Designing a High speed Wireless Data Link Line of Sight Link Budget Analysis Several major…

Designing a High speed Wireless Data Link Line of Sight Link Budget Analysis Several major factors that can impact the performance of a radio system are • Available/permitted output power, • Bandwidth, • Receiver sensitivity, • Antenna gains • Environmental conditions In this case study, the students will be required to calculate the link budget for a LOS Wireless link. Read through the following to understand some of the aspects and elements that need to be considered when calculating a Link Budget. Received Power If the estimated/calculated received power is sufficiently large (relative to receiver sensitivity), the link budget is sufficient for sending data. Received Power (dBm) = Transmitted Power (dBm) + Gains (dB) – Losses (dB) Gains(dB)=Transmit Antenna gain+ Receiver Antenna Gain Receiver sensitivity is the lowest power level at which the receiver can detect an RF signal and demodulate data. Link Margin/Fade Margin The amount by which the received power exceeds receiver sensitivity is called the link margin/fade margin. In wireless systems, multipath propagation results in multiple copies of a signal to arrive at different signal phases at the receiver. If these signals add up destructively, the resulting signal power can be lower by a factor of 100 or 1000 (20 or 30 dB). The signal level relative to the noise declines making signal detection at the receiver more difficult. It is therefore highly recommended to keep a link margin of 30 dB when designing a wireless system.