Generalized Superposition Modulation and Iterative Demodulation: A Capacity Investigation

<table>Signaling arrangement for the <svg height="10.7375" id="M103" style="vertical-align:-0.13794pt" version="1.1" viewbox="0 0 8.6000004 10.7375" width="8.6000004" xmlns="http://www.w3.org/2000/svg">
<g transform="matrix(1.25,0,0,-1.25,0,10.7375)">
<g transform="translate(72,-63.41)">
<text transform="matrix(1,0,0,-1,-71.95,63.6)">
<tspan style="font-size: 12.50px; " x="0" y="0">𝑘</tspan>
</text>
</g>
</g>
</svg>th data stream. Symbols aggregating on the same channel node may use orthogonal signal waveforms. The actual received signal vectors <svg height="11.2375" id="M104" style="vertical-align:-3.13504pt" version="1.1" viewbox="0 0 13.025 11.2375" width="13.025" xmlns="http://www.w3.org/2000/svg">
<g transform="matrix(1.25,0,0,-1.25,0,11.2375)">
<g transform="translate(72,-63.01)">
<text transform="matrix(1,0,0,-1,-71.95,66.19)">
<tspan style="font-size: 12.50px; " x="0" y="0">𝐲</tspan>
</text>
<text transform="matrix(1,0,0,-1,-65.7,63.06)">
<tspan style="font-size: 8.75px; " x="0" y="0">𝑟</tspan>
</text>
</g>
</g>
</svg> are the superposition of <svg height="10.325" id="M105" style="vertical-align:-0.0pt" version="1.1" viewbox="0 0 13.2875 10.325" width="13.2875" xmlns="http://www.w3.org/2000/svg">
<g transform="matrix(1.25,0,0,-1.25,0,10.325)">
<g transform="translate(72,-63.74)">
<text transform="matrix(1,0,0,-1,-71.95,63.79)">
<tspan style="font-size: 12.50px; " x="0" y="0">𝐾</tspan>
</text>
</g>
</g>
</svg> such data streams, causing the channel nodes to have large message degrees.</table>

Journal of Electrical and Computer Engineering

fig3

Figure 3

Figure 3: Generalized Superposition Modulation and Iterative Demodulation: A Capacity Investigation 