Note: This page has been translated by MathWorks. Please click here

To view all translated materals including this page, select Japan from the country navigator on the bottom of this page.

To view all translated materals including this page, select Japan from the country navigator on the bottom of this page.

EPDCCH DM-RS resource element indices

`ind = lteEPDCCHDMRSIndices(enb,chs)`

`ind = lteEPDCCHDMRSIndices(enb,chs,opts)`

returns
indices of the Enhanced Physical Downlink Control Channel Demodulation
Reference Signal (EPDCCH DM-RS) resource elements (RE) associated
with an EPDCCH transmission candidate in a subframe. By default, `ind`

= lteEPDCCHDMRSIndices(`enb`

,`chs`

)`ind`

is
a column vector of indices in one-based linear indexing form. Use
this form to directly index the EPDCCH DM-RS REs of an *N*-by-*M*-by-4
array that represents the subframe resource grid across the four possible
EPDCCH antenna ports (*p* = 107...110). You can also
generate alternative index representations. The order of the indices
is the same as required for the complex EPDCCH DM-RS symbols mapping. `lteEPDCCHDMRS`

generates these symbols.

The indices are parameterized in terms of a configured PRB pair set which defines:

the overall set of possible EPDCCH candidates and

the aggregation of one or more consecutive enhanced control channel elements (ECCE). This aggregation identifies the specific EPDCCH instance that the DM-RS are associated with.

The DM-RS indices are created only for the specific PRB pairs and antenna ports that the corresponding EPDCCH is mapped to. They do not account for any external precoding operations.

For a localized EPDCCH transmission, the EPDCCH is associated
with a single antenna port from *p* = 107...110,
dependent on the `RNTI`

and ECCEs selected. Thus,
the DM-RS antenna port indices (1...4 respectively, if one-based)
are output for that single port.

For a distributed transmission, the EPDCCH is mapped to two
antenna ports in an alternating fashion. Therefore, the DM-RS indices
are generated for the PRBs in both ports: *p* = 107,109
for normal cyclic prefix and *p* = 107,108 for extended
cyclic prefix. The output is ordered so that the symbols for the lowest
antenna index plane come first. These indices are suitable for indexing
an *N*-by-*M*-by-4 array representing
the subframe resource grid across the four possible EPDCCH antenna
ports (*p* = 107...110).

This syntax returns an NRE length column vector of one-based
linear indices for the DM-RS resource elements associated with a particular
EPDCCH candidate. The function is initialized according to the cell-wide
settings, `enb`

, and the EPDCCH transmission configuration, `chs`

.

Was this topic helpful?