Why is receiver sensitivity a required specification in a link budget?

Why is receiver sensitivity a required specification in a link budget?

• A. It sets the minimum signal level for acceptable BER.
• B. It sets the transmitter power.
• C. It determines the antenna size.
• D. It is optional.

Answer: (A)

Receiver sensitivity is the minimum input power the receiver needs at its input to achieve the required error performance (BER) at the chosen data rate. In a link budget you balance transmitter power and gains against path losses and noise, and you compare the resulting received power to this sensitivity. If the received signal is at or above the sensitivity, the target BER can be met; if it’s below, no amount of tweaking elsewhere will rescue the link because the receiver can’t decode reliably at that level. So sensitivity sets the threshold the link must exceed to work properly, making it a necessary specification. It doesn’t set transmitter power—those are separate parameters you adjust to meet the threshold. It isn’t a direct determinant of antenna size, though a larger antenna can improve the received power and help reach the sensitivity requirement. And it isn’t optional in a complete link budget; knowing the receiver’s sensitivity is essential to verify that the link will meet the performance goals.

Receiver sensitivity is the minimum input power the receiver needs at its input to achieve the required error performance (BER) at the chosen data rate. In a link budget you balance transmitter power and gains against path losses and noise, and you compare the resulting received power to this sensitivity. If the received signal is at or above the sensitivity, the target BER can be met; if it’s below, no amount of tweaking elsewhere will rescue the link because the receiver can’t decode reliably at that level. So sensitivity sets the threshold the link must exceed to work properly, making it a necessary specification.

It doesn’t set transmitter power—those are separate parameters you adjust to meet the threshold. It isn’t a direct determinant of antenna size, though a larger antenna can improve the received power and help reach the sensitivity requirement. And it isn’t optional in a complete link budget; knowing the receiver’s sensitivity is essential to verify that the link will meet the performance goals.