Biased SNR estimation using pilot and data symbols in BPSK and QPSK systems

摘要: In wireless communications, knowledge of the signal-to-noise ratio is required in diverse communication applications. this paper, we derive variance maximum likelihood estimator data-aided and non-data-aided schemes for determining optimal shrinkage factor. The factor usually constant that multiplied by unbiased estimate it increases bias slightly while considerably decreasing so overall mean squared error decreases. closed-form biased estimators binary-phase-shift-keying quadrature-phase-shift-keying systems are then obtained. Simulation results show proposed method lower than low moderate conditions.