Using the following data for GSM 1800, Develop downlink and uplink budget and determine the cell radius

- Base Station Transmit Power (Pb) = 36 dBm = 4W

- Mobile Station Transmit Power (Pm) = 24 dbm

- Base Station Noise Figure = 5 dB

- Mobile Station (hand held unit) Noise Figure = 8 dB

- Base Station Transmit and receive antenna gain (GA) = 18 dBi

- Mobile Antenna gain = 0 dBi

- Required signal to noise ratio (SNR) = 12 dB

- Transmit antenna cable, connector loss (Lc) = 5 dB

- BS Receiver antenna cable, connector loss (Lc) = 2 dB

- Orientation/Body loss of mobile = 3 dB

- Shadow Fading = 10.2 dB

- Thermal Noise density = -174 dBm/Hz

- Antenna Diversity gain at BS= 5 dB

Mumbai University > Electronics and Telecommunication > Sem8 > Wireless Networks

Marks: 10M

Year: May 2013

Mobile station noise floor:

N=-174+10log(200,000)+Noise figure=-174+53+8=-113dBm

$S_\text{min}=N+(S/N)_\text{reqd}$ = -113+12=-101dBm

Mean signal required at mobile station:

$S_\text{mean}=S_\text{min}$+shadow fading +(orient) /(body)=-101+10.2+3=-87.8dBm.

Lp=Pt-Lc+GA-$S_\text{mean}$=36-5+18-(-87.8)=136.8dB

Base station noise floor:

N==174+10log(200,000)+8=-116dBm.

$S-\text{min}$ for acceptable quality with diversity:

$S_\text{min}=N+(S/N)_\text{reqd}$-diversity=-116+12-5=-109dBm

Mean signal required at base station:

$S_\text{mean}=S_\text{min}$+ shadow fading +(orient)/(body)=-109+10.2+3=-95.8dBm

We use uplink path loss and Hata model to calculate cell radius as:

Lp=133.2+33.8logR; where R is the cell radius in kilometers.

$\therefore R=10^{(135.8-132.2)/33.8}-1.2km$