On the Impact of Inter-Cell Interference in LTE

[ahmedtaha]

Abstract

—While intercell interference coordination (ICIC) for
the downlink of multi-cell systems in general and orthogonal
frequency division multiple access (OFDMA) networks in particular
has been extensively studied, the uplink has received less
attention. For the uplink, the impact of ICIC on the overall
system throughput (“the ICIC gain”) must be analyzed in a
system model that captures specific constraints such as power
limitation and the behavior of other radio resource management
functions including scheduling, fast packet retransmissions by
means of hybrid automatic repeat requests (HARQ), power
control and adaptive modulation and code rate selection. In
this paper we investigate the ICIC gain for the uplink of the
3GPP Long Term Evolution (LTE) system and find that this gain
much depends on the employed traffic model. Specifically, for
non greedy (sometimes termed “non full buffer”) traffic sources,
HARQ and link adaptation are able to compensate the effect of
intercell collisions and therefore the real ICIC gains are typically
smaller than those reported based on full buffer models assuming
greedy traffic. We expect that our findings provide useful insights

for the system design of ICIC schemes.