Performance modelling of open loop and closed loop multiuser multiple-input multiple-output-orthogonal frequency division multiplexing systems through channel analysis

Multiple-input multiple-output (MIMO) technology can be combined with orthogonal frequency division multiplexing to achieve diversity gain and improvement in system spectrum efficiency. The relative capacity of different system configurations are obtained using various channel characteristics. In this study, the probability density function (PDF) and the cumulative distribution function expressions of the condition number [i.e. the maximum to minimum singular value ratio (MMSVR)] of the channel state information matrix are derived. This ratio is directly related to noise enhancement in open loop (OL) multiuser MIMO systems. The probability density function (PDF) of MMSVR is directly used to compute the channel capacity if specific channels fail at high throughput. Capacity expressions in terms of MMSVR are derived for OL and closed loop (CL) multiuser MIMO systems. The capacity of both OL and CL systems are plotted for different system specifications, different fading channels and compared with each other under both semi and doubly correlated channels. A novel algorithm is developed to compute the channel capacity and PDF of MMSVR of a generic N_T × N_R MIMO system.