This is presentation is based on a research paper titled "USING NOMA FOR ENABLING BROADCAST/UNICAST CONVERGENCE IN 5G NETWORKS" published in IEEE TRANSACTIONS ON BROADCASTING, VOL. 66, NO. 2, JUNE 2020.

1. Malaviya National Institute of Technology Jaipur
USING NOMA FOR ENABLING
BROADCAST/UNICAST
CONVERGENCE IN 5G
NETWORKS
Presented By :
RAJAT YADAV
2021PEC5640

2. KEY OUTLINES
BASIC IDEA OF PAPER
WHAT IS NOMA
INTRODUCTION
5G OVERVIEW
5G NOMA
PHY EVALUTAION
NETWORK SIMMULATION
CONCLUSIONS

3. BASIC IDEA OF THIS PAPER
Author proposes a novel solution for 5G -NR
Commmunication based on Power domain - Non
Orthogonal Multiple Access (P-NOMA)
Different system configurations are analysed and
evalution tests are performed.
Perfomance tests are done on network simmulation
tools.
Results for capacity, latency and reliability are compared
for different multiple access techniques.

4. WHAT IS P-NOMA
THERE ARE TWO TYPES OF MULTIPLE ACCES TECHNIQUE MAINLY :
ORTHOGONAL MULTIPLE ACCESS TECHQNIQUES(OMA)
NON-ORTHOGONAL MULTIPLE ACCESS TECHNIQUES (NOMA)
NOMA, allows allocating one frequncy channel to multiple users at the
same time.
Two types of NOMA Technique:
Power Domain NOMA and Code Domain NOMA
Power Domain NOMA :
superposes multiple user in power domain
exploits channel gain between difference multiplexed users.

5. WHAT IS P-NOMA
At Transmitter Side:
Signals from various are superposed.
Resulting Signal is transmitted over same channel (same time-
frequency resources)
At Receiver Side:
Multi User Detection algorithms, such as Succesive Interference
Cancellation (SIC) are utilised to detect desired signals.

6. WHAT IS P-NOMA

7. INTRODUCTION
Radiocommunication Sector of International Telecommunication Union
(ITU- R) has divided entire application frame into 3 use case :
Enhanced Mobile Broadband (eMMB) [related to classic information &
entertainment delivery, high data rates are required(upto
20GBPS),supports speed upto 500km/hr]
Ultra Reliable Low Latency Communication (URLLC) [related to critical
communication, one milisecond end to end latency required]
Massive Machine Type Communications (mMTC) [high device density
like 10^6 devices per km^2]

8. INTRODUCTION

9. INTRODUCTION
One system may not be efficient for another application.
This gives opportunity to 5G -NR as it can act as a main generic solution
for wireless communication.
NOMA can be implemented to deliver simultaneously different services,
assuming diverse power levels and configuration.
100% of RF bandwidth is used 100% of time to transmit two or more
service.
NOMA is considered more spectrally efficient as compared to
TDMA,OFDMA.

10. 5G OVERVIEW
Like 4G, 5G-NR is based on OFDM.
Main novelity of 5G-NR is its configuration flexibilty.
There are five numerologies (u) available with different subcarrier
spacing (SCS)
Each radio frame has fixed length of 10ms.
Each frame is composed of 10 subframe.
Each subframe has a duration of 1ms.

11. 5G OVERVIEW
Default no. of symbols per slot is 14.
In order to transmit short data packet, a mini slot configuratin can be
implemented where 2,4,7 symbols can be used.
On the other hand, slot can be gathered for longer data packet.

12. 5G OVERVIEW
The main PHY level novelty from reliabilty pov is new channel codding.
LDPC and Polar Codes are supported.
Polar codes are reserved for control packet transmission.
LDPC codes are used in payload data packets
Regarding MAC layer implementation, several things are directly
inherited for LTE.
Like LTE, 5G-NR use HARQ techniques for error correction.
Main difference is, in 5G the HARQ response time is flexible. In 4G, it
was fixed to 4ms.

13. 5G NOMA
The proposed prototype is partially compliant with NR Rel-15 standard.
Transreceiver is developed in MATLAB.

14. 5G NOMA
Two independent data flows are created, one per each NOMA layer.
A Downlink Shared Channel (DL-SCH) transport channel is generated
for each layer.
LDPC coding is applied.
Once PDSCH are generated for both layer, they are combined into a
single NOMA signal ensemble.
Symbols corresponding to LL are attenuated by predefined IL.
The IL indicates the relative power distribution between both layer.
IL = 10.log(g) , where g can be [0,1)
g=0 for single layer system and g=1 for two layer system.

15. 5G NOMA
Transmitted signal is filtered through channel model.
Ideal Channel Model with AWGN Noise and a Tapped Delay model is
used.
At receiver, first module perform OFDM demodulation and channel
estimation.
For UL recovery, demodulation is done. The UL noise threshold is low
so, LL will be assumed as noise for UL.
To recover LL, successive interference cancellation(SIC) is required.
Output of SIC module is difference of both signals, ie LL.

16. 5G NOMA

17. PHY Evaluation
P-NOMA offers a new dimension for system flexibility, the capacity and
the robustness as per requirements.
P-NOMA offers a new dimension for system flexibility, the capacity and
the robustness as per requirements.
IL = -6 dB for NOMA1 and IL =-18dB for NOMA2
Broadcast uses UL and Unicast used LL.

18. NETWORK SIMMULATION
The system evaluation has been carried out in an upgraded OMNeT++.
This network simulation tool is composed of both PHY and MAC layers
for each of the implemented transmitters and receivers.
PHY layer module facilitates the selection of the parameters that define
the waveform.
MAC layer, HARQ type retransmission schemes are implemented.
The implemented channel profile are (TDL-D or TDL-E).
Different mobility models are available in OMNeT++ for different type
of receivers.

19. NETWORK SIMMULATION

20. RESULTS
Evaluation is done on 3 KPI’s : reliability, latency and throughput.
To measure reliability, PER is used as metric.
For latency, User plane latency is evaluated. UPL is defined as required
time to deliver a data Next Node(gNB) and user equipment (UE).
For measuring throughput, two metrics are used: normalized data
reception index (NDRI) and effective throughput. The NDRI indicates the
relation between the amount of information received and the maximum
information rate that could be received in the error free case.

21. RESULTS

22. RESULTS

23. CONCLUSION
This paper proposes a PHY/MAC enabler solution forbroadcast and
unicast convergence in 5G NR.
The system configuration parameters have been analyzed, and different
configuration options have been discussed.
This flexibility has been used to increase the reliability of the unicast
receivers and to deliver higher data rate to the unicast receivers.

24. THANKS
FOR YOU
ATTENTION