Patent ID: 8675744
Filing Date: 2014-03-18
Classification: H04K,H04L

Abstract:
1. In a communications system wherein a receiver receives signals comprising a plurality of symbols, wherein each symbol is represented over a plurality of subcarriers each having distinct frequency extent and wherein an amplitude and relative phase of the subcarriers are selected by a transmitter from a predetermined set of N discrete values, where N is an integer greater than 1, and wherein reception of a signal by the receiver is subject to at least phase or timing noise and uncertainty as to one or more of phase of the signal and the timing of the symbols, a method for determining at least approximations of the phase or timing, comprising: receiving a symbol of the plurality of symbols, wherein the symbol comprises a plurality of components, wherein each component is represented as the signal over a distinct one of a plurality of subcarriers with each subcarrier having a distinct frequency extent, the symbol having thereon an imposed uncertainty as to one or more of phase and frequency; transforming the plurality of components, which have data signals carried thereon are from the transmitter and not known to the receiver in advance of receiving the components, into transformed component signals that are independent of the data signals carried on each of the components of the plurality of components, thus forming a plurality of transformed component signals each corresponding to a component of the plurality of components; using the plurality of transformed component signals in an estimation of the imposed uncertainty; transforming a given untransformed component into its corresponding transformed component by generating a signal whose phase is N times that of the phase of the given untransformed component; and adjusting for a known phase offset as needed, thereby converting the given untransformed component representing an unknown one of the set of N discrete values plus an unknown phase or timing offset into the corresponding transformed component whose phase is independent of the unknown value with which the given untransformed component was originally encoded but the corresponding transformed component remains dependent on the unknown phase offset or timing, where the method is performed by one or more hardware processors.