Summary
IEICE Information and Communication Technology Forum
2015
Session Number:SESSION7
Session:
Number:SESSION7-1
Overloaded Multiple Access for Next Generations of Wireless Communications
Alberto G. Perotti,
pp.-
Publication Date:2015-08-31
Online ISSN:2188-5079
DOI:10.34385/proc.22.SESSION7-1
Summary:
Future wireless networks are expected to have significantly increased downlink (DL) data traffic, either in the form of increased number of users (UEs) connected to a single DL transmitter (for example, the UEs might be sensors), or in the form of multiple, virtually concurrent data streams transmitted to the same UE from a single transmitter (for example, where each stream corresponds to a different application running on the same UE). Both cases can be modelled as an increased number of high-rate DL data streams, which might be difficult or impossible to achieve through an orthogonal multiple access method, i.e. without using resource elements (Res) for simultaneous transmissions to multiple UEs. The simultaneous transmission of multiple signals using common time-frequency-space REs is the basic feature of Over-Loaded multiple access (OLMA) methods. The practical OLMA methods can be designed starting from different scenarios, where each scenario is characterized by a specific optimization criterion or target for selection of transmission parameters, leading to quite different solutions. In one overloading scenario, the target is to increase the number of UEs served per RE, but without increasing transmit power per RE. In this presentation we will discuss three practical schemes of this type that are currently considered in 3GPP Release 13 Study on Enhanced Multiuser Transmissions. In another scenario, the optimization target is the maximization of the aggregate DL spectral efficiency (of one transmitter) by simultaneous transmission to the UEs experiencing similar physical communication channel qualities. The corresponding OLMA methods thus preserve the same data rate, the same transmitted energy per bit of each multiplexed stream, and the same scheduler design as if each of the multiplexed streams would have been transmitted alone on observed time-frequency-space resources. Several OLMA schemes designed using this principle will be discussed in the second part of the talk.