Uplink Nonorthogonal Multiple Access Technologies Toward 5G: A Survey

<table class="figure-group"><tr class="fig-image" id="a"><td><object data="https://static.hindawi.com/articles/wcmc/volume-2018/6187580/figures/6187580.fig.0034a.svgz" name="6187580.fig.0034a" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(a) </b>Grant-free model</td></tr><tr class="fig-image" id="b"><td><object data="https://static.hindawi.com/articles/wcmc/volume-2018/6187580/figures/6187580.fig.0034b.svgz" name="6187580.fig.0034b" type="image/svg+xml"></object></td></tr><tr class="fig-caption"><td><b>(b) </b>RAC model</td></tr></table>

<div>Illustrations of grant-free transmission and RAC models. <svg height="11.5695pt" id="M37" style="vertical-align:-3.18152pt" version="1.1" viewbox="-0.0498162 -8.38798 16.6725 11.5695" width="16.6725pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M861 0V28C774 35 771 41 768 147L759 509C756 612 762 614 851 622V650H681L449 149L221 650H57V622C148 613 153 609 144 479L130 271C123 166 117 123 111 88C104 46 85 34 26 28V0H259V28C192 35 169 42 167 90C166 130 166 173 170 256L185 541H187L411 7H431L675 555H679L683 147C683 41 680 35 598 28V0H861Z" id="g121-75"></path></g><g transform="matrix(.0091,0,0,-0.0091,11.583,3.132)"><path d="M389 0V32C297 38 291 46 291 118V635C234 613 175 595 109 583V556L161 554C203 552 207 547 207 497V118C207 46 201 38 110 32V0H389Z" id="g50-50"></path></g></svg> and <svg height="11.5695pt" id="M38" style="vertical-align:-3.18152pt" version="1.1" viewbox="-0.0498162 -8.38798 16.6725 11.5695" width="16.6725pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M861 0V28C774 35 771 41 768 147L759 509C756 612 762 614 851 622V650H681L449 149L221 650H57V622C148 613 153 609 144 479L130 271C123 166 117 123 111 88C104 46 85 34 26 28V0H259V28C192 35 169 42 167 90C166 130 166 173 170 256L185 541H187L411 7H431L675 555H679L683 147C683 41 680 35 598 28V0H861Z" id="g121-75"></path></g><g transform="matrix(.0091,0,0,-0.0091,11.583,3.132)"><path d="M414 144C384 79 371 75 317 75H135L276 221C367 316 408 376 408 465C408 570 327 635 237 635C179 635 131 609 100 575L42 494L67 471C94 510 138 565 205 565C277 565 321 517 321 435C321 348 258 270 195 195C146 137 88 81 33 26V0H411C423 44 433 88 446 135L414 144Z" id="g50-51"></path></g></svg> are the messages to be transmitted.</div>

Wireless Communications and Mobile Computing

fig34

Figure 34

Figure 34: Uplink Nonorthogonal Multiple Access Technologies Toward 5G: A Survey 