An Investigation of the Impact of Signal Strength on Wi-Fi Link ...
An Investigation of the Impact of Signal Strength on Wi-Fi Link ...
An Investigation of the Impact of Signal Strength on Wi-Fi Link ...
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modulati<strong>on</strong> in [37]. According to simulati<strong>on</strong> results, <str<strong>on</strong>g>the</str<strong>on</strong>g> DOC-CCK almost eliminates<br />
co-channel interference when two BSSs are located in <str<strong>on</strong>g>the</str<strong>on</strong>g> same area.<br />
In c<strong>on</strong>clusi<strong>on</strong>, interference <str<strong>on</strong>g>of</str<strong>on</strong>g> radio frequency is a usual problem and has significant<br />
impacts <strong>on</strong> data throughput in wireless communicati<strong>on</strong>. The studies give us an insight<br />
into understanding <str<strong>on</strong>g>the</str<strong>on</strong>g> impact <str<strong>on</strong>g>of</str<strong>on</strong>g> interference <strong>on</strong> WLAN performance and mitigating <str<strong>on</strong>g>the</str<strong>on</strong>g><br />
effects <str<strong>on</strong>g>of</str<strong>on</strong>g> interference. The studies also have pr<str<strong>on</strong>g>of</str<strong>on</strong>g>ound implicati<strong>on</strong>s for propagati<strong>on</strong><br />
measurement.<br />
Multiple-Path Propagati<strong>on</strong><br />
Reflecti<strong>on</strong> or diffracti<strong>on</strong> leads to multiple-path propagati<strong>on</strong>. Multiple-path propagati<strong>on</strong><br />
is a comm<strong>on</strong> event in <str<strong>on</strong>g>the</str<strong>on</strong>g> indoor envir<strong>on</strong>ment. The radio signal would reflect from<br />
objects during transmissi<strong>on</strong> (e.g. wall, ceiling and <str<strong>on</strong>g>of</str<strong>on</strong>g>fice partiti<strong>on</strong>). The effect <str<strong>on</strong>g>of</str<strong>on</strong>g><br />
multiple-path propagati<strong>on</strong> causes <str<strong>on</strong>g>the</str<strong>on</strong>g> fading <str<strong>on</strong>g>of</str<strong>on</strong>g> radio signal, so that receiver would not<br />
get sufficient signal power [36]. Moreover, <str<strong>on</strong>g>the</str<strong>on</strong>g> reflected signals will arrive later than<br />
direct signal. The period used to identify duplicate signals is referred to “delay spread”.<br />
In general, <str<strong>on</strong>g>the</str<strong>on</strong>g> large delay spread number has better performance, because stati<strong>on</strong>s and<br />
APs have enough time to identify radio signals [38].<br />
Attenuati<strong>on</strong><br />
When data transmissi<strong>on</strong> occurs between two wireless nodes, <str<strong>on</strong>g>the</str<strong>on</strong>g> signal power is<br />
dropping and getting weak. It is called attenuati<strong>on</strong> [36]. Many factors could result in<br />
attenuati<strong>on</strong>, for example, distance, obstructi<strong>on</strong>, and multiple-path effect. Due to<br />
attenuati<strong>on</strong>, received devices would not have sufficient signal strength. The<br />
performance would degrade significantly. Fur<str<strong>on</strong>g>the</str<strong>on</strong>g>rmore, metal door and structural<br />
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