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Introduction
3 elements form the path between the VLR and the VLT or the ILR and ILT as illustrated in Figure 148. Figure 148: Transmitter to Receiver Path illustration Figure 149: Transmitter to Receiver Path GUI
5.4.1 Relative location
When the Correlated distance option is checked, the positions of the receiver and transmitter are geographically fixed with respect to each other (e.g. co-located or constantly spaced base stations). The transmitter is considered a reference centre. When t...
5.4.2 Coverage radius
A coverage radius is calculated for both the victim link and the interfering link. It is the for the victim link (VLR-VLT) and the for the interfering link (ILR-ILT) (see Annex A13.1). The receivers will be randomly deployed within the area centred on th...
5.4.3 Local environment
The percentage of transceivers being indoor and outdoor can be selected thanks to this panel. It will work in combination with the chosen propagation model that you will select. By default the transmitter and receiver are located outdoor. For each elements of ...
5.4.4 Propagation Model
A suitable propagation model can be selected to be applied when calculating signal loss along the path between transmitters and receivers. Further information on propagation models are presented in detail in ANNEX 17.
6 Spectrum sensing and cognitive radio
6.1 Introduction
Cognitive radio is a technology which is being developed to bring greater efficiency, speed and reliability to users of wireless devices. The number of high powered wireless devices coming on to the market is increasing exponentially placing an unprecedented d...
6.2 Simulating spectrum sensing
The manual sets out how SEAMCAT can be used for spectrum sensing where the interfering devices (ILT) try to detect the presence of protected services (e.g. the VLT) transmitting in each of the potentially available channels. Spectrum sensing essentially involv...
6.3 Input system parameters
For the sensing feature to be activated, both the victim and interferer transmitters have to have the “interferer is CR” selected (Figure 158). This will activate the spectrum sensing algorithm (see ANNEX 16:) and will allow you to set the transmitting charact...
6.4 Scenario parameters
In addidtion to the input system parameters, you also need to set charateristics of the spectrum sensing algorithm as described in Section 10.4.
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6.5 Examples
At the end of the simulation, SEAMCAT provides a set of output vectors as presented in Section 12.4. The following subsections present examples on how to interpret the results.
6.5.1 All the channels are available
In such a scenario, the detection threshold is taken to a value of 0 dB (Figure 160) much higher than the sRSS level (average = -82.09 dBm) (Figure 161). Therefore, no victim system has been detected and the WSDs are allowed to transmit in any of the specif...
6.5.2 All the channels are blocked
In such a scenario, the detection threshold is taken to a lower value compared to the sRSS and none of the WSDs are transmitting. In SEAMCAT, the Tx power is set to -1000 dBm (Figure 166). The WSD frequency is the same as the victim frequency per event. Figur...
6.5.3 Some of the channels are blocked and some are available
This is a typical example. In such a scenario, the detection threshold is taken to a value of -80 dB (flat over the frequency range). This mean that when considering the sRSS of Figure 168, for some of the events, the sRSS will be above that threshold and ther...
7 Cellular network simulation
7.1 Introduction
Whereas traditional simulation of non-CDMA or non-OFDMA systems is carried out in SEAMCAT by taking two pairs of transmitters-receivers and estimating signals received between them separately (i.e. without any form of feed-back influence), the simulation of ce...
7.2 CDMA overview
When simulating CDMA systems, SEAMCAT performs power controlling in a fully loaded system of all the MSs so that the impact from the neighbourhing two tiers is included (inter-cell interference), for victim CDMA systems, and the system level-out the inter-cell...