Uplink Signal Codeword Cover Multiplexing in NB-IoT
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Solution Overview
Problem
Current wireless communication systems face challenges in managing explosive data traffic, increasing transfer rates, and reducing latency while maintaining energy efficiency, particularly in supporting a large number of connections and avoiding inter-cell interference in NB-IoT systems.
Innovation Solution
The method involves using an orthogonal codeword cover generated by a DFT matrix for multiplexing between user equipment (UEs) and allocating codewords based on coverage classes to minimize inter-cell interference, along with frequency hopping for efficient uplink signal transmission in NB-IoT systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If orthogonal codeword cover is used for multiplexing multiple UEs, then system capacity and resource utilization are improved, but inter-cell interference increases
Solution Approach 1:
The patent applies local quality by allocating different orthogonal codeword covers to different coverage classes of UEs. Specifically, UEs in coverage enhancement mode select codeword covers from a first set, while UEs in normal mode select from a second set. This localized differentiation based on coverage class reduces inter-cell interference while maintaining high system capacity for multiplexing.
Solution Approach 2:
The patent segments the codeword cover resources into multiple sets corresponding to different coverage classes. By dividing the overall resource pool into distinct segments for different UE types, the system achieves fine-grained resource allocation that improves multiplexing capacity while controlling interference through targeted resource isolation.
2Reliability
If frequency hopping is implemented for uplink transmission, then resistance to fading and interference is improved, but device complexity increases
Solution Approach 1:
The patent implements frequency hopping by dynamically changing the frequency parameter of uplink transmissions across different time slots. The UE transmits on different frequencies in different slots according to a hopping pattern, which provides diversity against fading and interference. This parameter-based approach achieves reliability improvement with relatively simple implementation.
Data Source
AI summary
Provided are a method of transmitting, by a user equipment, a uplink signal in a wireless communication system. The method includes receiving control information related to a codeword cover used for a multiplexing of a multiple of user equipments from a base station, generating a transmission symbol of a specific length by repeating a data symbol in a specific time unit, generating the uplink signal by applying the codeword cover of the specific length to the generated transmission symbol, and transmitting the generated uplink signal to the base station through a single tone.