EVDO Signal Analyzer 3-9 EVDO Measurement Descriptions
3GPP2 MG PN: 10580-00235 Rev. D 3-17
Rho
Rho is a number between 0 and 1. A good signal should have a Rho that is close to 1. When
connected to a good EVDO source, all Rhos should be 0.97 or above, and should decrease when
the channel power is too weak. When noise or distortion is present, for example in an
over-the-air measurement, Rhos can drop dramatically.
Rho Pilot
Rho Pilot is an indicator of the quality of the Pilot Channel.
Rho Data
Rho Data is an indicator of the quality of the Data Channel.
Rho MAC
Rho MAC is an indicator of the quality of the MAC Channel.
Rho Overall 1 and 2
Rho Overall 1 and 2 are both indicators of the overall quality of the EVDO signal during an
active slot. They differ from each other in the sense that Rho Overall 1 measures from the
beginning to the end of a half slot, while Rho Overall 2 measures from the middle of one half
slot to the middle of another half slot. In general, they should have similar values.
Carrier Feedthrough
Carrier Feedthrough measures the amount of unmodulated signal that is leaking through the
transmitter.
CDP Data
The Data Channel in EVDO consists of 16 “I” sub channels and 16 “Q” sub channels. Each of
these channels should have a power of approximately -15.05 dB relative to the total Data
Channel power. When connected to a good signal source, the Data Code Min is usually larger
than -15.5 dB, and the Data Code Max is usually less than -14.6 dB. The smaller the
difference between these two values, the better the signal quality.
CDP MAC
MAC channels are Walsh despread into 64 sub-channels (physical layer Subtype 0 or 1) or
128 sub-channels (physical layer Subtype 2). See the menu description for CDP MAC for color
code details.
Pilot Scan
The strongest 9 PNs that are received are displayed. The length of the bar represents the
absolute or relative power of the signal in dBm or dB. The strongest PN or the user-selected
PN is color coded blue, those colored red are probably real pilots, and the remaining, which
are color coded gray, are probably noise.
Multipath
The length of the bar represents the relative power in the signal path in dB. Ec/Io and Tau
are displayed below each bar. The strongest signal is color coded blue. The remaining signals
are color coded red, or they are color coded gray if they are due to system noise.
Note This graph is not meaningful if the PN search is set to No Trigger.
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