無線寬頻網(wǎng)絡(luò)設(shè)計(jì)規(guī)劃研究報(bào)告-wenkub.com
2025-08-01 01:14 本頁面
【正文】 Downlink Interference (5) If the ratio is higher than 10 dB, the downlink SIR at that cell is OK.(cell A)的干擾就在可接受的范圍內(nèi)了.For the uplink SIR, we find the uplink RSSI at the home AP for a cell A. Now for every other AP using the same channel, we need to calculate interference as follows. Gather all grid cells served by this AP. Calculate the average uplink RSSI from this area to the home AP of cell A. This is the interference from that AP area to cell A. Sum up all this kind of uplink interference RSSI’s from all other AP’s using the same channel as cell A. This is the total uplink interfering signal.關(guān)于uplink A所屬AP的uplink .(cell A)到指定AP的uplink interference (6) Uplink Interference = S RSSI ith area (6) Taking the ratio of the cell A uplink signal and this interfering signal, we get uplink SIR of cell A. If this ratio is higher than 10 dB, cell A is OK.取得了格子A的uplink uplink干擾就在可接受范圍內(nèi)了. Uplink SIR = RSSI cell A 184。WIFI RF SYSTEM DESIGN無線寬頻網(wǎng)絡(luò)設(shè)計(jì)規(guī)劃研究報(bào)告7/2/2005A． IntroductionCoverage, interference, and blocking considerations are the center of the RF system design work. For any point in the service area of the RF system, we must first have enough RSL in both uplink and downlink directions. The required signal is mainly to bat the noise in the environment. In an analog voice system, this RSL provides the system with enough S/N so that the voice quality is acceptable. In a digital system, the S/N renders a low enough BER so that the amount of retransmission is within limit and the system can operate normally. Coverage can be improved by raising the transmitter power or by installing more transmitter sites. But doing so will have impact on the other two design considerations let alone the cost factor.含蓋,干擾,( Downlink )及上行( Uplink )( RSL )應(yīng)該滿足系統(tǒng)中主訊號與噪聲的比值( S/N )..The cochannel interference has similar effect as the noise. It also deteriorates the munications quality and must be controlled. Raising the power of a transmitter can improve SIR and the munication quality but there are limits to the maximum power a transmitter can have. Besides, raising the power of one transmitter can raise the interference at other receivers and adversely impact the performance of the whole system. Consequently, arbitrarily raising transmitter power does not seem to be a viable solution.同頻干擾和噪聲對R/( SIR ),.The cochannel interference es as an unavoidable consequence of channel reuse. The channel can be a frequency channel in an FDMA system, a time slot in a TDMA system, or a code in a CDMA system. The amount of cochannel interference is determined by how the channels are reused spatially. This is the essence of cellular systems. If the channels are used more frequently in an attempt to enhance the system capacity, the cochannel interference tends to increase and the munication quality declines and vice versa. It is the prudent balance of these two conflicting considerations that produce an optimum system. channel .The last consideration is the blocking. The density of sites need
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