Channel state Information reference signal (CSI-RS)
This module generates the channel state information reference signal (CSI-RS) based on the inputs passed and map this signal to time-frequency (t-f) resource grid as per Section 7.4.1.5 of [3GPPTS38211_csirsRM]. THis resource grid can be orthogonal frequency division multiplexed (OFDM) and transmitted over the wireless channels.
Generating CSI-RS Resource Grid:
subcarrierSpacing = 30000
startPRB = 2
nrofPRBs = 8
numSubcarriers = 12*(nrofPRBs+startPRB)
Nfft = 128
## CSI-RS Resource Configurations___
rowIndex = 5
nrofPorts = 4
density = 1
cdmType = "fd-CDM21"
## CSI-RS Parameters__________________________________________
scramblingID = 13254
numSlotsPerFrame = int(10*(subcarrierSpacing/15000))
slotNumber = 5
#_____________________________________________________________
## Time and Frequency resources____________________
betaCSIRS = 1
firstOFDMSymbolInTimeDomain = 2
firstOFDMSymbolInTimeDomain2 = None
frequencyDomainAllocation = np.array([0,0,1,0,0,0])
## CSI-RS Resource mapping
rmCSIRS = ResourceMapperCSIRS(nrofPorts, density, cdmType, scramblingID, slotNumber)
csirsGrid = rmCSIRS(betaCSIRS, frequencyDomainAllocation, firstOFDMSymbolInTimeDomain,
firstOFDMSymbolInTimeDomain2, nrofPRBs, startPRB, Nfft)
Display the CSI-RS Resource Grid:
fig0, ax0 = rmCSIRS.displayResourceGrid()
Display the CSI-RS CDM Grid:
fig1, ax1 = rmCSIRS.displayCDMPattern()
- class toolkit5G.ResourceMapping.ResourceMapperCSIRS(nrofPorts, density, cdmType, scramblingID, slotNumber, frequencyDomainAllocation=None, firstOFDMSymbolInTimeDomain=0, firstOFDMSymbolInTimeDomain2=None, rowIndex=None)[source]
Generates the resource grid for CSI-RS as per Section 7.4.3 [3GPPTS38211_SSBGrid].
- Parameters:
nrofPorts (int) – Defines number of ports \(\in \{1,2,4,8,12,16,\) \(24,32\}\).
density (int) – Defines the density of CSI-RS \(\in \{0.5,1,3\}\).
cdmType (int) – Defines the CDM Type \(\in \{\text{"noCDM"}, \text{"fd-CDM2"}\), \(\text{"fd-CDM21"}, \text{"cdm4-FD2-TD2"}, \text{"cdm8-FD2-TD4"}\}\).
scramblingID (int) – Defines the scramblingID \(\in \{0,1,\dots,4095\}\).
slotNumber (int) – Defines the slot number within a frame \(n_{s,f}^{\mu} \in \{0,1,2,\) \(\dots,10*2^{\mu}-1\}\) where \({\mu = \frac{\Delta f}{15 kHz}}\).
frequencyDomainAllocation ([N,], int) – Defines frequencyDomainAllocation (default value = None) used for selecting \(k_i\). It is used for determining REs(Resource Elements) for the selected CSI-RS.
firstOFDMSymbolInTimeDomain (int) – Defines firstOFDMSymbolInTimeDomain (default value = 0) used for selecting \(l_0\). It is used for determining OFDM symbol Indices for the selected CSI-RS.
firstOFDMSymbolInTimeDomain2 (int) – Defines firstOFDMSymbolInTimeDomain2 (default value = None) used for selecting \(l_1\). It is used for determining OFDM symbol Indices for the selected CSI-RS.
Important
The combination of
nrofPorts,densityandcdmTypeshall be selected based on Table 7.4.1.5.3-1 of [3GPPTS38211_csirsRM].Important
For row 5 and 7 of Table 7.4.1.5.3-1 from [3GPPTS38211_csirsRM]
cdmTypeshould be configured as “fd-CDM21”.- Input:
nrofPRBs (int) – Defines number of physical resource blocks (PRBs) allocated for CSI-RS transmission.
startPRB (int (default value = 0)) – Defines starting physical resource blocks (PRBs) from where next nrofPRBs are occupied by CSI-RS.
resourceGridSizeinRBs (int) – Defines the size of CSI-RS Resource Grid in units of resou (default value = None).
beta (float) – Defines power scaling factor (default value = 1) of CSI-RS.
- Output:
[numBatches, nrofPorts, 14, numSubcarrier], np.complex64 – Channel state information Reference Signal (CSI-RS) Grid.
- Raises:
ValueError – [Error in ResourceMapperCSIRS]: firstOFDMSymbolInTimeDomain must be an integer from interval [0,13]!
ValueError – Invalid choice for cdmType!
Warning – [Warning in ResourceMapperCSIRS]: firstOFDMSymbolInTimeDomain2 is redundant!
ValueError – [Error in ResourceMapperCSIRS]: firstOFDMSymbolInTimeDomain2 must be an integer from interval [2,12]!
ValueError – [Error in ResourceMapperCSIRS]: firstOFDMSymbolInTimeDomain2 must be passed for ‘Row’ = ” + str(self.__rowIndex) + “!
ValueError – [Error in ResourceMapperCSIRS]: For rowIndex = ” + str(self.__rowIndex) + “, length of FrequencyDomainAllocation must be ” + str(numSCmap[self.__rowIndex]) + “!
ValueError – [Error in ResourceMapperCSIRS]: Elements of frequencyDomainAllocation must be 0 or 1!
ValueError – [Error in ResourceMapperCSIRS]: frequencyDomainAllocation must be integer or integer array!
ValueError – [Error in ResourceMapperCSIRS]: rowIndex must take an integer from interval [1,18]!
ValueError – [Error in ResourceMapperCSIRS]: rowIndex must be integer or integer array!
ValueError – [Error in ResourceMapperCSIRS]: numSubcarrier must be a positive integer!
ValueError – [Error in ResourceMapperCSIRS]: numSubcarrier is inconsistent with (startPRB, nrofPRBs)!
ValueError – [Error in ResourceMapperCSIRS]: numSubcarrier must be a positive integer!
ValueError – [Error in ResourceMapperCSIRS]: startPRB must be a positive integer!
ValueError – [Error in ResourceMapperCSIRS]: nrofPRBs must be a positive integer!
ValueError – [Error in ResourceMapperCSIRS]: For nrofPorts = ” + str(self.__nrofPorts) + ” and density = ” + str(self.__density) + “, cdmType must take value from set: ” + str(possibleCDMtype) + ” !
ValueError – [Error in ResourceMapperCSIRS]: For nrofPorts = “+str(self.__nrofPorts)+”, density must take value from set: “+str(possibleDensity)+” !
ValueError – [Error in ResourceMapperCSIRS]: nrofPorts must be interger taking value from set {1,2,4,8,12,16,24,32} !
ValueError – Error: Number of REs per symbols can’t be more than 2!
ValueError – Invalid Length of frequencyDomainAllocation!
ValueError – Invalid number of symbols configured for CSI-RS!
- References: