Signal-to-interference ratio estimation based on decision feedback

Signal-to-interference ratio (SIR) is an important metric of communication link quality. For wireless data systems SIR estimates are used in several control actions and for optimal allocation of radio resources. This paper first develops a new SIR estimator based on data symbols and then derives an approximate analytic expression for its mean squared error (MSE) function, the accuracy of which is validated using simulations. Results show that the MSE of the new SIR estimator is significantly smaller than the MSE of other widely used SIR estimators.