CDMA无线参数
MeasurementDefinition
GPS timing offset The timing offset is defined as the difference in time between when a pilot signal is actually received and when it should have been transmitted, as defined by GPS timing. Used to detect base station timing offset problems. Timing offset problems can lead to "island" cells, which have difficulties handing calls off to neighboring cells.
EcThe total power received from an individual base station on its pilot channel.
IoIo is a measure of the total power in the 1.2288 MHz band at the time of the Ec/Io measurements. Io is measured separately and simultaneously with Ec/Io. If either the All Pilots or Top N measurements are present, Io is measured across the entire short code period (26.7 ms) that the Ec/Io data is collected. If only a subset of the short code period is measured with a Zoomed measurement or User List as the only measurements present, the Io returned will reflect the total power averaged only over the subset of the short code period used to collect the Ec/Io data.
Ec/IoThe fractional power of the pilot channel of the individual base stations divided by the total power. Since Ec and Io are measured individually, the system can detect poor signal quality and tell you if it is caused by low Ec or high Io. This helps you quickly resolve coverage versus interference issues.
A high value of Ec/Io means there is less interference from other base stations and noise and is an indicator of base station performance. When Ec/Io is mapped it can be used to determine areas that have low coverage.
Carrier errorDisplays the difference between the measured carrier frequency and the user-specified carrier frequency. Carrier error can be due to base station carrier error and also, if moving, Doppler shift.
All pilots trace
(Ec/Io)Measures Ec/Io associated with all pilots.
Io for all pilotsMeasures Io associated with all pilots.
Pilot top N (Ec/Io)Displays Ec/Io for the top N pilot channels received, where N is a user definable integer from 1 to 20. The data is displayed in a bar chart.
Io for top NDisplays Io for the top N pilot channels received, where N is a user definable integer from 1 to 20.
Pilot list (Ec/Io)Displays Ec/Io for a pilot list.
Io for pilot listDisplays Io for a pilot list.
Pilot timing delayA timing delay can be displayed on the top of each bar graph display for Top N and User List measurements. The timing delay is defined as the difference between the time when a pilot signal is received and the time when it should have been transmitted, as determined by GPS timing. Timing delays can be due to propagation delay and base station timing problems.
Carrier frequency stateAssesses the success of a carrier recovery algorithm invoked at each measurement update to track a drifting CDMA carrier.
Drifting indicates the unit is uncertain of its time synchronization and movement results are suspect.
Valid indicates the algorithm successfully received the carrier.
Free Running indicates that recovery was not successful so that last valid carrier recovery is being used.
CDMA time stampA modulo 1024 second time stamp recorded by the CDMA measurement before sending results back to the PC. The CDMA time stamp cannot be precisely synchronized with the PC time stamp of the measurement but is accurate enough to determine delta times between measurement updates.
Zoomed pilot trace
(Ec/Io)Displays the Ec/Io for a user-specified center/span or start/stop chip or PN offset values.
Io zoomed-in pilotsDisplays Io for zoomed in measurement.