A radio link budget is a calculation used to predict the performance of a radio communication link. It takes into account various parameters such as the transmitter power, receiver sensitivity, antenna gains, path loss, and any additional losses that may occur in the system. The budget is used to ensure that the link will meet the required performance specifications, such as signal-to-noise ratio, bit error rate, and coverage area.
The link budget calculation starts with the transmitter power, and then subtracts the losses that occur in the system, such as cable loss, connector loss, filter loss, and so on. Then the signal is received by the antenna, and the antenna gain is added. The signal then passes through the atmosphere and the terrain, and the path loss is subtracted. Finally, the signal reaches the receiver and the receiver sensitivity is subtracted.
The final result of the link budget calculation is the signal-to-noise ratio (SNR) at the receiver. The SNR is a measure of the quality of the received signal, and it is used to determine if the link will meet the required performance specifications. If the SNR is not sufficient, adjustments can be made to the system, such as increasing the transmitter power or using a more sensitive receiver.
The link budget calculation is essential for the design and installation of radio systems, in particular for long-range wireless communication systems such as cellular networks, satellite communication systems, microwave links, etc. It is also important for troubleshooting existing systems to identify and solve problems.