MIMO Multiple Input Multiple Output MIMO multiple input

MIMO (Multiple Input Multiple Output)

MIMO (multiple input, multiple output) Tx Rx Multiple antennas at both transmitters and receivers

SISO (single input single output) Wireless channel Tx Noise Rx True Symbol Noise corruption Goal of a communication system is to minimize noise corruption in estimated symbol

SIMO (Single Input Multiple Output)

SIMO – Selection Combining (SC)

SIMO – Selection Combining Selection combining picks the least attenuated antenna output

SIMO – Equal Gain Combining Effective Noise The effective noise is much lower than individual noises at antennas due to the smoothening effect of averaging

SIMO – Maximal Ratio Combining (MRC) Effective Noise MRC achieves the best combining with minimal effective noise

SIMO – Maximal Ratio Combining (MRC)

SIMO – Maximal Ratio Combining (MRC) Optimal noise smoothening matrix

MISO (Multi Input Single Output) Alamouti STBC (Space time block codes) Time slot 1 Antennas (Space) 1 2 slot 2

MISO – Alamouti STBC Optimal noise smoothening matrix

MIMO (Multiple Input Multiple Output) Tx Rx MIMO channel matrix

MIMO (Multiple Input Multiple Output) Tx Rx Rectangular MIMO channel matrix

Multi user MIMO (MU-MIMO) Rx

Multi user MIMO (MU-MIMO) Rx 1 Rx 2 Rx 3

Multi user MIMO (MU-MIMO) Pre multiply input vector x by matrix P, and transmit Px instead of x Choose P such that HP is a diagonal matrix = +