Method for signal synchronization in ofdm based nb-iot system

A method for signal synchronization in Orthogonal frequency-division multiplexing (OFDM) based Narrow Band-Internet of Thing (NB-IoT) system, comprising:

• receiving, by a User Equipment (UE) (200), a New Radio-Narrowband Primary Synchronization Signal (NR-NPSS) subframe comprising a NR-NPSS transmitted by a base station (BS) (100), wherein the NR-NPSS comprises a plurality of Zadoff-Chu sequences of length 11, wherein all the 14 Zadoff-Chu sequences are used to obtain time and frequency synchronization in the NB-IoT system;
• generating, by the UE (200), a reference NR-NPSS, wherein the reference NR-NPSS comprises 14 Zadoff-Chu sequences each of which is of length 11, wherein all the 14 Zadoff-Chu sequences are used to obtain time and frequency synchronization in the NB-IoT system;
• mapping, by the UE (200), each of the 14 Zadoff-chu sequences of the reference NR-NPSS to resource elements of each OFDM symbol of 14 OFDM symbols in an NR-NPSS subframe;
• and
• detecting, by the UE (200), the NR-NPSS from the received NR-NPSS subframe using the reference NR-NPSS to obtain the time and frequency synchronization in the NB-IoT system.

A base station (100) for signal synchronization in a through a Narrow Band-Internet of Thing (NB-IoT) system, comprising:

• a memory (110);
• a processor (120);
• and
• a New Radio-Narrowband Primary Synchronization Signal (NR-NPSS) circuit (140), coupled to the memory and the processor, configured to:
• generate a New Radio-Narrowband Primary Synchronization Signal (NR-NPSS), wherein the NR-NPSS comprises 14 Zadoff-Chu sequences each of which is of length 11, wherein all the 14 Zadoff-Chu sequences are used to obtain time and frequency synchronization in the NB-IoT system;
• map each Zadoff-chu sequence of the 14 Zadoff-chu sequences of the NR-NPSS to resource elements of each OFDM symbol of 14 OFDM symbols in an NR-NPSS subframe;
• and
• transmit the NR-NPSS subframe comprising the mapped NR-NPSS to at least one User Equipment (UE) (200).

A User Equipment (UE) (200) for signal synchronization in a through a Narrow Band-Internet of Thing (NB-IoT) system, comprising:

• a memory (210);
• a processor (220);
• and
• a New Radio-Narrowband Primary Synchronization Signal (NR-NPSS) circuit (240), coupled to the memory and the processor, configured to:
• receive a New Radio-Narrowband Primary Synchronization Signal (NR-NPSS) subframe comprising a NR-NPSS transmitted by a base station (100) (BS), wherein the NR-NPSS comprises a plurality of Zadoff-Chu sequences of length 11, wherein all the 14 Zadoff-Chu sequences are used to obtain time and frequency synchronization in the NB-IoT system;
• generate a reference NR-NPSS, wherein the reference NR-NPSS comprises 14 Zadoff-Chu sequences each of which is of length 11, wherein all the 14 Zadoff-Chu sequences are used to obtain time and frequency synchronization in the NB-IoT system;
• map each of the 14 Zadoff-chu sequences of the reference NR-NPSS to resource elements of each OFDM symbol of 14 OFDM symbols in an NR-NPSS subframe;
• and
• detect the NR-NPSS from the received NR-NPSS subframe using the reference NR-NPSS to obtain the time and frequency synchronization in the NB-IoT system.