Non-coherent neighbor cell searching method

摘要

The present invention relates to a non-coherent neighbor cell search method for primary synchronization signal (PSS) and secondary synchronization signal (SSS). In order to eliminate the channel response of the home cell, the present invention utilizes the similarity of channel responses at adjacent subcarriers, components at the kth subcarrier and the (k+1)th subcarrier of the received signal are respectively multiplied by the conjugation of the corresponding local synchronization signal to respectively obtain the kth product and the (k+1)th product. Afterward, a combination signal is obtained by examining the difference of the kth product and the (k+1)th product. By mathematical simplification and analysis, the main unknown component of the combination signal is the synchronization signal of neighbor cell, also in a compound form. Thus, the neighbor cell ID can be obtained by performing the correlation operation of the combination signal to the compound reference sequence.

主权项

1. A non-coherent neighbor cell search method, adapted for a user equipment (UE), wherein the UE communicates through a home cell, the non-coherent neighbor cell search method comprising:
decoding a home cell identification (ID) by the UE; obtaining components at a kth subcarrier and a (k+1)th subcarrier of a received signal by the UE; multiplying the component at the (k+1)th subcarrier of the received signal by a conjugation of a component at a (k+1)th subcarrier of a local synchronization signal by the UE, for removing the local synchronization signal from the component at the (k+1)th subcarrier of the received signal, to obtain a first product, wherein the local synchronization signal is a synchronization signal that corresponds with the home cell ID; multiplying the component at the kth subcarrier of the received signal by the conjugation of a component at a kth subcarrier of the local synchronization signal by the UE, for removing the local synchronization signal from the component at the kth subcarrier of the received signal, to obtain a second product; calculating a difference between the first product and the second product by the UE, for removing a home cell channel response signal, to obtain a combination signal; and performing a correlation operation between the combination signal and all possible sequences associated with all possible IDs of neighbor cells by the UE so as to obtain a neighbor cell ID; wherein the UE can successfully switch and connect a specific neighbor cell from the home cell by the neighbor cell ID obtain from the correlation operation when the UE is close to the specific neighbor cell; and wherein k is an integer.