Page 105 - Kaleidoscope Academic Conference Proceedings 2020

Industry-driven digital transformation

are multiple interference cells, the MMSE-IRC weighting short’ type of time-frequency resource is more suitable for
matrix formula can be extended as follows: cell edge UEs. As a result, dynamic scheduled resources are
different between cell center UEs and cell edge UEs. Figure
−1

= � + ∑ + 0 � (3) 3 shows an example of the gNB allocating resources to cell

center UEs and cell edge UEs for the BCI method. In Figure
3, the RUR is divided into 7×4 resource sub-blocks by 2-D
3. MULTIPLEXING METHODS bitmap with a size of 28 bits. The first green resource in RUR
is allocated to a cell edge UE by gNB, which occupies two
In Figure 2, an example of BCI for UL multiplexing resource sub-blocks in the time domain and only one in the
transmission is shown. The resource for grant-based eMBB frequency domain. The second green resource block in the
and URLLC is scheduled by UL grant #1 and UL grant #2 RUR is allocated to a cell center UE by gNB, which occupies
respectively. Meanwhile, a URLLC resource indication can only one resource sub-block in the time domain and three
be transmitted to an eMBB UE by the UL CI. The eMBB UE resource sub-blocks in the frequency domain. Furthermore,
should cancel its uplink transmission when the UL CI is different use cases are identified for URLLC services, such
detected. In this case, the resource region in which the as power distribution, factory automation and transport
URLLC cancellation resource indicated by the UL resource industry, etc. In accordance with different traffic
indication is named as reference uplink resource (RUR). characteristics, different resource allocations are required for
different use cases. For example, a service with a larger
A BPC for UL multiplexing transmission is another packet size and higher reliability requirement expects more
alternative, i.e. boosting the URLLC transmission power on resource allocation compared with a smaller packet size or
the colliding resources. When one UE already is transmitting lower reliability requirement. In the actual network
an eMBB physical uplink shared channel (PUSCH) and then deployment, various URLLC services could coexist in one
another UE has urgent URLLC data to be sent on the same cell.
resource, a relatively higher power can be applied than for
the case without overlapping eMBB transmission. For the
power control scheme, the gNB can still receive the eMBB Downlink
transmissions. The URLLC transmission may have
interference on the eMBB transmission, but it can still be
possible for the gNB to decode the eMBB transmission block
correctly without a retransmission. Uplink

URLLC RUR
UE
UL grant #1 UL grant #2 Resource scheduled for
UL URLLC
Resource cancelled by
gNB UL CI falsely
Figure 3 – Allocated resources to cell center UEs and cell
edge UEs for BCI method
eMBB
UE The resource indication pattern under BCI is configured
semi-statically, i.e., 4×7 resource sub-blocks as shown in
UL grant #1 UL grant #2 UL CI Resource indicated by
UL CI Figure 3. A semi-static 2-D bitmap pattern cannot provide
Resource scheduled Resource scheduled flexible frequency domain granularity indication, which
for URLLC UE for eMBB UE causes a large number of eMBB transmissions to be
Figure 2 – An example of BCI multiplexing method cancelled falsely. From the overall performance, the loss
outweighs the gain. In order to make better use of spectrum
3.1 Design for DPCI resources in different scenarios for URLLC and reduce the
probability of eMBB being canceled by error, dynamic
URLLC UEs are randomly distributed at both the center and configuration of the resource indication pattern should be
edge in a cell. For cell center UEs, it is reasonable to allocate supported. Instead of using the indication bits to indicate the
a ‘thin-tall’ type of time-frequency resource for latency frequency resource occupation uniformly for all time
reduction. While for URLLC UEs located at the edge of the domain occasions, only the time domain occasions occupied
cell which are subject to greater inter-cell interference and by URLLC PUSCH are valid for further frequency
larger path loss, higher power is expected to meet the indication in DPCI. Thus, the occupied time domain
reliability requirement. It tends to allocate less frequency occasions are indicated firstly, and the time-frequency
resource to such UEs due to a power limitation issue, instead resource corresponding to the occupied time domain
more symbols have to be scheduled to them. Then, a ‘fat-

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