Patent ID: 8559481
Filing Date: 2013-10-15
Classification: H04L

Abstract:
1. 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; 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 lest one stored time index; and updating said threshold with a PNCC threshold value corresponding to the magnitude value of said PNCC metric for each time it is decided that a synchronisation event occurs.