Edge user performance improvement solution based on multi-point coordination CoMP

1. Project Background

The 5G communication network adopts a multi-site cellular layout to achieve continuous coverage. There are naturally a large number of edge areas between cells. Limited by many factors such as coverage distance/bandwidth/number of antennas/terminal capabilities, interference in the edge areas of cells is prominent, and user perception is poor and spectrum efficiency is low. There is a natural problem of uneven service quality between the center and the edge, which brings many challenges to user experience and network operation and maintenance.

In the early stage, some local areas have deployed basic CoMP multi-point coordination technology to eliminate interference in edge areas and improve network performance, but there is still room for further improvement in performance optimization, etc. For example, FNR macro stations have high interference in multiple cells, the uplink and downlink coverage of macro and micro networks is asymmetric, resulting in weak coverage or many blind spots in buildings, and the downlink joint transmission has low combining gain due to phase differences.

The current solution is based on the CoMP collaborative technology implemented in the first phase, and evolves into a user-centric seamless mobility network with the help of macro-micro collaborative UL Only TRP (Transmit-Receive Point), uplink joint equalization JE (Joint Equalization), 1+N specification CoMP JR (Joint Reception), downlink CJT (Coherent Joint Transmission) and other technologies.

This solution is based on the following CoMP collaboration technologies implemented in the first phase:

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2. Application scenarios and benefits

• Applicable scenarios:
  Overlapping coverage area of ​​multiple cells on the same frequency; uplink PRB utilization rate is less than 30%, and downlink PRB utilization rate is less than 10%.
• Network Gain:
  Uplink benefits: The uplink rate of macro and micro edge users is increased by more than 20%. Under the FNR standard, in high NI interference scenarios, interference is suppressed and uplink reception performance is improved.
  Downlink benefits: Improve the spectrum efficiency and service experience of downlink users. After the function is enabled, the downlink rate gain of edge users can be increased by 20%+.

3. Key technologies

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4. Deployment Effect

• After the uplink UL only TRP function was enabled in the macro and micro scenarios, three groups were almost verified, and the single UE-level uplink rate gain was 20%~50%.
• After the FNR macro base station turns on the JE superimposed 1+N specification JR function, the single UE-level uplink rate gain in high-interference scenarios is 40%+.
• After the TNR macro base station enabled the downlink CJT function, two groups of fixed-point verifications were carried out, and the downlink rate gain was 20%~35%.

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The KPI benefits after large-scale deployment are as follows:

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5. Technological evolution

At the current stage, CoMP collaboration needs to evolve from a "cell-centric" to a "user-centric" imperceptible mobility network, and build a user-centric network (U-Net). Through deep collaboration among multiple cells and elimination of interference and switching problems caused by cell boundaries, the terminal can finally move freely without perception, ensuring a steady-state user experience. In order to smoothly evolve to 6G, the collaboration of time-frequency-space-energy domains is realized, and preparations are made to establish a new form of networking.

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