Abstract:
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This paper deals with the interference control in the uplink
(UL) of Long Term Evolution (LTE) systems. Although the multiple
access technique allows an almost null intra-cell interference, the system
is still sensitive to the inter-cell component caused by neighbouring
cells. The UL power control proposed by the 3GPP is a means to reduce
this interference. In this sense, user equipments (UE) establish an
operation point (open loop power control or OLPC) to compensate the
mean path loss and its slow variations. Additionally, this may be fine
tuned by specific commands (closed loop). The current paper focuses
on the performance of OLPC when deployed in realistic scenarios where
heterogeneity is a key feature, both in the deployment of sites and in the
concentration of users. The investigation is done in a comparative way,
against a classic synthetic and regular scenario. Results indicate that the
performance of the OLPC differs from the theoretical environment, due
to the difference in the scenario nature. The summation of indoor coverage
and guided path-loss results the urban scenario OLPC optimal point
to lie in between two limits, one established by the reduced transmitted
power fixed by the OLPC and the other by the interferences. |