Transmission (PDSCH, 6GR)
The group of the PDSCH tab. All parameters are auto-coupled — see Auto and Manual Parameter Coupling.
These parameters determine which DMRS ports are active, and so how many layers the PDSCH Physical Downlink Shared Channel carries. The active set can either be listed explicitly or decoded from a DCI antenna-port table row.
DMRS Ports - Selects which mechanism determines the active DMRS ports. 3GPP TS Technical Specification 38.212 §7.3.1.1.2 defines a DCI field named “Antenna port(s)” whose value is a table row index that decodes to a set of DMRS ports; this setting chooses whether that lookup or an explicit port list applies.
- Port List - The active ports are the explicit list in Port List.
- Table Index - The active ports are decoded from the DCI table row selected by the Table Index cell, which appears beside the selector only while this choice is selected, and written back into Port List. The upper limit of the index depends on Enhanced DMRS Type, DMRS Max Length, and DMRS Configuration, since those choose which table applies.
Default: Port List; table index 0
Choices: Port List, Table Index
Port List - Sets the active DMRS ports, as a list or range (for example, ). PDSCH ports are numbered from 1000, per 3GPP. Available for editing while DMRS Ports is Port List; in the other mode it reports the ports the measurement decoded from the DCI table row.
Number of Codewords / Layers - One row holding two values. Number of Codewords sets the number of codewords (transport blocks) this PDSCH carries. A second codeword is what allows more than four DMRS ports — and therefore more than four layers — to be configured (3GPP TS 38.212). It is only permitted when the DMRS configuration can carry them, so 2 is reduced to 1 unless DMRS Max Length is 2, DMRS Configuration is Type2, or at least four DMRS ports are in use. It is an input only while DMRS Ports is Table Index, where it selects the table block the index is read from; otherwise it is derived from the DMRS port count and shown read-only. Number of Layers is read-only and reports the number of transmission layers in use, which reflects the number of active DMRS ports.
Default: Number of Codewords Auto — two codewords above four ports, otherwise one
Choices (codewords): 1, 2
Reference DMRS Port - Selects the DMRS port used as the baseline for relative power, phase, and timing measurements. This is a measurement setting, not part of the transmitted signal definition. The available choices are the ports that are both legal for the current DMRS configuration and in the active Port List.
Default: Auto — the first port in Port List
CDM Group(s) w/o Data - Sets the number of DMRS CDM groups without data. Valid values are 1 to 2 for DMRS config Type1 and 1 to 3 for Type2. Decoded from the antenna-port table while DMRS Ports is Table Index; settable when it is Port List.
Default: 1
Range: 1 to 3
See Also
