Time reference identification method

1. A method of identifying a time reference in a signal received from a transmitter of a communications network, including:

generating a replica of a synchronization sequence on the basis of at least one known transmission parameter;

comparing the replica of the synchronization sequence to a sequence derived from the signal received from the transmitter of the communications network to identify a reference point, as the time reference, in the signal received from the transmitter of the communications network;

wherein:

the signal received includes one or more signals on a plurality of subcarriers and one or more transmission parameters including:

a pilot channel symbol position;

a scrambling code of the signal; and

a subcarrier map of the signal;

wherein generating the replication of the synchronization sequence comprises:

generating a partial synchronization sequence replica for each subcarrier to be received; and

combining the partial synchronization sequence replicate for each subcarrier into a single synchronization sequence replica.

2. The method of identifying the time reference in the signal received from the transmitter of the communications network according to claim 1 wherein the at least one known transmission parameter was derived from a previous communication with the communications network.

3. The method of identifying the time reference in the signal received from the transmitter of the communications network according to claim 1 wherein the step of comparing the replica of the synchronization sequence to a sequence derived from the signal received, includes, combining the replica of the synchronization sequence with the sequence derived from the signal received on a sample by sample basis to determine a peak correlation value between the sequences.

4. The method of identifying the time reference in the signal received from the transmitter of the communications network according to claim 3 wherein in the event that the peak correlation value exceeds a predetermined threshold, the method includes identifying the time position of the peak as the time reference in the signal received.

5. A method of synchronizing a receiver with the communications network, including:

identifying the time reference in the signal received from the transmitter using the method according to claim 1 ;

synchronizing the receiver timing with reference to the identified time reference.

6. A method, in a mobile terminal communicating with the communications network, including:

attempting to perform synchronization with the communications network in accordance with claim 5 ; and

in the event that synchronization fails, attempting synchronization with the communications network using an alternative method.