Patent ID: 8576869

Claim:
A method in a radio receiver for simultaneously detecting a cell group and a cyclic prefix (CP) length in a Long Term Evolution (LTE) radio access network, the method comprising the steps of: determining a primary synchronization signal (P-SyS) timing; determining secondary synchronization signal (S-SyS) timings for a long CP and a short CP from the determined P-SyS timing; placing a single Fast Fourier Transform (FFT) window for the S-SyS between the determined timings for the long CP and the short CP and performing an FFT to obtain a frequency domain transformed S-SyS; performing a first phase shift of the frequency domain transformed S-SyS for the long CP to generate a first version of a phase shifted frequency domain transformed S-SyS; performing a second phase shift of the frequency domain transformed S-SyS for the short CP to generate a second version of the phase shifted frequency domain transformed S-SyS; correlating all S-SyS sequences that can occur in the LTE network to both the first and second phase shifted versions of the frequency domain transformed S-SyS; and detecting a correlation between one of the S-SyS sequences and the phase shifted versions of the frequency domain transformed S-SyS that provides maximum energy, thereby determining the cell group and the CP length.