Why are all MIMO techniques always in a multiple of 2 (i.e. 2x2, 4x2, 4x4, 8x8)? Why aren't there MIMO schemes such as 3x3, 5x5, etc.?
For Downlink - 2*2 and 4*2 MIMO configurations, Which one gives better throughput and why ?. Both have 2 receiving antennas.
