Apparatus and method for cell detection by combining secondary spreading sequences

A method, comprising:

• receiving repetitions of a synchronization signal (SS), the SS comprising a plurality of SS blocks, and each SS block comprising at least a primary spreading signal (PSS) and a secondary spreading signal (SSS);
• identifying timing of the SS using a strongest received PSS;
• identifying tentative SSSs based on the identified timing of the SS;
• grouping the tentative SSSs that can be grouped based on the identified timing of the SS and a defined timing pattern of the repetitions of the SS;
• cross correlating the SS with an SSS code book to locally generate SSS candidates;
• cross correlating each tentative SSS with the locally generated SSS candidates to generate cross correlated outputs;
• combining the cross correlated outputs with respective weights for each group of the tentative SSSs:
• determining an SSS as the tentative SSS with a maximum combined cross correlation output;
• and
• determining a cell identification (ID) based on the determined SSS.

An apparatus, comprising:

• a processor configured to:
• receive repetitions of a synchronization signal (SS), the SS comprising a plurality of SS blocks, and each SS block comprising at least a primary spreading signal (PSS) and a secondary spreading signal (SSS);
• identify timing of the SS based on a strongest received PSS in the SS,
• identify tentative SSSs based on the identified timing of the SS, and
• group n tentative SSSs into each of n groups based on the identified timing of the SS and a defined timing pattern of the repetitions of the SS, where n is an integer;
• a register configured to receive the SS;
• n×n SSS correlators, where each of the n SSS correlators is connected to one of the n tentative SSSs in one of the n groups and includes SSS candidates locally generated by cross correlating the SS with an SSS code book;
• n×n multipliers, where each of the n multipliers is connected to one of the n SSSs correlators and receives a weight;
• and
• n adders, where each of the n adders is connected to n of the n SSSs multipliers associated with one of the n groups, respectively, where an output of each of the n adders is connected to the processor,
• wherein the processor is further configured to determine an SSS as the tentative SSS with a maximum output of the n adders, and determine a cell identification based on the determined SSS.