subcarrier bit and power allocation in multiuser ofdm systems

... 2: EQUIVALENCE OF BIT- FILLING AND BIT- REMOVAL CONCLUSIONS In this work, we surveyed the area of bit and power loading in constrained multicarrier communication systems in the single-user context ... providing a tutorial survey on the bit and power loading in constrained multicarrier systems and at reviewing the most popular results on the loading algorithms for the RM and MM problems We examine ... optimum bit allocation profile of a continuous greedy bit- filling process, where any total power or peak -power constraints are at the moment ignored In other words, if bit- filling is continuously...

Ngày tải lên: 22/06/2014, 19:20

... considered combined use of CCI mitigation and power allocation in a multiuser MIMO relay system In this paper, we consider coordinated transmission for the CCI mitigation and power allocation in a correlated ... shadowing effect [2] The transmit beamforming and receive combining vector for user i can be determined in a similar manner Proposed Coordinated Transmission In this section, we design a coordinated ... maximum power allocation (RMMSE-CBF+Max PA ) [15], the noncoordinated eigen-beamforming with maximum power allocation (RNC-Eig.BF+Max PA ) [28], and the singular value decomposition and ZF beamforming...

Ngày tải lên: 21/06/2014, 17:20

... Tianjin, China, in 1998, and his M.Eng degree in telecommunications engineering from Beijing University of Posts and Telecommunications, Beijing, China, in 2001 He is currently a Ph.D student in ... increasing total power consumption by properly removing some nodes in S and adjusting transmission power of the remaining nodes First, for level L, ΓL = {N }, thus |ΓL | = Suppose that for decoding ... noncooperative path using standard Dijkstra’s algorithm based on the link-based metric and then use the power allocation policy in Theorem to determine the overall power consumption and possibly remove...

Ngày tải lên: 22/06/2014, 22:20

... scheduling algorithm It is intended to improve Best Channel by maintaining a balance between two competing interests: maximizing the total wireless network throughput while allowing a minimum ... 4, pp 409–410, 2006 [3] R Knopp and P A Humblet, “Information capacity and power control in single-cell multiuser communications,” in Proceedings of the IEEE International Conference on Communications ... constraint given in terms of a delay constraint and a BER The delay constraint consists of a target delay Dt and the probability of exceeding it, ε Three simple and widely employed disciplines...

Ngày tải lên: 21/06/2014, 11:20

... system of interest uses OFDM symbols with KU < N subcarriers for the data transmission The remaining N − KU subcarriers serve as a guard band The time domain samples are computed using the well-known ... and frequency offset in OFDM systems, ” IEEE Transactions on Signal Processing, vol 45, no 7, pp 1800– 1805, 1997 [4] T M Schmidl and D C Cox, “Robust frequency and timing synchronization for OFDM, ” ... tones spaced by Dt = 10 OFDM symbols and by D f = subcarriers [11] Their pattern is shown in Figure Generated OFDM symbols are 3.1 Coarse Timing Synchronisation Downlink timing synchronisation should...

Ngày tải lên: 21/06/2014, 22:20

... be used in OFDM systems to support multiple mobile terminals With many subcarriers available in OFDM systems, an intuitive way is dividing the subcarriers into several groups and assigning a group ... mixed integer non-linear programming (MINLP) with nonlinearities in both the objective function and constraints We propose a method to convert the MINLP to an equivalent binary linear programming ... present a method to convert the MINLP to an equivalent binary linear programming (BLP), by exploiting some properties of the subcarrierand -bit allocation (SBA) in OFDM systems The BLP can reduce CPU...

Ngày tải lên: 10/09/2015, 15:49

... follows waterfilling on channel SNR, that is, Pi increases with increasing ζi ; and for ζi > ζi(o) , the power allocation is according to inversion in the channel SNR, that is, increasing ζi decreases ... Communications and Networking power allocation problem simple and easy to compute as will be seen in the ensuing development Note that the resulting design for power allocation can be viewed as a joint ... considering the spatial correlation In this paper, we present a novel framework which incorporates adaptive power allocation (APA) in the network by taking into account the spatial correlation and...

Ngày tải lên: 21/06/2014, 17:20

... Communications and Networking User λ1 Removal scheme Real subcarrier allocation User λ2 User K λk PHY-layer subcarrier and power allocation Subcarrier MAC-layer requirements & initial scheduling users' ... performance for real-time users in multiuser OFDM systems References [1] E Lawrey, Multiuser OFDM, ” in Proceedings of the International Symposium on Signal Processing and Its Applications (ISSPA ... based on packet scheduling, and multiple frequency subcarrier scheduling, which may be implemented in multiuser OFDM systems, is not considered In the PHY layer, the total power resource is limited...

Ngày tải lên: 21/06/2014, 20:20

... retransmission number We introduce the variable a taking values in {1, 2}, where a = and a = mean, respectively, the incoming and outgoing links being active a will be called the scheduling variable or ... carry out an internal minimization step which is used for rate selection and power allocation for the subintervals within a cycle at the active link This internal minimization leads to an independent ... and/ or low power consumption and so forth For our example with the given parameters, the opportunistic scheduling policy is given as a= if incoming link is “good,” if incoming link is “bad” and...

Ngày tải lên: 22/06/2014, 19:20

... classified in: Point-to-Multipoint (PMP) scheduling mechanisms and Mesh scheduling mechanisms Moreover, some scheduling works are focused on downlink scheduling, others on uplink scheduling, and others ... broadcasted to all SSs and an SS only picks-up the packets destined to it The uplink Scheduling Mechanisms scheduling is more complex than downlink scheduling In the uplink scheduling, the input queues ... Godoy Junior and Augusto Foronda Chapter Scheduling Algorithm and Bandwidth Allocation in WiMAX 85 Majid Taghipoor, Saeid MJafari and Vahid Hosseini Chapter Downlink Resource Allocation and Frequency...

Ngày tải lên: 21/06/2014, 05:20

... uplink traffic strongly depends on the CAC algorithm Scheduling has also been studied intensively in many disciplines, such as CPU task scheduling in operating systems, service scheduling in ... Table Main parameters of the simulation 99 Scheduling Algorithm and Bandwidth Allocation in WiMAX In particular, we consider several comparable scheduling algorithms, including WRR, EDF, and TRS ... for the remaining users under high SINR assumption 114 Quality of Service and Resource Allocation in WiMAX Will-be-set-by -IN- TECH 10 3) Power minimization with individual rate constraints Now assume...

Ngày tải lên: 21/06/2014, 05:20

... resource allocation in wireless c networks: Theory and algorithms, Springer Thanabalasingham, T., Hanly, S V., Andrew, L L H & Papandriopoulos, J (2006) Joint allocation of subcarriers and transmit powers ... user k in bands I, P A resp sharing factors of user k in bands I, Pc resp power allocated to user k in bands I, P A resp power transmitted by base station c in bands I, P A resp total power transmitted ... approximating function Moreover, subcarrier assignment is performed independently (and thus suboptimally) in each cell assuming equal power allocation and equal interference level on all subcarriers...

Ngày tải lên: 21/06/2014, 05:20

... 16: Air interface for fixed and mobile broadband wireless access systems amendment 2: Physical and medium access control layers for combined fixed and mobile operation in licensed bands and corrigendum ... by the constraining and restricting services, there are different strategies of bandwidth allocation and admission control Many bandwidth allocation policies have been developed in order to give ... the bandwidth unit allocated to accepted calls in the system and the Adaptive Modulation and Coding scheme (AMC) 148 Quality of Service and Resource Allocation in WiMAX Will-be-set-by -IN- TECH...

Ngày tải lên: 21/06/2014, 05:20

... Combined Fixed and Mobile Operation in Licensed Bands Jeffrey G et al (2007) Fundamentals of WiMAX Understanding Broadband Wireless Networking, Prentice Hall Communications Engineering and Emerging ... structure defined in the IEEE 802.16 standard for TDD in PMP mode is shown in Fig Each frame has a duration of Δ and is divided into uplink and downlink subframes At the beginning of a downlink subframe, ... fixed and mobile broadband wireless access In the standard (IEEE 802.16 standard, 2009), it defines several air interface variants, including WirelessMAN-SC, WirelessMAN -OFDM, WirelessMAN-OFDMA and...

Ngày tải lên: 21/06/2014, 05:20

... downlink and uplink schedulers located at BS, and responsible for managing the flows in the downlink and uplink respectively, and subscriber station schedulers, which together manage flows in the ... three fields: initial ranging (Ranging), bandwidth requests (BW-REQ) and specific slots Initial ranging is used by SSs to discover the optimum transmission power, as well as the timing and frequency ... Quality of Service and Resource Allocation in WiMAX Will-be-set-by -IN- TECH J G Andrews; A Ghosh & R Muhamed (2007) Fundamentals of WiMAX: Understanding Broadband Wireless Networking, Prentice Hall,...

Ngày tải lên: 21/06/2014, 05:20

... WiMAX and LTE The emphasis is put on the main differences in handling QoS in both 4G systems Even though the underling technologies differ in many aspects, it is important to Evaluation of QoS and ... (ACM) Applications usually express their bandwidth requirements in bits (bytes) per second In OFDM/ OFDMA systems utilizing ACM each user can use coding and modulation scheme most appropriate to ... and compare this methodology with standardized SLS simulation approaches In Section a description of ns-2 and Matlab integration using Link-To-System (L2S) mapping can be found Additionally information...

Ngày tải lên: 21/06/2014, 05:20

... protocol suite The operating layer is able to classify the incoming SDU by addressing to cross-layer table for inserting the correct information in the defined header field to inform lower layer of ... illustrated in Fig.1.3 In this figure, a Base Station (BS) is fully responsible for Up Link (UL) and Down Link (DL) traffic scheduling Virtual UL scheduling process is integrated into the BS ... MBpsec in optimal conditions In addition, the diversified and powerful QoS-supported platform adopted in WiMAX allows handling numerous data types in conformance with specific telemedicine applications...

Ngày tải lên: 21/06/2014, 05:20

... & Schulzrinne) IP/UDP/RTP packet interleaving scheme which includes FEC as separate packets, and it is worth considering how application layer packet interleaving could be included in the presented ... user, which is a minimum of one per link direction In a MHz system, the maximum is 17 uplink and 15 downlink sub-channels For a 10 MHz system (FFT size 1024) 35 downlink and 30 uplink sub-channels ... to 3G systems, which bandwidth capacity will be further expanded in part ‘m’ of the standard (Ahmandi, 2011, written by Intel’s chief technology officer) Broadband wireless access continues to...

Ngày tải lên: 21/06/2014, 05:20

... interleaving length at any time, a memory for storing information during interleaving and mappings between information types, operating conditions, and interleaving lengths 314 Quality of Service and ... interleaver, and a bit interleaver, each having a respective interleaving length Also it includes a controller to control which interleavers are active in the interleaving path and thus the aggregate interleaving ... and Resource Allocation in WiMAX Fig 5.2 Architecture of the degrading concealment interleaving system Combining interleaving with encryption and watermark, instead of adding a stand-alone device,...

Ngày tải lên: 21/06/2014, 05:20

... Communications and Networking Dnt ;m for the following reception methods: (1) demodulation without combining, (2) EGC, and (3) MRC Note that the SINR for each combining scenario (i.e., without combining, ... /Nt Note that in MIMO -OFDM systems, the SINR at each subcarrier is an RV parameterized by the frequency offset and channel attenuation In order to derive the average SINR of MIMO -OFDM systems, (22) ... BER as a function of SINR in MIMO -OFDM is derived in this section We consider M-ary square QAM with Gray bit mapping In the work of Rugini and Banelli [11], the BER of SISO -OFDM with frequency...

Ngày tải lên: 21/06/2014, 11:20