by TIP News

Last month, TIP awarded two silver badges for the RAN Intelligence & Automation (RIA) subgroup. Aira Technologies was awarded a silver badge for RIA Use Case 2: Uplink Channel Estimation and AirHop Communications was awarded a silver badge for testing and validating RIA Use Case 11: PCI Configuration and Optimization.

RIA Use Case 2: Uplink Channel Estimation is based on how Artificial Intelligence and Machine Learning can be used to reduce overhead and improve user performance by predicting Sounding Reference Signals. More accurate and efficient channel estimation will also allow beamforming improvements in Massive MIMO scenarios. In TDD, uplink channel estimation is used to accurately determine beamforming weights in the downlink. Uplink channel estimation is usually done based on Sounding Reference Signals (SRS), available in both LTE and 5G NR. For efficiency reasons, SRS are not available in every transmission slot, which degrades channel estimation, especially under mobility. Thus, the possibility to properly predict SRS in advance based on appropriate AI techniques or ML algorithms is a great asset to reduce overhead.


Figure 1 UC2: Uplink Channel Estimation Test Setup


Aira Technologies has developed an ML/AI-based xApp that reads the SRS Channel estimates from the Distributed Unit (DU) over the E2 interface. The xApp is developed to detect the channel evolution for users and calculate Massive MIMO beam forming weights based on channel prediction. The xApp was tested in Menlo Park and the testing platform included an End-to-End setup with a VMWare RIC and a VIAVI TM500 UE emulator. A Foxconn Radio Unit (RU) and a Capgemini Central Unit (CU) were also part of the testing platform.


Figure 2 High-Level results of Testing Aira’s xApp


When testing the xApp, the channel estimates of the SRS signal based on the AI/ML algorithm resulted in a 2x improvement of the Mean Square Error (MSE) that translated into a 4dB improvement of the SINR. TIP’s technical committee reviewed the test results and awarded Aira Technologies a Silver Badge. For more information, see the detailed test report in TIP Exchange.

View the white paper here