Browsing by Author "Chang, Min-Kuan"

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35 An Effective Routing Protocol with Guaranteed Route Preference for Mobile Ad Hoc Networks
(2014)
Chien, Feng-Tsun
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Wu, Kuo-Guan
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Chan, Yu-Wei
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Chang, Min-Kuan
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Su, Yi-Sheng
Battery power and queue conservation are critical issues in mobile ad hoc network (MANET). These two factors not only affect the delivery ratio but also the lifetime of the network. In this work, we will propose a simple and effective routing protocol to extend the lifetime and to evenly distribute the traffic loads of the networks as possible. Furthermore, a concept of serving capacity is introduced to reflect the level of congestion around a node. In this way, the proposed routing protocols can avoid network congestion and achieve higher packet delivery ratios. The extensive computer simulation is conducted to compare the proposed protocol against many existing routing protocols. The results show that the proposed routing protocol can have better performance in terms of queueing length, lifetime, and packet delivery ratio and have comparable end-to-end delays.
A Coalitional Graph Game Approach for Minimum Transmission Broadcast in IoT Networks
(2020-01-01)
Chan, Yu-Wei
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Chien, Feng-Tsun
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Chang, Min-Kuan
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Ho, Wei-Chun
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Hung, Jason C.
In this work, we consider the broadcast mechanisms for both reliable links and unreliable links in the Internet of Things (IoT) networks. Focusing on the minimum transmission broadcast (MTB) problem, we propose an efficient algorithm, termed as the Connected Dominating Set Algorithm based on Coalitional Graph Game (CDSA-CGG), to find the minimum connected dominating set (MCDS). Distinct from related work in the literature which adopts a non-cooperative game approach and assumes the interaction among nodes is limited to neighboring nodes, we formulate the interaction and cooperation among nodes over reliable links and over unreliable links as a connected forwarding graph based on coalitional graph game. We prove that the forwarding graph constructed by CDSA-CGG is a Nash network. In addition, we also prove that the final resulting graph is pairwise stable. The simulation results show that the proposed coalition graph game-based algorithm performs well in terms of the number of transmissions, convergence rate, and lifetime of nodes.
A Content-Adaptive Image Enlargement Scheme Based on Iterative Back-Projection
(2014-01-01)
Chang, Min-Kuan
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Su, Ming-Cheng
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Lin, Guo-Shiang
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Chien, Feng-Tsun
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電子工程學系及電子研究所
In this paper, we propose an adaptive image enlargement scheme based on iterative back-projection. Initial estimates of each enlarged image can be individually created from the spatial and temporal domains by using sub-pixel interpolation and sub-pixel motion estimation. Then, based on the initial estimates and image content, reconstructed images are derived by using a modified iterative back-projection technique and fused into an enlarged image. Finally, a low-pass filter as a post-processing is applied to reduce the blocking artifacts in the reconstructed high-resolution images. Our experiment results demonstrate that, in terms of PSNR and NQM, the proposed scheme is superior to existing methods.
Adaptive Modulation in Decode-and-Forward Cooperative Communications With Limited Source-Relay CSI
(2014-12-01)
Chang, Min-Kuan
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Chien, Feng-Tsun
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
In this letter, we study the problem of adaptive modulation (AM) in cooperative decode-and-forward (DF) relaying systems with limited channel state information (CSI) of the source-relay link. We first develop the signal-to-noise ratio (SNR)-based opportunistic AM and obtain the regions of the source-destination and relay-destination link SNR, by which whether cooperative relaying is needed and what constellation size should be chosen can be determined without requiring the source-relay link CSI. We also propose the probabilistic AM to further enhance the transmission rate. Simulation results demonstrate the effectiveness of the proposed AM criteria.
Coalitional Game Formulation for Multi-Channel Cooperative Cognitive Radio Networks
(2011)
Chan, Yu-Wei
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Chang, Ronald Y.
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Chien, Feng-Tsun
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Chang, Min-Kuan
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Chung, Yeh-Ching
In this paper, we study a coalitional game approach to resource allocation in a multi-channel cooperative cognitive radio network with multiple primary users (PUs) and secondary users (SUs). We propose to form the grand coalition by grouping all PUs and SUs in a set, where each PU can lease its spectrum to all SUs in a time-division manner while the SUs in return help the data transmission of PUs by relaying. The grand coalition is shown to be stable in the considered scenario by justifying that the solution concept of the coalitional game (the core) is nonempty. Also, optimal relay strategies of SUs, to relay or to transmit its own data, are obtained so that the sum rate of all PUs and SUs is maximized. Finally, we demonstrate in simulation the benefits of the grand coalition comparing to the case of direct transmission only and other forms of coalitions as well.
Cooperative Online Caching in Small Cell Networks with Limited Cache Size and Unknown Content Popularity
(2018-01-01)
Yen, Chen-Tai
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Chien, Feng-Tsun
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Chang, Min-Kuan
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
In this paper, we study delay-aware cooperative online content caching with limited caching space and unknown content popularity in dense small cell wireless networks. We propose a Cooperative Online Content cAching algorithm (COCA) that decides in which BS the requested content should be cached with considerations of three important factors: the residual cache space in each small cell basestation (SBS), the number of coordinated connections each SBS establishes with other SBSs, and the number of served users in the coverage area of each SBS. In addition, due to limited storage space in the cache, the proposed COCA algorithm eliminates the least recently used (LRU) contents to free up the space. We compare the delay performance of the proposed COCA algorithm with the existing offline cooperative caching schemes through simulations. Simulation results demonstrate that the proposed COCA algorithm has a better delay performance than the existing offline algorithms.
Generation of Two-Dimensional Optical Reference Signals Based on Parametric Minimum Cross Entropy
(2011-06-15)
Su, Yi-Sheng
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Wu, Tsung-Cheng
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Wang, Chung-Hsuan
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Chang, Min-Kuan
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電機工程學系
In this letter, a novel design of two-dimensional (2-D) zero reference codes (ZRCs) based on parametric minimum cross entropy (PMCE) is proposed to generate 2-D optical zero reference signals (ZRSs) with low second maximum for grating alignment systems. An optical ZRS is necessary to obtain an absolute measurement in grating alignment systems. A method to acquire an optical ZRS is by means of illuminating two identical superimposed ZRCs. Because the movement between the two ZRCs is in two-axis, 2-D ZRCs are required. However, they are hard to design due to the high computational complexity, especially for large codes. The proposed PMCE method not only reduces the second maximum of 2-D optical ZRSs, but also decreases the computational complexity. Simulation results indicate that there are 8.33%similar to 22.22% reductions in the second maximum of several 2-D optical ZRSs, as compared with those of the recently proposed cross-entropy (CE) method. The PMCE method proves to be a powerful tool for the design of 2-D ZRCs.
How Repeated Games with Unequal Discount Factors Affect the Cooperation Behavior in DF Cooperative Communication Systems
(2017-01-01)
Chang, Min-Kuan
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Chen, Ting-Chen
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Chien, Feng-Tsun
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this work, the repeated game model with unequal discount factors is utilized to understand how the players' behavior affect the system performance in a decode-and-forward cooperative communication system. Unlike previous work, in which all free-ridings are illegal, we differentiate the free-riding into the legal free-riding (LFR) and the illegal one (IFR). Taking LFR and IFR into account, the conditions for the case which players cooperate to be a NE and to be the only NE in the proposed repeated games are established as well when the discount factors of players are not equal, which are then confirmed through extensive computer simulations.
Joint User Clustering and Content Caching with Heterogeneous User Content Preferences
(2019-01-01)
Chiu, Feng
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Kuo, Ting-Yu
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Chien, Feng-Tsun
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Huang, Wan-Jen
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Chang, Min-Kuan
In this paper, we consider a joint design of the user clustering and content caching in the cache-enabled heterogenous network (HetNet) in which users in the network have distinct content preferences. The joint clustering and caching in the HetNet relies on multitude of factors, such as channel gains in all links, which may not be fully known in practice. Besides, clustering and caching may exhibit a fundamental tradeoff between the content hit probability and the spectral efficiency. We are therefore motivated to tackle this challenging problem by the deep reinforcement learning (DRL). In particular, the deep deterministic policy gradient (DDPG) algorithm is employed to manage the dynamics of clustering and caching in the HetNet with a sizable action space. Simulation results are presented to demonstrate the effectiveness of the proposed algorithm.
On the Accumulated Loopback Self-Interference of Two-Way Full-Duplex AF Relaying Systems
(2019-05-01)
Chang, Min-Kuan
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Chien, Feng-Tsun
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Kuo, Chih-Hung
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Chen, Yen-Chang
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交大名義發表
Two-way full-duplex (TWFD) transmissions in cooperative amplify-and-forward (AF) relaying systems provide a promising way of communications with the improved spectral efficiency by concurrently transmitting/receiving data in the same frequency band and by the two-way transmission protocol. However, the loopback self-interference, caused by the imperfect channel estimation in the loopback link, at the AF relay accumulates and is forwarded to the end users recurrently, which substantially degrades the end users' error performance if this accumulated loopback self-interference (ALSI) does not converge. It is therefore of critical importance to analyze the convergence behavior of the ALSI in the TWFD systems with AF relaying. In this paper, we establish sufficient conditions on the relay power to ensure the convergence of the ALSI, with which the average limiting signal-to-interference-plus-noise ratio at the infinite time horizon is derived. In addition, we specify the relay power at which the signal-to-noise ratio reaches the maximal value under different scenarios and obtain an upper bound to the symbol error rate. Finally, extensive computer simulations results are provided to corroborate the analytic derivations.
Relay Selection in Multiuser Two-Way Cooperative Relaying Systems
(2012)
Liao, Yi-Ju
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Chien, Feng-Tsun
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Chang, Min-Kuan
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
In this paper, we study a relay selection (RS) problem in multi-user two-way cooperative relaying systems. We consider a more practical scenario in which multiple users, multiple relays and a single destination are involved in the two-way network. In this paper, the code division multiple access (CDMA) system with non-orthogonal spreading sequences is employed to handle the multiuser interference. Relay selection based on maximizing the SINR of the worse link is proposed in this research. Besides, aiming at mitigating the interference, we consider the design of linear filter at each relay such that the minimum SINR of the worst link in the two-way transmission is maximized. The result shows that the linear filter is similar to minimum mean-square error (MMSE) detector. Furthermore, we simulate the proposed scheme with several different parameters such as the numbers of users and relays, and the length of spreading sequences. Also, we compare the proposed RS method with random RS approach, and the result shows that our proposed method has better performance in terms of the bit error rate (BER).
Spectrum sharing in multi-channel cooperative cognitive radio networks: a coalitional game approach
(2013-10-01)
Chan, Yu-Wei
;
Chien, Feng-Tsun
;
Chang, Ronald Y.
;
Chang, Min-Kuan
;
Chung, Yeh-Ching
In this paper, we study a coalitional game approach to resource allocation in a multi-channel cooperative cognitive radio network with multiple primary users (PUs) and secondary users (SUs). We propose to form the grand coalition by grouping all PUs and SUs in a set, where each PU can lease its spectrum to all SUs in a time-division manner while the SUs in return assist PUs' data transmission as relays. We use the solution concept of the core to analyze the stability of the grand coalition, and the solution concept of the Shapley value to fairly divide the payoffs among the users. Due to the convexity of the proposed game, the Shapley value is shown to be in the core. We derive the optimal strategy for the SU, i.e., transmitting its own data or serving as a relay, that maximizes the sum rate of all PUs and SUs. The payoff allocations according to the core and the Shapley value are illustrated by an example, which demonstrates the benefits of forming the grand coalition as compared with non-coalition and other coalition schemes.
Stochastic Game-Theoretical Power Allocation in D2D Communications
(2016)
Chang, Min-Kuan
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Chien, Feng-Tsun
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Chen, Ting-Chen
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Li, Kuan-Lin
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電子工程學系及電子研究所
In D2D communication, power allocation is important due to interference among D2D users. In this paper, we model the power allocation problem in D2D environment as a stochastic game and find the Nash equilibrium. The simulation shows the workability and correctness of the proposed stochastic power allocation game.