TY - JOUR
T1 - Reliability analysis of Uplink Grant-Free transmission over Shared Resources
AU - Berardinelli, Gilberto
AU - Mahmood, Nurul Huda
AU - Abreu, Renato Barbosa
AU - Jacobsen, Thomas
AU - Pedersen, Klaus I.
AU - Kovacs, Istvan Z.
AU - Mogensen, Preben Elgaard
PY - 2018
Y1 - 2018
N2 - Uplink grant-free schemes have the promise of reducing the latency of a user-equipment-initiated transmission by avoiding the handshaking procedure for acquiring a dedicated scheduling grant. However, the possibility of successfully delivering a payload within a latency constraint may be severely compromised in case of grant-free operations over shared radio resources. In this paper, we study the performance of two different uplink grant-free schemes over shared resources recently discussed within the fifth generation new radio standardization, namely, a solution based on a stop-and-wait (SAW) protocol and a blind retransmission approach. Performance is evaluated assuming Rayleigh fading channels with a maximum ratio combining (MRC) multi-antenna receiver. Analytical results show the benefits of grant-free transmission with respect to the traditional grant-based approach for a tight latency constraint. A high-order receive diversity is beneficial to leverage the MRC gain and enables the possibility of achieving the 10
-5 outage probability target set for ultra-reliable low-latency communication services. The blind retransmission approach is significantly penalized by identification and signaling errors, while a SAW solution with potentially scheduled retransmissions out of the shared bandwidth leads to the lowest outage probability, at least for frequent packet arrivals.
AB - Uplink grant-free schemes have the promise of reducing the latency of a user-equipment-initiated transmission by avoiding the handshaking procedure for acquiring a dedicated scheduling grant. However, the possibility of successfully delivering a payload within a latency constraint may be severely compromised in case of grant-free operations over shared radio resources. In this paper, we study the performance of two different uplink grant-free schemes over shared resources recently discussed within the fifth generation new radio standardization, namely, a solution based on a stop-and-wait (SAW) protocol and a blind retransmission approach. Performance is evaluated assuming Rayleigh fading channels with a maximum ratio combining (MRC) multi-antenna receiver. Analytical results show the benefits of grant-free transmission with respect to the traditional grant-based approach for a tight latency constraint. A high-order receive diversity is beneficial to leverage the MRC gain and enables the possibility of achieving the 10
-5 outage probability target set for ultra-reliable low-latency communication services. The blind retransmission approach is significantly penalized by identification and signaling errors, while a SAW solution with potentially scheduled retransmissions out of the shared bandwidth leads to the lowest outage probability, at least for frequent packet arrivals.
KW - Multiple access
KW - URLLC
KW - grant-free transmission
UR - http://www.scopus.com/inward/record.url?scp=85045768711&partnerID=8YFLogxK
U2 - 10.1109/ACCESS.2018.2827567
DO - 10.1109/ACCESS.2018.2827567
M3 - Journal article
SN - 2169-3536
VL - 6
SP - 23602
EP - 23611
JO - IEEE Access
JF - IEEE Access
ER -