Patent ID: 6804310
Filing Date: 2004-10-12
Classification: H04B,H04L

Abstract:
A decision feedback loop apparatus for a receiver for channel estimation and de-rotation of complex input symbols derived from a sampled information signal received via a channel, which information signal contains data organized into successive time slots, each slot containing a predetermined series of pilot bits during a first portion of the slot and a series of data bits during a second portion of the slot, said apparatus comprising:a first multiplier for multiplying the complex input symbols with estimated conjugate channel coefficients, which are derived from a feedback signal, to form complex soft symbols to be used for channel decoding; a hard decision device for forming complex hard symbols from the complex soft symbols; a pilot generator for generating a series of complex pilot symbols corresponding to the predetermined series of pilot bits in the information signal; and a second multiplier for multiplying a first signal at a first input, which is derived from the complex input signal, with a second signal at a second input to form the feedback signal at an output, wherein the second signal is derived from the complex pilot symbols during the first portion of the slot and from the complex hard symbols during the second portion of the slot.