With the wider usage of mobile applications like cloud services, social networking and point to point video/file sharing, uplink traffic load is becoming much heavier, and LTE uplink throughput improvement tends to be an essential and practical requirement for operators. LTE uplink is interference limited in typical networks, and co-channel interference has substantial impact on uplink cell average and cell edge throughput. Base station (BS) MMSE-IRC receiver can bring in significant SINR gain over MMSE receiver by suppressing the inter-cell interference, in both homogeneous and heterogeneous networks, as concluded in TR 36.884. The RAN4 demodulation performance requirements for BS MMSE-IRC receiver are completed at RAN #72 meeting in June 2016 [3] [4]. Further evolution of BS receiver, such as interference cancellation (IC) receiver, can be considered to mitigate the intra-cell inter-user interference. In the intra-cell inter-user interference scenario where multiple users are co-scheduled on the same resource elements, BS IC receiver is expected to achieve noticeable throughput gain for cell centre and cell edge users. Note that the utilization of BS IC receiver is transparent to the users, and the performance gain of BS IC receiver can also be enjoyed by legacy users. To study the performance benefits of BS IC receiver, a new study item "Study on interference cancellation receiver for LTE BS" was approved at RAN #73 [5], and the current document summarizes the study done under this study item.

The study item should fulfil the following objectives:

• Identify the target deployment scenarios and the co-channel intra-cell interference conditions. The following scenario is to be considered:
  • Intra-cell inter-user interference scenario where multiple users are co-scheduled on the same resource elements.
• Identify the reference receiver structures for PUSCH
  • Receiver structures based on interference cancellation is considered as a starting point, and practical and realizable implementation should be taken into account.
• Agree on the interference models, interference levels and simulation parameters for link level evaluations
• Evaluate the link-level gain for PUSCH over baseline receiver
  • Evaluate the link-level gain over baseline Rel-8 MMSE receiver for intra-cell inter-user interference scenarios.
  • The prioritization of number of Rx antennas will be discussed and decided in study phase.