Assuming ideal case, the basic proposal of a CR is as follows:
if sRSS > Detection threshold -> WSDOFF = no transmission = no interference
if sRSS < Detection threshold -> WSDON = interference calculation is possible
STEP 1: Identification of the frequencies to be tested.
It is assumed that the frequency of the interfering WSD is dependent on the frequency range defined for the victim. This means that when the CR module is activated, the interfering frequency function dialogue box is deactivated.
M is the number of possible channels that the WSD will operates in.
One can consider following possible ways to define operating frequency for the victim device:
Victim frequency = constant
- interferer frequency = Victim frequency;
- M = 1
victim frequencies are discrete;
- the possible WSD frequencies that you defined;
- M equals the number of discrete inputs victim frequencies are distributed between fmin and fmax;
- The possible WSD frequencies are from fmin+(M-1)*victim bandwidth until fmax (i.e. assuming that f is the center frequency). Note that (fmin+(M-1)*victim) ≤ fmax;
- Extract M WSD channels.
STEP 2: Assigned the WSD with a frequency
for each event{
Note: the victim operates at a single frequency fv. Several interferers may be operating in various frequencies
if (dRSS > sensitivity){
for each WSDs {
for channel m = 1 to M+1(i.e. over all the WSD channels){
STEP 2.1: Calculate the sRSS
- Calculate the sRSS (considering the unwanted mask of the DTT) at the channel m (i.e. WSD at fm and victim at fv) (see ANNEX 6:)
STEP 2.2: Identification of “available” channels
- Detect if a WSD is allowed to transmit (i.e. compare to threshold)
- Store the channels that are accessible as vector available_channel
- Store the channels that are not accessible as vector non_available_channel
}
STEP 3: Probability of Failure (if activated)
- Failure status (either TRUE or FALSE) of this WSD is extracted as an event from a distribution. i.e. depending of the pfailure
- If this WSD has failure = TRUE, then it means that it will transmit in the victim frequency without power constraint
- Update the vectors available_channel and non_available_channel so that non_available channel= 0 and available_channel=1 and is the victim frequency.
- If this WSD has failure = FALSE, proceed without changing the vectors available_channel and non_available_channel
STEP 4: Select an available channel / determination of the WSD channel
if (non_available_channel < 1) (i.e. all are available){
- No frequency is blocked, the max e.i.r.p. of the WSD is considered (i.e. e.i.r.p. deduced from the Tx and antenna gain of the WSD which are inputs to SEAMCAT.)
- The WSD is placed randomly among the available_channel
}
else (i.e. one or more channels are blocked (i.e. non-available)){
if (all channels are blocked){
try another WSD à back to STEP 2.1 and store the number of inactive WSD
}
else (not all the channels are blocked){
if (single frequency case) (i.e. frequency = constant){
No frequency is blocked, the max e.i.r.p of the WSD is considered (i.e. e.i.r.p deduced from the Tx and antenna gain of the WSD which are inputs to SEAMCAT.)
}
else {
Step 4.1: Apply the Table of Constraints
For each of the non_available_channel, read the associated predefined table for which the “co-channel” row is synchronised to the non-available channel. Create a new e.i.r.p table with the dimension (number of rows: number of non_available_channel, number of columns: number of available_channel).
for each of the available_channel{
- Extract the lowest e.i.r.p from the table. This gives the vector (available channel, e.i.r.p).
Step 4.2: Determination of the WSD channel /e.i.r.p
- From this vector extract the couple (fi, “max e.i.r.p”) the vector (available channel, e.i.r.p)
- if several channels are associated with the same “max e.i.r.p” , the WSD is placed randomly among the channels.
}
}
}
}
} (end of the WSD loop)
Note: Now the active WSDs are assigned a frequency and a e.i.r.p..max.
STEP 5: Cumulate the frequency/ e.i.r.p of all the active WSDs for each event into a single vector.
Note: The below calculation is as normal to SEAMCAT
for each active WSDs {
Extract the Tx power = e.i.r.p max - GmaxIt→VLR
Calculate iRSSunwanted (i.e. victim at fv )
Calculate iRSSblocking (i.e. victim at fv )
Calculate iRSSoverlaoding from the interfering WSD to the at the DTT victim link receiver frequency.
}
Calculate the (Eq. 178)
Calculate the (Eq. 179)
Note: If none of the WSDs are active iRSScomp = -1000 dB (by default) to allow the interference calculation.
}
else{
Skip this event
}
}