LTE-A Relays and Repeaters May 20, 2008 R1-101491 3GPP TSG-RAN WG1 #60 22nd - 26th February, 2010 San Francisco, US Link Analyses of SU-MIMO Operation for UL of LTE-A with Agreed Simulation Assumptions Agenda item : 7.3.1 Source : Qualcomm Inc Document for : Discussion and Decision

Introduction Background In 3GPP RAN1#58bis, the following were concluded for further alignment of simulation parameters in studies of layer shifting + ACK Bundling for UL SU-MIMO: - Provide correlation statistics of error events of two TBs The throughput results should be accompanied by the assumptions on the respective BLER targets of 2 CWs Composite UL-CQI delay/periodicity impact: Measured in subframe n, apply in n+10 Gaussian noise (in lognormal) is added to the SINR upon which the link adaptation is based This noise is to model the uncertainty of UE power headroom, flashlight effect, channel estimation error Exact method to be further discussed, e.g. 2-3dB (lognormal) variation for flashlight effect Link adaptation should assume the highest MCS that still meets 10% BLER target (outer loop) - 25% BLER results can also be considered

Introduction Contents of this contribution In this document, with the agreed simulation parameters, we compared the two remaining options for UL SU-MIMO operation: - Option 1: no Layer Shifting & no ACK Bundling (LP0+AB0) - Option 2: Layer Shifting & ACK Bundling (LP1+AB1) Meanwhile, the requested statistics of error events of the two codewords are provided.

Simulation Parameters Carrier frequency 2.0GHz System bandwidth 5MHz Data transmission BW 4 RBs (48 subcarriers) Slot format Normal CP (7 symbols per slot) Channel model (PDP) Typical Urban, 6 paths Fading speed 3, 30, 60, 120km/h Antenna configuration 2x2 Tx Antenna correlation 0.0 Rx Antenna correlation Channel coding Turbo code Modulation QPSK, 16QAM, 64QAM Receiver MMSE-SIC Channel estimation Perfect AMC target BLER 10% at 1st subpacket for both CWs Link measurement/prediction delay 10ms Precoding codebook 2x2 Identity matrix Layer blanking during re-txmn for 2 Ack/Nacks No Interference Variation Modeling for Link Prediction (dB) Gaussian with 2.5dB deviation AGI 0, 6dB

Interference Variation Modeling Parameter Configuration Simulation Scenario D1 (500m ISD) 19 Cell-Sites wrap-around layout Traffic Model Full Buffer #UEs/Cell 10 Max UE Tx Power 23dBm Configured SRS Period Once every 2ms Channel Estimation Loss Modeled Channel Model Typical Urban Receiver LMMSE Overload Indicator (OI) Sent Period 10ms X2 Delay Modeling Exponential with 20ms mean min: 10ms, max: 100ms Power Control Algorithm Adaptive Power Control IoT Target 7.0dB Antenna Config 1x2 Scheduling Algorithm Proportional fair with sub-band scheduling (1 subband = 4RB) Adaptive Power Control: Every 10ms, each cell sends the OI via X2 interface, the serving cell receives the relevant OIs from neighbors and determines the PSD adjustment for each scheduled UE. A UE will change its PSD as it receives its scheduling grant: IF Overloaded NextScheduledPSD = PreviousScheduledPSD – Delta_Dw; ELSE NextScheduledPSD = PreviousScheduledPSD + Delta_Up; where Deleta_Dw and Delta_Up are chosen from {0.4, 0.8}dB adaptively according to the received SINR.

Simulation Results: AGI=0dB, 3km/h Prob(CW2 Terminates at 1st Txmn | CW1 Terminates at 1st Txmn) Achieved BLER at 1st Txmn for each Codeword

Simulation Results: AGI=0dB, 30km/h

Simulation Results: AGI=0dB, 60km/h

Simulation Results: AGI=0dB, 120km/h

Simulation Results: AGI=6dB, 3km/h

Simulation Results: AGI=6dB, 30km/h

Simulation Results: AGI=6dB, 60km/h

Simulation Results: AGI=6dB, 120km/h

Conclusion From previous simulation results, we can have the following observations: layer shifting with 1 ACK option achieves similar performance as no layer shifting with 2 ACKs at low mobility better performance than no layer shifting with 2 ACKs at medium to high mobility As a result we recommend the following: Layer shifting with a single ACK as a single LTE-A UL MIMO operation mode References: [1]. R1-091628, “Link Analyses of SU-MIMO for UL of LTE-A,” Qualcomm Europe. [2]. R1-094222, “Further Link Analyses of SU-MIMO Operation for UL of LTE-A,” Qualcomm Europe.