Method and apparatus for detecting secondary synchronization signal

An apparatus for detecting a secondary synchronization signal, comprising:

• a channel estimation compensation unit, which is configured to calculate a channel estimation compensation value of each sub-carrier of a Secondary Synchronization Signal (SSS) symbol in different Cyclic Prefix (CP) modes or a specified CP mode;
• a half frame coherent accumulation unit, which is connected with the channel estimation compensation unit and is configured to obtain a coherent accumulative result of even half frames and a coherent accumulative result of odd half frames of each sub-carrier according to the channel estimation compensation value of each sub-carrier of said SSS symbol;
• a sequence generation unit, which is configured to generate a SSS sequence;
• a two round detection unit, which is connected with said half frame coherent accumulation unit and said sequence generation unit, and is configured to use the coherent accumulative results of even sub-carriers in the even or odd half frames and the SSS sequences of the even sub-carriers to perform correlation calculation and compute an energy, obtain an index {circumflex over (m)}i of the SSS sequence corresponding to an over-threshold value of a first round detection;
• and determine indexes m0, m1 composing the SSS sequence used in a second round detection according to the index {circumflex over (m)}i, and use coherent accumulative results of all the sub-carriers in the even and odd half frames and SSS sequences of all the sub-carriers to perform collocation correlation calculation and compute an energy, and obtain an over-threshold value of the second round detection, wherein one of m0 and m1 is {circumflex over (m)}i, m1−m0=Δj, and Δj=1, 2, . . . , 7;
• a secondary synchronization signal calculation unit, which is connected with said two round detection unit and is configured to obtain a CP mode according to parameters corresponding to an over-threshold value of the second round detection if the channel estimation compensation unit calculates the channel estimation compensation value of each sub-carrier of the SSS symbol in different CP modes, and calculate a cell Identifier (ID) and a radio frame boundary;
• calculate the cell ID and the radio frame boundary according to parameters corresponding to an over-threshold value of the second round detection if the channel estimation compensation unit calculates the channel estimation compensation value of each sub-carrier of the SSS symbol in the specified CP mode.

A method for detecting a secondary synchronization signal, comprising:

• calculating a channel estimation compensation value of each sub-carrier of a Secondary Synchronization Signal (SSS) symbol in a specified Cyclic Prefix (CP) mode;
• obtaining a coherent accumulative result of even half frames and a coherent accumulative result of odd half frames of each sub-carrier according to the channel estimation compensation value of each sub-carrier of said SSS symbol;
• generating a SSS sequence;
• using the coherent accumulative results of even sub-carriers in the even or odd half frames and the SSS sequences of the even sub-carriers to perform correlation calculation and compute an energy, obtaining an index {circumflex over (m)}i of the SSS sequence corresponding to an over-threshold value of a first round detection, determining indexes m0, m1 composing the SSS sequence used in a second round detection according to the index {circumflex over (m)}i, wherein one of m0 and m1 is {circumflex over (m)}i, m1−m0=Δj, and Δj=1, 2 . . . , 7;
• using coherent accumulative results of all the sub-carriers in the even and odd half frames and SSS sequences of all the sub-carriers to perform collocation correlation calculation and compute an energy, obtaining an over-threshold value of the second round detection;
• and
• calculating a cell Identifier (ID) and a radio frame boundary according to the over-threshold value of the second round detection.