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CDMA System configuration dialog window

OBS: the CDMA configuration settings will change as a part of implementing a combined CDMA/OFDMA simulation engine in SEAMCAT 3.2. This information page will be updated once the final configuration and interface of new system will be fixed.

This dialog window is used to define the necessary parameters for modeling of CDMA systems. These parameters have been divided into several related groups - each called by a separate sub-sheet tab.

General

This tab contains a range of general CDMA system parameters as well as some parameters that depend on the modeled direction of CDMA link (uplink vs. downlink). The choice of the link direction is in itself considered to be a general system parameter.

General CDMA System parameters
Name	Description
CDMA Link component	The type of CDMA System. There are considerable differences between modeling of uplink and a downlink in CDMA system. Please consult the page on CDMA algorithms for a more detailed explanation of differences.
Receiver Noise Figure	Equipment-specific noise figure of receiver, specified in dB
Handover margin	Specifies the maximum difference, in dB, between the links in users active list. The actual active-list selection is based on pathloss calculations.
Call drop threshold	Used by power control to determine if a user should be dropped when not meeting exact target requirement, specified in dB
Voice bit rate	Specified in kbps
Reference bandwith	Specified in MHz
Voice activity factor	Decimal in the range 0 - 1 used to specify the percentage of voice active users in system. I.e. a value of 0.5 means that half of all users in system will be voice active at each given time instance (SEAMCAT snapshot). This figure will have large impact on system capacity as only voice active users are considered by CDMA power control
Minimum Coupling Loss	The minimum path loss, specified in dB
Link Level Data	Drop-down selection of Link level data look-up functions from Library. It is user's responsibility to choose an appropriate set of data. General workspace consistency check will check for Link direction and check if frequency difference between operating frequency and the nominal frequency of Link level data set is within 100 MHz

Positioning

The parameters used to configure the geographical configuration and spatial parameters of the modeled CDMA system.

Geographic configuration and spatial parameters of CDMA system
Name	Description
Type of cells in PC cluster	Selection between Omni driectional and Tri-Sector antennas. SEAMCAT uses so called "non-cloverleaf" Tri-Sector cell layout.
Cell Radius	Specified in kilometers, this parameter is used to determine inte-rcell distance given as: radius * sqrt(3)
Base Station antenna height	Distribution used to determine height of BS. Note that the assumed antenna height definition (above ground, above local clutter, effective antenna height) should correspond to the selected propagation model
Base Station antenna	Allows to define the gain of antenna and radiation pattern for directional antenna
Mobile Station Antenna Height	Height of user terminal in meters. Note that the assumed antenna height definition (above ground, above local clutter, effective antenna height) should correspond to the selected propagation model
Mobile Station Antenna Gain	Specified in dB
Mobile Station Mobility	Distribution used to specify simulated speed of users. Note that theese speeds have to conform to the speed options in the selected Link Level Data. For simplicity SEAMCAT assumes four different speeds, assigned to mobile users with uniform probability: 0 km/h - No movement, 3 km/h - Walking, 30 km/h - Urban driving, 100 km/h - Highway driving

Initial Capacity

This tab contains settings for the choice of capacity (loading) of the modeled CDMA, i.e. how many mobiles per cell should be generated in the system.

If the option Simulate non-interfered capacity is checked, then the system will automatically simulate the 'optimal' number of the mobiles for given system configuration specified earlier in the scenario (type of system, bandwidth, cell sizes, etc). The optimum finding algorithm is developed to establish the loading that would correspond to approx. 80% of maximum system capacity. If this option is unchecked, then the user is free to set a constant user-defined average number of mobile users per cell.

Tip: The simulation of non-interferred capacity is a lengthy process. Therefore if the user runs multiple simulations with the same CDMA system (e.g. victim CDMA system unchanged and only interfering system is varied), then it would be sufficient to do the finding of non-interferred capacity in the first run. Then, having noted the result of non-interferred capacity finding exercise (may be seen by consulting the CDMA system view screen available after completion of simulations), in the following runs the user may just set the obtained value as the constant user-defined value (i.e. option unchecked). Note: This assumes that user does not make any changes to the internal settings of the given CDMA system, that would otherwise have impact on loading capacity of the system.

Propagation Model

This tab contains settings for the choice of propagation model to be applied when evaluating path losses in the internal links of the modeled CDMA system. Please see the separate information page regarding the choice and settings of the propagation models.