Exponential Effective SINR Computation for LTE Networks

The exponential effective SINR is a fundamental tool for evaluating and studying next generation orthogonal frequency division multiplexing (OFDM) based wireless systems such as LTE. It converts the different gains of multiple subchannels, over which a codeword is transmitted, into a single effective flat-fading gain with the same codeword error rate. It enables fast link adaptation by allowing each user to compute a precise channel quality indicator (CQI), which is fed back to the eNodeB for downlink rate adaptation and scheduling. For a given practical case, exponential effective SINR prediction relies on the approximation of the sum distribution of correlated lognormal random variables. The present work focuses on two major issues. First, the establishment of a simple and effective approximation method for the sum of dependent lognormal random variables based on log skew normal distribution. Second, the study and the investigation of closed-form expression for the exponential effective SINR spatial distribution in LTE downlink and uplink.