8.3 General settings

• Introduction
• 8.3.1 CDMA general settings
• 8.3.2 Local environment
• 8.3.3 Receiver settings
• 8.3.4 Transmitter settings
• 8.3.5 CDMA uplink
• 8.3.6 CDMA downlink
• 8.3.7 CDMA capacity
• 8.3.8 Propagation Model

Introduction

The General settings tabsheet contains a range of CDMA system parameters as well as some parameters that depend on the modelled direction of CDMA link (uplink vs. downlink). 7 panels characterised the CDMA system. The below graphic represent the CDMA UL when a victim.

 

Figure 187: CDMA UL general settings

 

The only differences with CDMA DL are the following 2 panels (CDMA Downlink and CDMA Capacity).

Figure 188: CDMA DL general settings difference with CDMA UL

8.3.1 CDMA general settings

Table 27: CDMA general settings input parameters

 

8.3.2 Local environment

You can choose the suitable indoor and outdoor ratio for the mobile station to be used by the propagation model. Further details are presented in Section ‎5.4.3.

8.3.3 Receiver settings

This content of this panel depends whether CDMA system is a victim or an interfering system. If the CDMA is a victim, you will have to set the blocking mask. It is a shared interface with OFDMA.

Figure 192: Cellular panel receiver settings

 

Table 27: Receiver settings of a cellular system

 

8.3.4 Transmitter settings

This content of this panel depends whether CDMA system is a victim or an interfering system.  If the CDMA is an interferer, you will have to set the spectrum emission mask and the emissions floor. It is a shared interface with OFDMA.

 

Figure 190: Cellular panel transmitter settings

 

When defining the Emission Mask (not as BEM) the units of the user defined mask are: Offset (MHz); Mask Values (dBc); Reference Bandwidth (kHz).

When defining the Emission mask as a Block Edge Mask (BEM), SEAMCAT sets to 0 dBi the peak gain of the transmitter antenna and uses the power entries of the Mask as e.i.r.p (already including the gain of the antenna). So, if the Emission mask is defiend as BEM, the units of the user defined mask are: Offset (MHz); Mask Values (dBm e.i.r.p.); Reference Bandwidth (kHz).

8.3.5 CDMA uplink

This is only available if CDMA UL selected.

 

8.3.6 CDMA downlink

This panel is available only if CDMA DL selected.

 

 

8.3.7 CDMA capacity

The capacity of the simulated system (i.e. how many mobiles per cell should be generated in the system) is dependent on all other settings and cannot always be easily deducted from these. Therefore SEAMCAT has a feature that allows for automatic determination of capacity. This is also known as simulation of non interfered capacity and is enabled by default. 

 

In CDMA UL, the number of optimised users is being re-calculated for each event. It is recommended to run the "simulate non-interfered capacity" so that SEAMCAT can provide a "best" optimised value, this will optimise the computation time afterwards. If you are using another number you risk to create an overhead in your computation time without any change in the output results.

 

 

 

Description	Symbol	Type	Unit	Comments
Simulate non interfered capacity	-	Boolean	-	Toggles automatic capacity finding. 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 (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, you are free to set a constant user-defined average number of mobile users per cell especially if the optimal capacity for the current scenario is known (this is often the case when running consecutive simulations with the same system) there is no need to simulate – as the simulation process can be quite lengthy. When this checkbox is disabled SEAMCAT uses the value entered in 2 – “Users per cell” as the capacity per cell.
Init users per cell	-	Scalar	-	If capacity simulation is enabled this indicates the starting point of the simulation. Selecting the right starting point can speed up the capacity finding. If capacity simulation is disabled the value in this field is the actual value used by SEAMCAT. SEAMCAT does NOT change this input value into the result of the simulation! Users per cell is equal to UE per Base Station. SEAMCAT consider each Base station as its own cell.
Delta users per cell		Scalar	-	When SEAMCAT tries to find the optimal capacity it adjust the number of UEs per cell starting with this value. A proper value here can speed up capacity finding.
Number of trials		Scalar	-	When finding the optimal capacity SEAMCAT runs this (i.e. Number of trials) many snapshots of every value of UEs per cell before deciding whether or not the current value is the optimal capacity. Generally larger numbers mean greater precision but also longer time needed by the algorithm.
Target noise rise precision		Scalar	dB	Uplink only – the precision used when comparing the noise rise of the filled system with target noise rise set under the “CDMA Uplink” panel
Tolerance of initial outage		Scalar	%	Downlink only – The tolerance of initial outage is the percentage of UEs that can be dropped before SEAMCAT determines that the tested number of UEs cannot fit into the system (i.e. 20 user_per_cell * 19 BS = 380 UEs, if 5% or less of 380 UEs are dropped, the system is considered able to handle/service 20 UEs per cell). SEAMCAT will adjust the value of UEs per cell untill a value is found which in 80% of the specified number of trials is able to handle the tested number of UEs per cell.This parameter allows for UEs in “extreme” pathloss situations to be “ignored” from the optimal capacity finding.

8.3.8 Propagation Model

You can choose the suitable propagation model to be applied when calculating signal loss along the transmitter and the receiver path. A choice and settings of propagation models are presented in ‎ANNEX 17:.