Patent ID: 7864899

Claim:
A method in user equipment, comprising: communicating in one or more allocated time slots at a given frequency with a first base station; searching for a frequency correction channel in a signal received from a second base station using two adder blocks, one for each alternate idle frame pair; tuning to a frequency at which the second base station with which the user equipment does not have connection is transmitting the signal, when a last allocated time slot before an idle frame has elapsed; receiving a frame format signal transmitted by the second base station; correlating the received signal with a reference signal; summing correlation results over a given time period in an adder block of the two adder blocks as a summing value; and comparing the sum with a given reference value and, if the sum exceeds the reference value, determining that the frequency correction channel has been detected, storing a position of the frequency correction channel and exiting the process, otherwise, continuing correlation and comparison until the idle frame ends, retaining the summing value in the adder block, tuning back to the frequency used by the first base station, and continuing the above process in every other idle frame.