MBSFN Subframe PDCCH Extension for Relay Node Resource Utilization
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Solution Overview
Problem
In LTE wireless communication systems, the use of relay nodes leads to inefficient resource utilization in MBSFN subframes, particularly due to the requirement for Rel 8 UAs to receive control information on each subframe, resulting in wasted resources as the relay node cannot transmit and receive simultaneously at the same frequency, and this inefficiency is exacerbated by the limited allocation of resource elements (REs) for control channels.
Innovation Solution
The relay node optimizes resource allocation by assigning additional REs in the PDCCH of the MBSFN subframe for transmitting additional control information, including reference signals, DL grants, and synchronization signals, allowing for improved resource utilization and supporting both Rel 8 and Rel 10 UAs without impacting existing configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If relay nodes transmit control information in MBSFN subframes using traditional PDCCH allocation, then Rel 8 UAs can receive control information, but resource utilization becomes inefficient due to inability to transmit and receive simultaneously at the same frequency
Solution Approach 1:
The patent extends the PDCCH into the MBSFN data region by utilizing unused resource elements (REs) that were previously allocated for data transmission. This dimensional extension allows control information to be transmitted without conflicting with the relay node's reception operations, thereby improving resource utilization while maintaining reliable control information delivery to Rel 8 UAs.
Solution Approach 2:
The patent makes the PDCCH multi-functional by allowing it to serve both Rel 8 UAs (which require control information on every subframe) and Rel 10 UAs (which can operate without control information in MBSFN subframes). The unused REs in the MBSFN subframe are repurposed to carry additional control information, enabling the system to support multiple UE types simultaneously without sacrificing resource efficiency.
2Productivity
If additional resource elements are allocated for control channels in MBSFN subframes, then resource efficiency improves, but device complexity increases due to need to support both Rel 8 and Rel 10 UAs
Solution Approach 1:
The patent applies local quality by assigning different functions to different regions of the MBSFN subframe. The first portion maintains traditional PDCCH allocation for Rel 8 UA compatibility, while the unused REs in the data region are locally repurposed for additional control information. This localized adaptation allows the system to improve resource efficiency without requiring global reconfiguration or impacting existing Rel 8 operations.
Solution Approach 2:
The patent performs preliminary action by pre-identifying and reserving unused resource elements in the MBSFN subframe before data transmission begins. These unused REs are预先 allocated for control information transmission, allowing the system to efficiently support both Rel 8 and Rel 10 UAs without requiring complex dynamic resource allocation or increasing device complexity.
3Productivity
If unused resource elements are utilized for additional control information, then spectrum efficiency increases, but measurement precision requirements increase for channel estimation and mobility measurements
Solution Approach 1:
The patent introduces reference signals as intermediary elements that facilitate accurate channel estimation and mobility measurements in the extended PDCCH region. These reference signals are transmitted using the unused REs alongside the additional control information, providing reliable measurement points that maintain measurement precision while enabling spectrum efficiency improvements through the utilization of previously wasted resources.
Data Source
AI summary
A relay node comprising a processor configured such that the relay node transmits a multicast/broadcast single frequency network (MBSFN) subframe including a control portion without a data portion, wherein the control portion comprises additional information assigned to any available resource elements (REs). Also included is a user agent (UA) comprising a processor configured such that the UA receives a MBSFN subframe including a control portion without a data portion, wherein the control portion comprises additional information assigned to any available REs. Also included is a method of wireless communication comprising transmitting a MBSFN subframe including a control portion without a data portion, wherein the control portion comprises additional information assigned to any available REs. Also included is a method of wireless communication comprising receiving a MBSFN subframe including a control portion without a data portion, wherein the control portion comprises additional information assigned to any available REs.