Large scale system evaluations using PHY abstraction for LTE with OpenAirInterface

In this paper we present the complete methodology of expected effective SINR mapping (EESM) and mutual information effective SINR mapping (MIESM) based PHY abstraction for OpenAirInterface (OAI) LTE platform. The methodology consists of calibration of the ESM techniques using OAI link level simulator and then the validation of calibrated scheme on the OAI system level simulator. We present the methodologies for different transmission modes of LTE including transmission mode 1, 2 and 6 employing single-input single-output (SISO) channel, multiple-input single-output (MISO) channel with transmit precoding and transmit beamforming techniques respectively. We show that the calibration of PHY abstraction is a necessary step for these transmission modes and if properly calibrated then both of the ESM techniques can be used equivalently. Further we show with the help of results that the implemented PHY abstraction in the OAI system level simulator provides the speed in simulation time by a factor of 30 while providing the same accuracy as with the full PHY implementation. Since all the simulations are performed with OAI simulator which implements the LTE release 8.6 therefore our presented results provide portability for other LTE simulators as well.