LTE-Advanced: How is the PMI used by multi-antenna UE ?

Question

In release 11: When E-PDCCH is transmitted in PDSCH, does the subframe still allocate the same amount of resource for PDCCH?

Answer 1

The reason for the PMI in DL MIMO is twofold:

UE uses PMI, that is provided in DCI with other allocation information for DL MIMO operation to “deprecode” the signal. In that case the eNB precodes the transmitted PDSCH data for that UE with the use of selected PMI and tells the UE which one it has selected;
UE calculates the best suited PMI and tells the eNB which one to use for following TTIs and reports within a feedback message.

You may find more detailed information about PMI and other feedback under the following links/posts:

http://4g-university.com/recent-answers/lte-ue-feedback-reporting-cqipmiri/

http://4g-university.com/recent-answers/lte-feedback-cqi-pmi-and-ri-relations/

http://4g-university.com/recent-answers/lte-feedback-subband-pmi-report/

http://4g-university.com/recent-answers/lte-ul-feedback-periodic-and-aperiodic-cqi-subband-reporting/

http://4g-university.com/recent-answers/lte-ul-cqi-pmi-ri-reporting-interval-in-cqi-periodicaperiodic-reports/