Abstract: A SINR estimator receiving a symbol stream has a delay element coupled to the symbol stream to produce a delayed symbol stream, which is also coupled to a conjugator. A first multiplier forms a product from the symbol stream and the output of the conjugator, thereafter summing these values over an interval L and scaling by L to form a correlated power estimate Cn. A second multiplier forms a product from the symbol stream which is multiplied by the conjugate of the input, thereafter summing these values over the preamble interval 2L and scaling by 2L to form a non-correlated power estimate Pn. Cn and Pn are compared to generate an SINR estimate.

Abstract: A quantizer has a plurality of decision blocks, each coupled from input to output, where each decision blocks output generates a binary value that is an unchanged decision block input if the decision block input is below the threshold input level divided by a power of 2, or the decision block subtracts a threshold divided by the power of 2 and passes this result as the decision block output. The quantizer output is formed from the bits of each comparison from each decision block. The threshold is developed from a channel noise variance which may be multiplied by a scale factor related to coding type and rate. In this manner, a large number of input bits to be quantized may be converted to a smaller number of quantizer output bits, while preserving the dynamic range information required to correctly decode signals passed through a communications channel having multi-path frequency selective fading.