Simultaneous cell group and cyclic prefix detection method, apparatus and system
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorsLeif Wilhelmsson, Bengt Lindoff
Life of this patent
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Abstract
A method, and associated apparatus and system, for simultaneous cell group and cyclic prefix (CP) detection, having the steps of determining primary synchronization signal (P-SyS) timing τ using the P-SyS; based on τ, determine a secondary synchronization signal (S-SyS) timing; placing a single Fast Fourier Transform (FFT) window; FFT processing the signal to obtain the frequency domain S-SyS symbols; equalizing the frequency domain S-SyS signal; phase correcting the S-SyS signal; and detecting the cell group and CP length by the correlation giving maximum energy.
Claims4
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.
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 receiver comprising:
- cell search means for determining a primary synchronization signal (P-SyS) timing;
- cell search means for determining a secondary synchronization signal (S-SyS) timing for a long CP and a short CP from the determined P-SyS timing;
- means for placing a single Fast Fourier Transform (FFT) window between the timing for the long CP and the short CP and for performing an FFT to obtain a frequency domain transformed S-SyS;
- means for 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;
- means for 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;
- means for 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
- means for 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.
Dependencies are inferred from the claim text.