Patent ID: 9065586
Filing Date: 2015-06-23
Classification: H04J,H04L,H04W

Abstract:
1. A method of detecting, among a plurality of modulated carrier signals of different frequencies, at least one of the carrier signals modulated with a tone burst having a tone burst duration, wherein the modulated carrier signals are Global System for Mobile Communications (GSM) carrier signals and the tone burst is contained within a GSM Frequency Correction Channel (FCCH), the method comprising: generating a composite signal comprising the plurality of modulated carrier signals received simultaneously, using a receiver adapted to receive signals in accordance with Third Generation Partnership Project Long Term Evolution specifications; generating samples by sampling the composite signal; dividing the samples of the composite signal into a plurality of blocks, each of the blocks comprising a number of samples corresponding to not more than half of the tone burst duration; transforming the samples of each block into frequency domain components; dividing the frequency domain components of each block into a plurality of groups, each group corresponding to a range of frequencies occupied by a different one of the modulated carrier signals; performing tone burst detection on each group; and determining which of the carrier signals is modulated with the tone burst, according to which of the groups the tone burst is detected in.