LTE Signaling
R&S
®
CMW-KM5xx/-KS5xx
56
User Manual 1173.9628.02 ─ 16
2.2.14.4
Follow WB CQI-RI and CQI-PMI-RI Channels
The scheduling type "Follow WB CQI-RI" is only relevant for the transmission mode 3,
scheduling type "Follow WB CQI-PMI-RI" only for the transmission mode 4. Option
R&S CMW-KS510/-KS512 is required (without CA/with CA).
The downlink signal reacts to the reported values.
The reported CQI index value determines the MCS index value used for the downlink.
The dependency between CQI and MCS is configured via a mapping table, as for "Fol-
low wideband CQI". The resource block settings are also similar to the "Follow wide-
band CQI" settings.
The reported Rank Indicator (RI) value determines the used transmission scheme. For
RI=2 spatial multiplexing is used. For RI=1 transmit diversity is used.
For scheduling type "Follow WB CQI-PMI-RI", the used PMI value follows the reported
PMI value.
Subframe 0 and 5 are not scheduled for duplex mode FDD. For TDD, UL/DL configura-
tion 2 is used and only downlink subframe 3, 4, 8 and 9 are scheduled. This complies
with the reference channel definition for CQI tests, as defined in 3GPP TS 36.521,
Table C3.2-4.
2.2.15 Semi-Persistent Scheduling (SPS)
Applications like voice over LTE require constant but few radio resources. Voice data is
sent in small packets that are transmitted in regular intervals.
For such applications, semi-persistent scheduling (SPS) can be used instead of
dynamic scheduling. This reduces the control channel overhead on the PDCCH, so
that a cell can handle more voice calls in parallel. With SPS, the UE gets a semi-per-
sistent grant. The grant allows the UE to use every n
th
subframe until further notice.
The LTE signaling application supports SPS in transmission mode 1 and 2, uplink and
downlink.
The configuration of the resource block allocation is similar to the configuration for a
user-defined channel, see
chapter 2.2.13, "User-Defined Channels"
on page 51. The
rules for the allowed number of RBs and position of the first RB are identical.
In contrast to user-defined channels, SPS does not support 64-QAM modulation. The
maximum transport block size index is 14, see following table.
Table 2-11: Range of transport block size index depending on modulation type
Modulation Type
QPSK
16-QAM
64-QAM
Indices for uplink channels
0 to 10
10 to 14
not supported
Indices for downlink channels
0 to 9
9 to 14
not supported
The configured resource block allocation is granted every n
th
subframe, where n is con-
figurable between 10 and 640.
General Description
深圳德标仪器
135-1095-0799