Narrowband IoT Primary Synchronization Signal Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless access systems face challenges in efficiently transmitting and receiving data and control information for Narrowband Internet of Things (NB-IoT) user equipment, particularly in generating and synchronizing primary and secondary synchronization signals.
Innovation Solution
A method is provided for generating and transmitting synchronization signals in an NB-IoT system, where a primary synchronization signal (PSS) is repeatedly generated and multiplied by a second sequence, then transmitted through orthogonal frequency division multiplexing (OFDM) symbols, utilizing a bandwidth of one Physical Resource Block (PRB) with 12 subcarriers, to facilitate efficient time and frequency synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If synchronization signals are transmitted using conventional methods in wideband systems, then the system can support traditional wideband user equipment, but it cannot efficiently support narrowband NB-IoT user equipment with limited bandwidth and power
Solution Approach 1:
The patent applies local quality by transmitting the primary synchronization signal only in the central 3 physical resource blocks (frequency range 90-102 subcarriers) rather than across the entire system bandwidth. This localized transmission approach allows NB-IoT user equipment with narrow bandwidth to efficiently receive and process the synchronization signal without requiring full-bandwidth capability, while wider bandwidth systems can still operate normally. The solution tailors the signal transmission to the specific needs of narrowband devices without compromising the overall system architecture.
2Measurement precision
If the primary synchronization signal is transmitted across the entire system bandwidth, then wideband systems can maintain full coverage, but narrowband NB-IoT user equipment cannot efficiently receive and process the signal
Solution Approach 1:
The patent concentrates the primary synchronization signal transmission in a localized frequency region (central 3 physical resource blocks) rather than distributing it across the entire system bandwidth. This allows NB-IoT user equipment to receive the synchronization signal using a narrow bandwidth, significantly reducing power consumption while maintaining adequate synchronization accuracy. The localized transmission ensures that narrowband devices can efficiently process the signal without expending excessive energy on wideband reception.
Solution Approach 2:
The patent transmits the primary synchronization signal before other downlink signals in the frame structure (in the first slot of each subframe). This preliminary transmission allows NB-IoT user equipment to acquire synchronization information early, enabling them to configure their reception parameters and subsequently receive other downlink signals more efficiently with optimized power consumption. The early transmission provides a foundation for energy-efficient operation throughout the communication session.
3Reliability
If conventional synchronization signal generation methods are used, then traditional systems can achieve adequate synchronization, but NB-IoT user equipment cannot actively synchronize with the base station
Solution Approach 1:
The patent transmits the primary synchronization signal in the first slot of each subframe, before other downlink signals. This preliminary action enables NB-IoT user equipment to acquire time and frequency synchronization early in the frame structure, establishing a reliable foundation for subsequent data transmission and reception. With synchronization achieved beforehand, the system can proceed with efficient data transmission without delays or retransmissions, thereby improving overall productivity while maintaining high synchronization reliability.
Data Source
AI summary
The present invention provides a method and devices for transmitting and receiving a synchronization signal and a method for generating a synchronization signal in a wireless access system supporting narrowband Internet of Things (NB-IoT). A method for transmitting a primary synchronization signal (PSS) by a base station in a wireless access system supporting narrowband Internet of Things (NB-IoT), according to an embodiment of the present invention, can comprise the steps of: repeatedly generating first sequences n times so as to generate primary synchronization signals; multiplying n first sequences by second sequences and thus generating n primary synchronization signals; and transmitting n primary synchronization signals by means of n OFDM symbols, respectively. The size of a bandwidth used in the wireless access system supporting NB-IoT is the size of one physical resource block (PRB), and one PRB can comprise twelve subcarriers in a frequency domain.