Example 9: Adjacent Channel Power Measurement - Agilent Technologies 8560E User Manual

Making Measurements

Example 9: Adjacent Channel Power Measurement

Example 9: Adjacent Channel Power
Measurement
What Is Adjacent Channel Power (ACP)?
Adjacent channel power measures the modulation that leaks from the
intended channel of a communication device, such as a cellular radio,
into an adjacent channel. That leakage may degrade communication
among users of the adjacent channels. Therefore, regulatory bodies
specify the amount of power that is allowed to leak into the adjacent
channels. (Regulations can also specify the leakage into the first and
second alternate channels.)
Adjacent channel power may be measured directly for continuously
modulated carriers, as in the many analog FM systems. There are
many complex standards for measuring ACP in systems that use burst
carriers like TDMA (time-division multiple access) cordless phones and
cellular systems. These signals can also be measured with a spectrum
analyzer.
Spectrum Analyzer Functions Used
The ACP examples are applicable to spectrum analyzers with firmware
revisions >930809. Earlier firmware revisions do include a limited
amount of ACP functionality. Its operation is similar to the
function which is documented in "Stepping
ACP AUTO MEASURE
Through a Basic ACP Measurement".
Two examples of adjacent channel power measurements are shown, a
basic measurement using the analog measurement method and a
measurement of a burst signal using the two-bandwidth method.
Calculations are made for measurements such as the ACP leakage ratio
and the total transmitted power. The channel spacing and channel
bandwidth with which the measurement was made are also displayed.
The following topics are covered in this example:
• Stepping Through a Basic ACP Measurement
• ACP Analog Method Information
• Stepping Through a Burst Signal ACP Measurement
• PDC Measurements of Mobiles According to the RCR-27B Standard
• PHS Measurements of Mobiles According to the RCR-28 Standard
• NADC Measurements of Mobiles According to the IS-54 Standard
108 Chapter 2