Resource Allocation in OFDM Based Wireless Relay Networks ...

More documents

Recommendations

Info

Chapter 3 Resource Optimization in Bidirectional Relay Networks In this chapter, we study resource optimization in multi-user bidirectional relay networks. Based on the studies in previous chapter, we derive an asymptotically optimal solution for joint resource optimization and further design a low complexity algorithm to trade the performance for computational complexity. Finally, simulation results are provided to demonstrate the performance gain of the proposed algorithms. 3.1 Introduction Overview Most of the existing communication systems are bidirectional such that the roles of the source node and the destination node alternate from time to time. In a relay aided scenario, the bidirectional transmission can be simply achieved by applying twice the principle of relaying scheme from each direction. Let U 1 and U 2 be the two users who can communicate with each other through a relay station R. Due to half duplex nature of relay terminals, the traditional relaying transmission requires four phases for a complete bidirectional transmission round as shown in Fig. 3.1. 43
3.1 Introduction A new technology called TWRN has been developed in [41], [42]. The TWRN Figure 3.1: Bidirectional communication with OWRN. exploits the recently developed advanced coding techniques [43] to overcome the spectral efficiency loss caused by the half-duplex constraint in the one-way relay network (OWRN). Compared with the conventional one-way relay partner, two-way communication provides an improved spectral efficiency with a two phase protocol, where in the first phase, the two terminals simultaneously transmit their signals to the relay node, and in the second phase the relay transmits the received signals to both ends. A simple three-node TWRN is shown in Fig. 3.2, where one round of data communication is divided into two phases. During Phase t 1 , signals are sent out simultaneously from both U 1 and U 2 , and then are superimposed at the R. During Phase t 2 , the relay broadcasts the received signals to both terminals. Since U i ’s i = 1, 2 know their transmitted signal in the first phase, they can subtract the self-signal component from the received signal and recover the desired information. Compared with four phases transmission, bidirectional relay transmission significantly enhances the transmission throughput [42], [43]. Related Work Shannon first studied the two way relay channel in [44] and recently a number of two way relaying protocols for AF and DF schemes have been proposed in the literature [45]–[47]. Considering multiple relay nodes, distributed space time coding scheme and the opportunistic relaying scheme have been presented in [48] and [49]. Resource allocation techniques in OFDM based TWRNs have been proposed in [50]–[55]. The authors in [50] studied the throughput maximization problem in a 44
Page 1 and 2:
Resource Allocation in OFDM Based W
Page 3 and 4:
Dedications: To my family
Page 5 and 6:
Acknowledgment I am greatly thankfu
Page 7 and 8: Contents 2.3.3 Proposed Low-Complex
Page 9 and 10: Abstract The combination of relay t
Page 11 and 12: List of Tables 3.1 Complexity compa
Page 13 and 14: List of Figures 4.1 System model fo
Page 15 and 16: List of Acronyms IEEE MU RS AWGN OW
Page 17 and 18: 1.1 Overview of Relay Networks wire
Page 19 and 20: 1.2 Overview of OFDM Figure 1.2: Th
Page 21 and 22: 1.3 Basics of the Optimization Theo
Page 23 and 24: 1.3 Basics of the Optimization Theo
Page 25 and 26: 1.4 Resource Allocation Problem is
Page 27 and 28: 1.5 Contribution and Organization o
Page 29 and 30: 1.5 Contribution and Organization o
Page 31 and 32: 2.1 Introduction allocated to a nod
Page 33 and 34: 2.1 Introduction The main contribut
Page 35 and 36: 2.2 System Model where h m,k denote
Page 37 and 38: 2.3 Resource Allocation Schemes opt
Page 39 and 40: 2.3 Resource Allocation Schemes ( )
Page 41 and 42: 2.3 Resource Allocation Schemes and
Page 43 and 44: 2.3 Resource Allocation Schemes tha
Page 45 and 46: 2.3 Resource Allocation Schemes 2.3
Page 47 and 48: 2.4 Generalization to Multiple Rela
Page 49 and 50: 2.4 Generalization to Multiple Rela
Page 51 and 52: 2.5 Simulation Results • OptSol/J
Page 53 and 54: 2.5 Simulation Results 0.9 0.85 0.8
Page 55 and 56: 2.6 Summary 2.6 2.4 2.2 2 Rate (bit
Page 57: 2.6 Summary 2.4 2.2 2 1.8 N=4 N=3 N
Page 61 and 62: 3.1 Introduction • Broadcast Phas
Page 63 and 64: 3.2 System Model MU MU 3 8 A 1 2 7
Page 65 and 66: 3.4 Joint Resource Allocation Schem
Page 67 and 68: 3.4 Joint Resource Allocation Schem
Page 69 and 70: 3.5 Step-Wise Low-Complexity Resour
Page 71 and 72: 3.6 Simulation Results and SNR B m,
Page 73 and 74: 3.6 Simulation Results 3 2.5 2 Uppe
Page 75 and 76: 3.7 Summary 1.8 1.6 1.4 JntOpt SubO
Page 77 and 78: 4.1 Introduction • Non-orthogonal
Page 79 and 80: 4.3 Cooperative Non-Orthogonal Tran
Page 87 and 88: 4.4 Optimization under Orthogonal T
Page 89 and 90: 4.4 Optimization under Orthogonal T
Page 91 and 92: 4.5 Simulations Then, the over all
Page 93 and 94: 4.5 Simulations 40 30 20 Sum−ρ S
Page 95 and 96: 4.6 Summary 0.9 0.8 0.7 JPSC Pow EP
Page 97 and 98: Chapter 5 Lifetime Maximization in
Page 99 and 100: 5.1 Introduction Figure 5.2: Linear
Page 101 and 102: 5.2 System Model antenna that canno
Page 103 and 104: 5.4 Lifetime Maximization Scheme 5.
Page 105 and 106: 5.4 Lifetime Maximization Scheme wh
Page 107 and 108: 5.5 Simulation Results 150 OPT−SO
Page 109 and 110:
5.6 Summary Lifetime (S) 150 100 50
Page 111 and 112:
Chapter 6 Resource Allocation in Co
Page 113 and 114:
7. Conclusions were considered for
Page 115 and 116:
Bibliography [12] A. Peled, and A.
Page 117 and 118:
Bibliography [36] Z. Luo and S. Zha
Page 119 and 120:
Bibliography [61] D. H. N. Nguyen,
Page 121 and 122:
Bibliography [84] A. Goldsmith, S.
Page 123 and 124:
Bibliography [105] Y. Li, W. Wang,
Page 125 and 126:
Appendix A Derivations of Closed-Fo
Page 127:
B. Derivations of the Optimal Power
show all

Resource Allocation in OFDM Based Wireless Relay Networks ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?