| 1. |
- Advaita, Advaita, et al.
(author)
-
Outage Probability of MIMO Cognitive Cooperative Radio Networks with Multiple AF Relays Using Orthogonal Space-Time Block Codes
- 2017
-
In: 2017 IEEE 13TH INTERNATIONAL CONFERENCE ON WIRELESS AND MOBILE COMPUTING, NETWORKING AND COMMUNICATIONS (WIMOB). - : IEEE. - 9781538638392 ; , s. 84-89
-
Conference paper (peer-reviewed)abstract
- In this paper, we analyze the outage probability of multiple-input multiple-output cognitive cooperative radio networks (CCRNs) with multiple opportunistic amplify-and-forward relays. The CCRN applies underlay spectrum access accounting for the interference power constraint of a primary network and utilizes orthogonal space-time block coding to transmit multiple data streams across a number of antennas over several time slots. As such, the system exploits both time and space diversity to improve the transmission reliability over Nakagami.. fading. The CCRN applies opportunistic relaying in which the relay offering the highest signal-to-noise ratio at the receiver is selected to forward the transmit signal. Furthermore, selection combining is adopted at the secondary receiver to process the signal from the direct and relaying transmissions. To evaluate system performance, we derive an expression for the outage probability which is valid for an arbitrary number of antennas at the source, relays, and receiver of the CCRN. Selected numerical results are provided using Mathematica for analysis and Matlab for simulations, to reveal the effect of network parameters on the outage probability of the system.
|
|
| 2. |
- Chu, Thi My Chinh, et al.
(author)
-
Analysis of Variance of Opinion Scores for MPEG-4 Scalable and Advanced Video Coding
- 2018
-
In: 2018 12TH INTERNATIONAL CONFERENCE ON SIGNAL PROCESSING AND COMMUNICATION SYSTEMS (ICSPCS). - : IEEE. - 9781538656020
-
Conference paper (peer-reviewed)abstract
- In this paper, we conduct an analysis of variance (ANOVA) on opinion scores for MPEG-4 scalable video coding (SVC) and advanced video coding (AVC) standards. This work resorts on a publicly available database providing opinion scores from subjective experiments for several scenarios such as different bit rates and resolutions. In particular, ANOVA is used for statistical hypothesis testing to compare two or more sets of opinion scores instead of being constrained to pairs of sets of opinion scores as would be the case for t-tests. As the ANOVA tests of the different scenarios are performed for mean opinion scores (MOS), box plots are also provided in order to assess the distribution of the opinion scores around the median. It is shown that the opinion scores given to the reference videos in SVC and AVC for different resolutions are statistically significantly similar regardless of the content. Further, for the opinion scores of the considered database, the ANOVA tests support the hypothesis that AVC generally outperforms SVC although the performance difference may be less pronounced for higher bit rates. This work also shows that additional insights on the results of subjective experiments can be obtained by extending the analysis of opinion scores beyond MOS to ANOVA tests and box plots.
|
|
| 3. |
- Chu, Thi My Chinh, et al.
(author)
-
Capacity Analysis of Two-Tier Networks with MIMO Cognitive Small Cells in Nagakami-m Fading
- 2017
-
In: 2017 IEEE 13TH INTERNATIONAL CONFERENCE ON WIRELESS AND MOBILE COMPUTING, NETWORKING AND COMMUNICATIONS (WIMOB). - : IEEE. - 9781538638392 ; , s. 457-463
-
Conference paper (peer-reviewed)abstract
- In this paper, we consider a two-tier cellular network consisting of a primary macro cell base station (PMBS) which is overlaid by cognitive small cell base stations (CSBSs) to achieve efficient spectrum utilization. The deployment of two-tier cellular networks can provide higher capacity for the system but also causes cross-tier, intra-tier, and inter-tier interference within the cellular networks. Thus, we employ transmit and receive beamforming in the considered two-tier cellular network to mitigate interference. We first design the receive beamforming vector for a primary user (PU) such that it cancels all inter-tier interference from other PUs. Then, the transmit beamforming vectors at the secondary users (SUs) are designed to null out the cross-tier interference to the PUs. Further, the receive beamforming vectors at the SUs are designed to mitigate the crosstier interference from the PUs to the SUs. Finally, the transmit beamforming vector at the PMBS is designed to maximize the signal-to-interference-plus-noise ratio at the PUs. To quantify the performance of the system, we derive an expression for the channel capacity in the downlink from the CSBSs to the SUs. Numerical results are provided to reveal the effect of network parameters such as intra-tier interference distances, fading conditions, and number of antennas on the channel capacity of the SUs.
|
|
| 4. |
- Chu, Thi My Chinh, et al.
(author)
-
Channel Reservation for Dynamic Spectrum Access of Cognitive Radio Networks with Prioritized Traffic
- 2015
-
In: 2015 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATION WORKSHOP. - : IEEE Communications Society. - 9781467363051 ; , s. 883-888
-
Conference paper (peer-reviewed)abstract
- In this paper, we propose a strategy to coordinate the dynamic spectrum access (DSA) of different types of traffic. It is assumed that the DSA assigns spectrum bands to three kinds of prioritized traffic, the traffic of the primary network, the Class 1 traffic and Class 2 traffic of the secondary network. Possessing the licensed spectrum, the primary traffic has the highest access priority and can access the spectrum bands at anytime. The secondary Class 1 traffic has higher priority compared to secondary Class 2 traffic. In this system, a channel reservation scheme is deployed to control spectrum access of the traffic. Specifically, the optimal number of reservation channels is applied to minimize the forced termination probability of the secondary traffic while satisfying a predefined blocking probability of the primary network. To investigate the system performance, we model state transitions of the DSA as a multi-dimensional Markov chain with three-state variables representing the number of primary, Class 1, and Class 2 packets in the system. Based on this chain, important performance measures, i.e., blocking probability and forced termination probability are derived for the Class 1 and Class 2 secondary traffic.
|
|
| 5. |
- Chu, Thi My Chinh, et al.
(author)
-
Downlink outage analysis for cognitive cooperative radio networks employing non-orthogonal multiple access
- 2018
-
In: 2018 IEEE 7th International Conference on Communications and Electronics, ICCE 2018. - : Institute of Electrical and Electronics Engineers Inc.. - 9781538636787 ; , s. 27-32
-
Conference paper (peer-reviewed)abstract
- In this paper, we employ power-domain non-orthogonal multiple access (NOMA) to simultaneously transmit signals to both a primary user (PU) and a secondary user (SU) of a cognitive cooperative radio network (CCRN). Higher priority is given to the PU over the SU by keeping the power allocation coefficients at the base station (BS) and relay (R) above a certain threshold. In this way, similar as the interference power limit imposed by the PU in a conventional underlay CCRN, the power allocation coefficients at the BS and R of the CCRN can be controlled to maintain a given outage performance. Analytical expressions of the cumulative distribution function of the end-to-end signal-to-interference-plus-noise ratios at the PU and SU are derived and then used to assess the outage probabilities of both users. Numerical results are presented to study the impact of system parameters on outage performance of the CCRN with power-domain NOMA. In addition, it is illustrated that increased downlink performance can be obtained by combining power-domain NOMA with CCRNs. © 2018 IEEE.
|
|
| 6. |
- Chu, Thi My Chinh, et al.
(author)
-
Full-Duplex Cooperative NOMA Short-Packet Communications with K-Means Clustering
- 2023
-
In: IEEE Workshop on Statistical Signal Processing Proceedings. - : IEEE Computer Society. - 9781665452458 ; , s. 576-580
-
Conference paper (peer-reviewed)abstract
- Fifth-generation (5G) and future sixth-generation (6G) mobile networks aim at offering ultra-reliable, low-latency, and massive machine-type communications. In this context, this paper studies full-duplex (FD) cooperative non-orthogonal multiple access (C-NOMA) short-packet communications (SPC) with K-means clustering of user equipment regarding block error rate (BLER) and sum rate. Analytical expressions are derived for the BLER and sum rate allowing to assess the performance of the considered system. The numerical results reveal the benefits of the FD C-NOMA SPC system, illustrate trade-offs between BLER and sum rate, and show the impact of the transmit signal-to-noise ratio and number of channel uses on the performance. © 2023 IEEE.
|
|
| 7. |
- Chu, Thi My Chinh, et al.
(author)
-
MAC Protocol for Opportunistic Spectrum Access in Multi-Channel Cognitive Relay Networks
- 2017
-
In: IEEE Vehicular Technology Conference. - : Institute of Electrical and Electronics Engineers Inc.. - 9781509059324
-
Conference paper (peer-reviewed)abstract
- In this paper, we propose a medium access control (MAC) protocol for multi-channel cognitive cooperative radio networks (CCRNs). In this protocol, each secondary user (SU) senses for spectrum opportunities within M licensed bands of the primary users (PUs). To enhance the accuracy of spectrum sensing, we employ cooperative sequential spectrum sensing where SUs mutually exchange their sensing results. Moreover, the information obtained from cooperative spectrum sensing at the physical layer is integrated into the channel negotiation process at the MAC layer to alleviate the hidden terminal problem. Finally, the performance of the proposed MAC protocol in terms of aggregate throughput of the CCRNs is analyzed. Numerical results are provided to assess the impact of channel utilization by PUs, number of contenting CCRNs, number of licensed bands, and false alarm probability of SUs on the aggregate throughput. © 2017 IEEE.
|
|
| 8. |
- Chu, Thi My Chinh, et al.
(author)
-
Modeling and Analysis of Small Cell Networks with NOMA : A Stochastic Geometry Approach
- 2021
-
In: IEEE ICCE 2020. - : IEEE. ; , s. 105-110
-
Conference paper (peer-reviewed)abstract
- In this paper, a stochastic geometry approach is used to model and analyse a downlink small cell network (SCN). Carrier sense multiple access with collision avoidance (CSMA/CA) is used as medium access control (MAC) protocol at the base stations (BSs). To boost spectral efficiency, each active BS deploys both orthogonal multiple access (OMA) and nonorthogonal multiple access (NOMA) to transmit signals to the user equipments (UEs) in its coverage area. The choice between OMA and NOMA mode is based on the density of UEs and aims to improve the sum rate of the BS. If there exist two UEs that sufficiently differ in their channel power gains to the BS, the BS will use NOMA superimposing the signals of the UEs in the power-domain. Otherwise, the BS will operate in OMA mode to transmit the signal of a single UE in its coverage area. Stochastic geometry is used to include the spatial densities of the UEs and BSs in the performance assessment of the SCN. On this basis, analytical expressions for the coverage probability, data rates of the UEs, and sum rate of the BSs of the considered system are derived. Numerical results are provided to illustrate the impact of system parameters on the performance of this SCN with NOMA subject to the spatial densities of the BSs and UEs.
|
|
| 9. |
|
|
| 10. |
- Chu, Thi My Chinh, et al.
(author)
-
NOMA-Based Full-Duplex UAV Network with K-Means Clustering for Disaster Scenarios
- 2022
-
In: IEEE Vehicular Technology Conference proceedings. - : Institute of Electrical and Electronics Engineers (IEEE). - 9781665454681
-
Conference paper (peer-reviewed)abstract
- In this paper, we propose and assess the performance of a downlink non-orthogonal multiple access (NOMA)based full-duplex (FD) unmanned aerial vehicle (UAV) network for disaster scenarios. The K-means algorithm is used to partition the user equipments (UEs) residing in the disaster region into a number of clusters. The UAVs are located at the cluster centers and act as decode-and-forward relays to secure coverage from an operational base station (BS) into the disaster region. The power-domain NOMA used at the BS and the UAVs operating in FD mode improve the system performance in terms of outage probability and sum rate compared to orthogonal multiple access and half-duplex mode. In particular, analytical expressions for the outage probability and sum rate are derived. Numerical results are provided to reveal the impact of system parameters on the performance of the NOMA-based FD UAV network over Nakagami-m fading which in turn illustrate design options for applications in disaster scenarios. © 2022 IEEE.
|
|
