NB-IoT SC-PtM Multicast Transmission via Dual Search Space Segmentation
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Solution Overview
Problem
Current wireless communication systems, particularly those supporting NarrowBand-Internet of Things (NB-IoT), face challenges in efficiently transmitting and receiving multicast and broadcast signals due to limited time and frequency resources, leading to potential signal overlap and restricted control information capacity.
Innovation Solution
A method for transmitting and receiving data in NB-IoT systems using a Single Cell-Point to Multipoint (SC-PtM) scheme, where the Narrowband Physical Downlink Control Channel (NPDCCH) and Narrowband Physical Downlink Shared Channel (NPDSCH) are configured to carry Multicast Control Channel (MCCH) and Multicast Traffic Channel (MTCH) information, allowing for efficient resource scheduling and transmission across multiple frequency resources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multicast and broadcast signals are transmitted using existing NB-IoT resources, then resource utilization is improved, but signal overlap and control information capacity are restricted
Solution Approach 1:
The patent segments the control channel monitoring process into two distinct search spaces: a first search space for legacy NB-IoT control channels and a second search space for multicast control channels. This segmentation allows different types of control information to be monitored separately, preventing signal overlap while utilizing existing NB-IoT resources efficiently.
Solution Approach 2:
The patent introduces a group identifier as an intermediary element that links the multicast traffic channel to the control channel. The group identifier is used to monitor the second search space and establishes a correspondence relationship between control channel monitoring and multicast service reception, enabling efficient resource utilization without causing signal conflicts.
2Adaptability or versatility
If control information capacity is increased to support multicast services, then service capability is improved, but device complexity increases
Solution Approach 1:
The patent makes existing NB-IoT physical channels multi-functional by enabling the NPDCCH and NPDSCH to serve both traditional unicast purposes and new multicast purposes. The first search space handles legacy control information while the second search space handles multicast control information, allowing the system to support multiple services without adding entirely new channel structures.
Solution Approach 2:
The patent performs preliminary configuration of the second search space and group identifier before multicast service activation. The network configures the UE with the second search space parameters and group identifier in advance, so that when multicast services are activated, the UE is already prepared to monitor the appropriate control channels, reducing operational complexity.
Data Source
AI summary
The present invention discloses a method for transmitting/receiving data in a wireless communication system supporting NB-IoT and a device for the method. More specifically, the method comprises monitoring a first search space configured for a first NPDCCH, wherein the first NPDCCH includes first control information for scheduling a first NPDSCH carrying an SC-MCCH; receiving the first NPDSCH based on the first control information; monitoring a second search space configured for a second NPDCCH by using a group identifier acquired through the SC-MCCH, wherein the second NPDCCH includes second control information for scheduling a second NPDSCH carrying an SC-MTCH; and receiving the second NPDSCH based on the second control information, wherein the second NPDCCH and the second NPDSCH are transmitted on one carrier, and carrier configuration information representing the one carrier is carried through the SC-MCCH.