US 2010/0135447 A1 · METHOD AND AN APPARATUS FOR SYNCHRONISING A RECEIVER TIMING TO TRANSMITTER TIMING

Abstract

The present application relates to a method and an apparatus for synchronising a receiver timing to a transmitter timing using a known preamble of a signal. In at least one embodiment of the method and/or the apparatus of the present application, a power normalised cross-correlation metric (PNCC metric) is estimated based on a signal power and a noise floor power. According to a first embodiment, two cross-correlation functions, one based on the PNCC metric and the other based on a cross-correlation metric, are used to decide if synchronisation events occur and based on the analysis of time indexes and PNCC magnitude values, a timing synchronisation index used to synchronise receiver timing to transmitter timing is determined. According to a second embodiment, the cross-correlation function based on the PNCC metric is used to decide if synchronisation events occur and based on an analysis of time indexes and PNCC magnitude values using a clustering approach, a timing synchronisation index is determined.

Claims25

Dependent claims

A method for synchronising a receiver timing to a transmitter timing using a known preamble of a signal, the preamble comprising at least one training sequence, said method comprising:

estimating an absolute value of a cross-correlation metric based on input samples of said signal and samples of said training sequence of said preamble;
estimating a signal power using a short-term average of said estimated absolute value of said cross-correlation metric;
estimating a noise floor power using a delayed long-term average of said estimated absolute value of said cross-correlation metric;
estimating a power normalized cross-correlation metric (PNCC metric) as a function of said estimated signal power and said estimated noise floor power;
deciding that at least one time synchronisation event occurs when at least one first synchronisation criterion is satisfied corresponding to said PNCC metric exceeding a threshold value and storing, for each time a synchronisation event occurs, a magnitude value of said PNCC metric and a corresponding time index;
and
analysing said at least one stored time index and corresponding magnitude values of said PNCC metric to synchronise timing in said receiver to timing in said transmitter, using a timing synchronisation index that is based on at least said at least one stored time index.

4 more elements

An apparatus for synchronising a receiver timing to a transmitter timing using a known preamble of a signal, said preamble comprising at least one training sequence, said apparatus comprising:

a cross-correlator, configured to estimate an absolute value of a cross-correlation metric based on input samples of said signal and samples of said training sequence of said preamble;
a signal power estimator, configured to estimate a signal power using a short-term average of said estimated absolute value of said cross-correlation metric;
a noise floor power estimator, configured to estimate a noise floor power using a delayed long-term average of said estimated absolute value of said cross-correlation metric;
device to estimate a power normalized cross-correlation metric (PNCC metric) as a function of said estimated signal power and said estimated noise floor power;
decision device, configured to decide that at least one time synchronisation event occurs when at least one first synchronisation criterion is satisfied corresponding to said PNCC metric exceeding a threshold value and further configured to store, for each time a synchronisation event occurs, a magnitude value of said PNCC metric and a corresponding time index;
and
analysing device, configured to analyse said at least one stored time indexes and corresponding magnitude values of said PNCC metric to synchronise timing in said receiver to timing in said transmitter, using a timing synchronisation index that is based on at least said at least one stored time index.

4 more elements

Dependencies are inferred from the claim text.

Method and an apparatus for synchronising a receiver timing to transmitter timing

Life of this patent

Method and an apparatus for synchronising a receiver timing to transmitter timing

Life of this patent

Abstract

Claims25