiple-output (MIMO) interference channels. Independent MIMO channels, which are not frequently used in practise, especially indoors, were used to get the optimal DoF of IA systems. In realworld settings, the data sum-rate & symbol error-rate of IA are significantly worsened due to correlation across MIMO channels lowers the signal-to-noise ratio (SNR) of signal that is received after alignment. This has led to evidence in literature that altering the distance among network nodes and the spacing among the antennas inside each node can be utilized to decrease spatial correlation while achieving an appropriate sum-rate of IA in real MIMO orthogonal frequency-division-multiplexing (MIMOOFDM) interference channels. With the aim of improving sum-rate and/or error-rate performance in practical channel conditions while preserving the bare minimum spatial antenna separation of 0.5 wavelengths inside each node, we propose employing bulk or per-subcarrier transmit antenna selection for MIMO-OFDM IA systems in this work. Maximum sum-rate and minimal error-rate are 2 selection criteria that are taken into account. A limited per-subcarrier antenna selection is used to prevent subcarrier imbalance across each user's antennas, which is brought on by per-subcarrier selection. To make the ideal procedure less computationally difficult, a sub-optimal antenna selection approach is also suggested