Multiuser generalized detector for uniformly quantized synchronous CDMA signals in wireless sensor networks with additive white Gaussian noise

We investigate the multiuser generalized detector, which is constructed based on the generalized approach to signal processing in noise [1]-[5], for uniformly quantized synchronous code division multiple access (CDMA) signals in additive white Gaussian noise channels of wireless sensor networks and compare with minimum mean-square error (MMSE) multiuser receiver discussed in [6]. The input/output relationship of the quantizer is represented by the gain plus the additive noise model. Based on this model, we derive the weight vector and the output signal-to-interference ratio (SIR) of the multiuser generalized detector. The effects of quantization and sampling of the multiuser generalized detector performance is characterized in a single parameter named ldquoequivalent noise variancerdquo which is a function of the sum of each active userpsilas signal-to-noise ratio (SNR), processing gain, and the number of quantization and sampling levels. The optimal quantizer step size, which maximizes the multiuser generalized detector output SNR, is also determined. Simulation results validate the accuracy of our theoretical analysis and confirms a superiority of employment of the multiuser generalized detector over minimum mean-square error multiuser receiver, which is analyzed in [6].