MSG3 NPUSCH Transmission Through OCC-Multiplexed NPRACH
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Solution Overview
Problem
Wireless communication systems face challenges in improving communication flexibility and efficiency, particularly in non-terrestrial networks (NTN) where IoT devices experience frequent preamble collisions and require more repetitions due to long distances and large coverage areas, leading to inefficiencies in NPRACH transmissions.
Innovation Solution
Implementing orthogonal cover code (OCC) multiplexing methods for NPRACH and NPUSCH transmissions, including intra-repetition, inter-repetition, and combined OCC methods, along with indicating OCC indexes in NPDCCH DCI format N1 or MAC CE to resolve collisions and enhance uplink capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If NPRACH transmissions use traditional methods without OCC multiplexing, then the system is simpler to implement, but preamble collisions occur frequently and uplink capacity is limited
Solution Approach 1:
The patent segments the uplink transmission resources by introducing orthogonal cover codes that divide the NPRACH preamble space into multiple orthogonal segments. Each preamble can be assigned a unique OCC index, creating segmented resource pools that reduce collisions while maintaining structured organization for reliable detection
Solution Approach 2:
The patent changes the parameter space by introducing OCC indexes as an additional dimension for resource identification. This parameter change transforms the single-dimensional preamble resource allocation into a multi-dimensional space, enabling more preambles to be distinguished without increasing time-frequency resource usage
2Area of stationary object
If more repetitions are used for NPRACH transmissions in NTN, then coverage is improved for long distances, but transmission time and resource consumption increase
Solution Approach 1:
The patent uses orthogonal cover codes to create multiple copies of the same preamble resource in the code domain rather than requiring additional time-frequency copies. This allows the same physical resources to serve multiple users through code division, expanding effective coverage without proportionally increasing transmission time
3Adaptability or versatility
If OCC multiplexing is implemented for NPUSCH, then uplink capacity and flexibility are improved, but system complexity and implementation difficulty increase
Solution Approach 1:
The patent creates a universal OCC multiplexing framework that can be applied across different NPUSCH transmission scenarios including Msg3, data transmissions, and retransmissions. The same OCC indexing mechanism serves multiple functions: collision avoidance, resource identification, and multiplexing, reducing the need for separate mechanisms for each scenario
Data Source
AI summary
An internet of things (IoT) non-terrestrial network (NTN) device user equipment (UE) is described. The UE includes receiving circuitry configured to receive narrowband physical random access channel (NPRACH) configurations including NPRACH resource configuration, repetition parameters, orthogonal cover code (OCC) multiplexing methods and OCC multiplexing factors. The receiving circuitry may also be configured to receive a narrowband physical downlink control channel (NPDCCH) downlink control information (DCI) format N1 and cyclic redundancy check (CRC) scrambled by a random access-radio network temporary identifier (RA-RNTI) for random access response (RAR) in an RA response window. The UE also includes transmitting circuitry configured to select an NPRACH resource, randomly select an OCC index for an OCC multiplexing, transmit NPRACH preambles with a configured OCC multiplexing method and a multiplexing factor, determine a narrowband physical uplink shared channel (NPUSCH) resource for msg3, and transmit a msg3 NPUSCH on the determined NPUSCH resource.