Training Sequence Length Optimization for a Turbo-Detector Using Decision-Directed Channel Estimation

<table>MAP equalizer BER performance versus <svg height="14.7125" id="M122" style="vertical-align:-3.22281pt" version="1.1" viewbox="0 0 42.625 14.7125" width="42.625" xmlns="http://www.w3.org/2000/svg">
<g transform="matrix(1.25,0,0,-1.25,0,14.7125)">
<g transform="translate(72,-60.23)">
<text transform="matrix(1,0,0,-1,-71.95,63.5)">
<tspan style="font-size: 12.50px; " x="0" y="0">S</tspan>
<tspan style="font-size: 12.50px; " x="6.9516678" y="0">N</tspan>
<tspan style="font-size: 12.50px; " x="15.978834" y="0">R</tspan>
</text>
<text transform="matrix(1,0,0,-1,-47.63,60.37)">
<tspan style="font-size: 8.75px; " x="0" y="0">e</tspan>
<tspan style="font-size: 8.75px; " x="3.8858881" y="0">ﬀ</tspan>
</text>
</g>
</g>
</svg> for different values of the length of the
training sequence after two and three iterations of the iterative receiver for <i>Channel</i> 4, <svg height="11.1" id="M123" style="vertical-align:-0.17555pt" version="1.1" viewbox="0 0 51.549999 11.1" width="51.549999" xmlns="http://www.w3.org/2000/svg">
<g transform="matrix(1.25,0,0,-1.25,0,11.1)">
<g transform="translate(72,-63.12)">
<text transform="matrix(1,0,0,-1,-71.95,63.35)">
<tspan style="font-size: 12.50px; " x="0" y="0">𝑇</tspan>
<tspan style="font-size: 12.50px; " x="10.339981" y="0">=</tspan>
<tspan style="font-size: 12.50px; " x="22.380369" y="0">5</tspan>
<tspan style="font-size: 12.50px; " x="28.63187" y="0">1</tspan>
<tspan style="font-size: 12.50px; " x="34.883369" y="0">2</tspan>
</text>
</g>
</g>
</svg> and <svg height="10.9125" id="M124" style="vertical-align:-0.17555pt" version="1.1" viewbox="0 0 59.412498 10.9125" width="59.412498" xmlns="http://www.w3.org/2000/svg">
<g transform="matrix(1.25,0,0,-1.25,0,10.9125)">
<g transform="translate(72,-63.27)">
<text transform="matrix(1,0,0,-1,-71.95,63.5)">
<tspan style="font-size: 12.50px; " x="0" y="0">𝛿</tspan>
<tspan style="font-size: 12.50px; " x="6.2765059" y="0">𝑇</tspan>
<tspan style="font-size: 12.50px; " x="16.62899" y="0">=</tspan>
<tspan style="font-size: 12.50px; " x="28.669378" y="0">1</tspan>
<tspan style="font-size: 12.50px; " x="34.920879" y="0">0</tspan>
<tspan style="font-size: 12.50px; " x="41.172379" y="0">0</tspan>
</text>
</g>
</g>
</svg>.</table>

Journal of Electrical and Computer Engineering

fig5

Figure 5

Figure 5: Training Sequence Length Optimization for a Turbo-Detector Using Decision-Directed Channel Estimation 