Technical data

Chapter 8 253
CDMA Over Air
Metrics Provided by CDMA Over Air Measurements
CDMA Over Air
Below is a table showing various delays vs. distance.
Estimated Rho
Estimated Rho is the measure of the modulation quality for a CDMA transmitter.
This measurement is analogous to measuring FM accuracy and distortion in an
AMPS network or EVM in a TDMA system. A Rho value of 1.0 is perfect,
indicating that all of the power is being transmitted correctly.
Carrier Feedthrough
Carrier Feedthrough is a result of the RF carrier signal feeding through the I/Q
modulator and appearing at the transmitter port. Carrier Feedthrough is a common
cause of bad Rho measurements.
Noise Floor
Noise Floor is the average power of all the inactive channels.
Channel Power
Channel Power is the total power within a defined bandwidth. For CDMA the
channel bandwidth is defined to be 1.25 MHz. Channel Power measures the power
the base station is transmitting across the entire 1.25 MHz CDMA channel.
Pilot Power
Pilot Power is the total power in the Pilot code channel, expressed in dBm. The
transmit power of the Pilot Channel signal for a given base station is constant.
Pilot Ec/Io
The Pilot Ec/Io is the ratio of the pilot power to all the other power in the channel,
expressed in dB. Since Ec and Io are measured individually, the system can detect
Distance Delay
161 meters (0.1 mile) 0.56 µs
402 meters (0.25 mile) 1.36 µs
805 meters (0.5 mile) 2.72 µs
1609 meters (1 mile) 5.28 µs
8047 meters (5 miles) 26.4 µs