Process for Blind Detection of a Synchronization Signal for LTE

A method of detecting a synchronization signal from a received signal of an Orthogonal Frequency Division Multiplex (OFDM) based communication system, the method comprising the steps of:

• detecting a first primary synchronization signal;
• receiving a signal Y from a communication channel, said vector being a OFDM comprising a set of subcarriers;
• and
• performing a second synchronization detection among a set of M predetermined synchronization sequences Sm, (m=0 to M−1), the second synchronization detection comprising the further steps of:
• for each predetermined sequence Sm, computing a vector Zm from the received signal Y in accordance with the formula Zm[i]=Sm[i]Y[i], where Sm[i], Y[i] and Zm[i] are the element (i) of sequence Sm, the received signal Y and the computed vector Zm, respectively;
• computing a vector Tm by multiplying the symbol in one carrier by the complex conjugate of the symbol in one of the two consecutive carriers;
• and
• maximizing or minimizing a cost function applied on the vector Tm in order to determine the particular sequence offering higher relevance.

A method of detecting a synchronization signal from a received signal of a Long Term Evolution (LTE) communication, the synchronization signal comprising a first short segment Y1=[Y(0), Y(2), Y(4) . . . , Y(60)] and a second interleaved segment Y2=[Y(1), Y(3), Y(5) . . . , Y(61)], the method comprising the steps of:

• (a) computing the element-wise product of Y1 with all possible first short segments S1,m according to Z1,m[i]=S1,m[i]Y[2i], for i=0, . . . , 30;
• (b) multiplying the ith resulting element by the complex conjugate of the i+1-th element, according to T1,m[i]=Z1,m[i]×Z1,m*[i+1], for i=0, . . . , 29;
• (c) selecting the first segment which maximizes
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• (d) identifying the possible second segment in a predetermined table;
• and
• (e) performing steps (a-c) to select the second segment.

An apparatus operative to detect a synchronization signal in an Orthogonal Frequency Division Multiplex (OFDM) based communication system, the apparatus comprising:

• a receiver operative to receive a signal Y from a communication channel, the vector being a OFDM comprising a set of subcarriers;
• a primary detector operative to detect a primary synchronization signal;
• and
• a secondary detector operative to perform a second synchronization detection among a set of M predetermined synchronization sequences Sm (m=0 to M−1), by:
• for each predetermined sequence Sm, computing a vector Zm from the received signal Y in accordance with the formula Zm[i]=Sm[i]Y[i], where Sm[i], Y[i] and Zm[i] are the element (i) of sequence Sm, the received signal Y and the computed vector Zm, respectively;
• computing a vector Tm by multiplying the symbol in one carrier by the complex conjugate of the symbol in one of the two consecutive carriers;
• and
• maximizing or minimizing a cost function applied on the vector Tm in order to determine the particular sequence offering higher relevance.