UMTS / CDMA Sector Parameters
All CDMA sector parameters are initially configured by default when selecting the study service (technology), with values appropriate or typical of the simulation type to be performed. It is recommended, however, to be checked and specified by the user to adapt their simulation to the equipment realit that is intended to simulate.
CDMA parameters are only present when a third- and fourth-generation radio service in the "Mobile Service" group is used.
Depending on the path type to simulate, the Downlink or Uplink parameters specified in the CDMA parameters will be used in the calculation.
The following parameters are not present in all services, since some of them are meaningless:
•Binary Rate (Kbps). Source rate or rate perceived by the user, not including channel coding or other processes that modify it.
•Power range (dB). CDMA systems use fast power control to compensate for multipath fading. The "effective" maximum value of averaged power with respect to rapid variations is obtained as the peak power minus a power range. Typically between 0 and 8 dB.
•Pilot channel power. Power of the sector pilot signal.
•Control channel power. Power of the control channel.
•Required EB/N0 ratio (dB). In CDMA systems the EB/N0 ratio value required to declare a point as covered, rather than receive threshold, is specified and its value represents the level of signal needed above interfering signals needed to establish the communication.
•Charge factor (%). Relation between users number allowed per cell and the theoretical maximum corresponding to asymptotic capacity (maximum users number that the cell can support if an arbitrarily large noise increase is allowed). This parameter is between 0 (unloaded cell, maximum coverage distance) and 100% (fully charged cell, the coverage area has been reduced to a single point). In practice, it is usually limited to values between 50% and 75%.
•Noise factor (dB). Noise factor of the sector.
•SHO gain by shadow fading (dB). When evaluating the cell coverage can be assumed that users located on the cell's edge are in a position to handover continuously (soft handover) with one or more neighboring cells, so they are received simultaneously at several bases. As a result, there is improvement due to reception diversity. One effect of this diversity is that the margin necessary to take into account the shadow fading is less than the one that would exist with a single base. There is thus a gain term, which must be subtracted from the log-normal margin calculated as usual. If in this margin calculation has been taken into account this effect is not necessary to apply any corrections.
•SHO multipath gain (dB). Another effect of the reception diversity associated with the handover is a decrease in the required EB/N0 ratio. As in the previous case, if the EB/N0 value specified already takes into account the gain per handover it is not necessary to apply any correction. Typical values are between 0 and 2 dB.
•Receiver antenna diversity gain(dB). In case of using more than one antenna in the sector reception.
•Sensitivity (dBm). Power needed at reception, is calculated from previous parameters when clicking the link "Calculate sensitivity".