What's Link Budget in wireless communication

Link budget is a concept used in wireless communication systems to calculate a signal's total gain and loss as it travels from the transmitter to the receiver. The link budget ensures sufficient signal strength to maintain a reliable communication link between the two points.

The link budget includes several factors, including:

1. Transmitter Power: The transmitter's power, is measured in watts or decibels (dB).

2. Antenna Gain: The gain of the transmitter and receiver antennas, which measures how well the antennas can convert the input power into a radiated signal and vice versa.

3. Propagation Loss: The loss of signal strength as it travels through the air, which is affected by factors such as distance, terrain, and obstacles.

4. Receiver Sensitivity: The minimum power level required for the receiver to detect and correctly decode the signal.

5. System Margin: A safety factor that accounts for any additional losses or uncertainties in the system, such as temperature variations, equipment degradation, or interference.

The link budget is calculated by adding up the gains and losses at each stage of the signal path, starting from the transmitter and ending at the receiver. The result measures the signal strength at the receiver, which is compared to the minimum required signal strength (receiver sensitivity) to determine if the communication link is viable.

A link budget is an essential tool in wireless communication system design and optimization, as it allows engineers to predict the system's performance under different conditions and make adjustments to improve the reliability and efficiency of the communication link.