Lite UE Narrowband SIB-L Access for Wide Bandwidth Cells
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Solution Overview
Problem
Low-cost Machine-Type Communications (MTC) devices face challenges in understanding the physical downlink control channel (PDCCH) and decoding system information blocks (SIBs) due to their narrow bandwidth transmission/reception capabilities, which limits their access to cells with wider system bandwidth.
Innovation Solution
A lite user equipment (UE) configured to receive a physical broadcast channel (PBCH) in a reduced bandwidth, processing it to acquire system information blocks (SIBs) and determine the location of a lite SIB (SIB-L) and lite physical downlink control channel (L-PDCCH), enabling efficient communication in wireless communication systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If lite UE uses narrow bandwidth transmission/reception, then device cost and complexity are reduced, but ability to access cells with wider system bandwidth is limited
Solution Approach 1:
The system segments the bandwidth access process into two parts: initial access using narrow bandwidth (matching lite UE capabilities) and subsequent information acquisition using wide bandwidth resources. The PBCH and SIB-L are transmitted in narrow bandwidth for initial access, while other SIBs are transmitted in wide bandwidth and scheduled by L-PDCCH, allowing lite UEs to progressively access wider bandwidth resources without requiring full bandwidth capability from the start.
Solution Approach 2:
The L-PDCCH (lite Physical Downlink Control Channel) acts as an intermediary that bridges the narrow bandwidth initial access and wide bandwidth data transmission. It schedules the transmission of other SIBs in wide bandwidth resources, enabling lite UEs to access wide bandwidth information indirectly through the control channel that is initially accessible in narrow bandwidth.
2Loss of information
If lite UE processes full system information in wide bandwidth, then complete system information is acquired, but processing complexity and energy consumption increase
Solution Approach 1:
System information is segmented into two categories: essential information (SIB-L) transmitted in narrow bandwidth that lite UEs must process, and additional information (other SIBs) transmitted in wide bandwidth that is scheduled by L-PDCCH. This segmentation allows lite UEs to process only the minimal essential information in narrow bandwidth while having access to complete system information through the scheduled wide bandwidth transmissions, reducing mandatory processing energy while maintaining information completeness.
Solution Approach 2:
The system transmits more system information (other SIBs) in wide bandwidth than lite UEs initially need, but schedules these transmissions through L-PDCCH which lite UEs can decode in narrow bandwidth. This partial action approach ensures complete information availability while allowing UEs to process only what is scheduled and necessary, avoiding the need to continuously monitor and process all wide bandwidth transmissions.
3Loss of information
If network transmits all SIBs in wide bandwidth, then complete system information is provided, but lite UEs with narrow bandwidth cannot decode them
Solution Approach 1:
System information transmission is segmented into SIB-L (essential information) in narrow bandwidth and other SIBs (additional information) in wide bandwidth. The SIB-L contains critical access and configuration information that lite UEs can decode with narrow bandwidth, while other SIBs provide supplementary information scheduled by L-PDCCH, ensuring both narrow and wide bandwidth UEs can access appropriate information.
Solution Approach 2:
The L-PDCCH serves as an intermediary control channel that schedules wide bandwidth SIB transmissions. Since L-PDCCH itself is accessible in narrow bandwidth for lite UEs, it mediates the delivery of wide bandwidth information by providing scheduling instructions that narrow bandwidth devices can decode, thereby enabling indirect access to wide bandwidth system information.
Data Source
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AI summary
A network and user equipment are configured to support machine type communications is provided. The UE includes processing circuitry to process a physical broadcast channel (PBCH) to acquire at least one system information block (SIB). The processing circuitry also processes the at least one SIB to determine a location of a lite SIB (SIB-L). The processing circuitry determines a location of a lite physical downlink control channel (L-PBCCH) from the SIB-L.