CiteULike: dcastro's 80216

Design and analysis of an IEEE 802.16e-based OFDMA communication system

Krishna Balachandran — 2008-06-04T12:25:17-00:00

Bell Labs Technical Journal, Vol. 11, No. 4. (2007)

IEEE 802.16e has emerged as a strong candidate standard for future wireless systems primarily because it offers the potential for high spectral efficiency, flexible spectrum options (e.g., 2-6 GHz), scalable carrier bandwidth options (e.g., from 1.25 MHz to 20 MHz), multiple duplexing options (time and frequency division duplex), various subchannelization options, and, unlike its IEEE 802.16 predecessors, mobility. Because of the recent emergence of IEEE 802.16e and the complexity it poses in system analysis, there is little published work in the literature regarding the actual system capacity/ throughput performance of IEEE 802.16e for high data rate services. In this paper, we investigate the link and system level performance on the downlink of an IEEE 802.16e-based orthogonal frequency division multiple access (OFDMA) communication system and provide recommendations on high performance IEEE 802.16e system design and deployment configurations. We also propose dynamic resource allocation methods that may be used in OFDMA systems and investigate their performance. @ 2007 Alcatel-Lucent.

Scalable OFDMA Physical Layer in IEEE 802.16 WirelessMAN

Hassan Yaghoobi — 2008-01-10T13:40:13-00:00

The concept of scalability was introduced to the IEEE 802.16 WirelessMAN Orthogonal Frequency Division Multiplexing Access (OFDMA) mode by the 802.16 Task Group e (TGe). A scalable physical layer enables standard-based solutions to deliver optimum performance in channel bandwidths ranging from 1.25 MHz to 20 MHz with fixed subcarrier spacing for both fixed and portable/mobile usage models, while keeping the product cost low. The architecture is based on a scalable subchannelization structure...

A Distributed Approach to Interference Mitigation Between OFDM-Based 802.16 Systems Operating in License-Exempt Spectrum

O Ashagi — 2008-02-25T18:14:17-00:00

Communications, 2007. ICC '07. IEEE International Conference on (2007), pp. 4855-4860.

System capacity in OFDMA-based WiMAX

C Tarhini — 2008-01-30T14:07:43-00:00

Systems and Networks Communications, 2006. ICSNC '06. International Conference on (2006), pp. 70-70.

In this paper, we study the capacity of broadband wireless OFDMA-based WiMAX systems, in the presence of both constant-bit-rate streaming traffic as well as elastic one, under a dynamic configuration wherein users come to the system and leave it after a finite duration. This duration is function of the resources they obtain for the case of elastic flows; it is not for voice ones. Using Markovian analysis, we calculate several performance measures, such as the blocking probability and mean transfer time, using exact and approximate, quasi-stationary-based, solutions. We eventually show numerically the performance of such a system under different admission figures.

Multi-Cell Slots Allocation in OFDMA Systems

David Amzallag — 2008-01-11T08:39:20-00:00

Mobile and Wireless Communications Summit, 2007. 16th IST (2007), pp. 1-5.

OFDMA (Orthogonal Frequency Division Multiple Access) is considered to be the leading technology for the upcoming 4G cellular infrastructure. OFDMA is a multi-user version of the popular OFDM (Orthogonal Frequency Division Multiplexing) digital modulation scheme. Multiple access is achieved in OFDMA by assigning subsets of subcarriers (subchannels or slots) to individual users. This allows for multiple simultaneous low data rate transmissions to several users. In this paper we describe several optimization problems related to the allocation of radio resources in OFDMA systems. The basic problem we define is a slots assignment task in a multi-cell OFDMA environment. The goal is to assign subchannels to mobile stations such that the demands of all of mobile stations will be satisfied with minimum interferences. We then describe two further optimization problems that generalize the slots assignment problem. A close to optimal solution to these problems will allow providers to better utilize their radio resources and to provide services in a cost efficient way.

Mobility support for IEEE 802.1.6d wireless networks

KK Leung — 2008-01-08T11:11:51-00:00

Wireless Communications and Networking Conference, 2005 IEEE, Vol. 3 (2005), pp. 1446-1452 Vol. 3.

We study in this paper whether mobility can be supported by the 802.16d network without any change in the specification. Mobility capability involves two main issues: connection handoff and correct reception for moving terminals. We find that seamless connection handoff can be achieved within the 802.16d standard by: 1) applying some of the existing functionalities defined for the terminal initialization process; 2) devising a set of protocols for message exchanges for handoff; and 3) forwarding some of the operational parameters from the current base station to a new one via the backhaul network, instead of over the radio link. As for reception at moving terminals, our analysis of bit error rate for the OFDMA mode shows that, under typical radio conditions, the link can provide satisfactory error performance for terminal speed up to tens of kph. As a result, we show that the current 802.16d standard with our proposed technique can support user mobility.

Protocol and control mechanisms to save terminal energy in IEEE 802.16 networks

S Mukherjee — 2007-12-07T10:23:59-00:00

Communications, Computers and signal Processing, 2005. PACRIM. 2005 IEEE Pacific Rim Conference on (2005), pp. 5-8.

The IEEE 802.16-2004 standard (formerly 802.16d) has been approved to provide last-mile connectivity to fixed locations by radio links. Although the IEEE committee is working on a future 802.16e standard to support terminal mobility, we believe that adding mobility support to the present standard will offer a significant business opportunity for service providers by enabling them to serve a large pool of potential users whose laptops and PDAs are 802.16-2004 enabled. In our prior work, we have shown how to reuse commands from the 802.16-2004 standard to support handoff between access points without any change to the standard. However, given that the mobile terminals will be severely constrained by battery life, it is essential that new protocols and control mechanisms be devised to save terminal energy, based on the existing 802.16-2004 standard. To achieve this objective, in the present paper we propose protocols and use existing 802.16-2004 commands to put mobile terminals to "sleep" (to save energy) when they are idle, and "wake them up" when there is traffic destined for them. We also demonstrate how this "sleep/wakeup" cycle can is compatible with the handoff process.

IEEE 802.16 based last mile broadband wireless military networks with quality of service support

K Wongthavarawat — 2007-12-07T10:17:32-00:00

Military Communications Conference, 2003. MILCOM 2003. IEEE, Vol. 2 (2003), pp. 779-784 Vol.2.

Future Department of defense warfighting concepts leverage information superiority and will require vast improvements in information transfer in terms of higher bandwidth, Quality of Service (QoS) support and connection to a high speed backbone. The new IEEE 802.16 broadband wireless access system is a viable alternative that can meet such requirements. In addition, this network can be swiftly deployed to interconnect the military theater, emergency response, and disaster relief operations to the backbone. Due to the diverse multimedia traffic with different priorities and QoS requirements, it is a well know fact that it is imperative to provide QoS support in military networks. However, the IEEE 802.16 provides only signaling mechanisms, but does not specify any scheduling or admission control algorithms that ultimately provide QoS support. In this paper we introduce a new scheduling algorithm for IEEE 802.16 broadband wireless access standard. The proposed solution which is practical and compatible to the IEEE 802.16 standard, provides QoS support to different traffic classes. To the best of our knowledge this is the first such algorithm. The simulation studies show that the proposed solution includes QoS support for all types of traffic classes as defined by the standard. We have shown the relationship between traffic characteristics and its QoS requirements and the network performance. This study will help network architects to decide the system parameters as well as the kind of traffic characteristics for which the network can provide QoS support.

Enhanced power efficient sleep mode operation for IEEE 802.16e based WiMAX

Shengqing Zhu — 2007-12-07T10:14:11-00:00

Mobile WiMAX Symposium, 2007. IEEE (2007), pp. 43-47.

To support battery powered mobile broadband wireless access devices efficiently, IEEE 802.16e defines a sleep mode operation for conserving the power of mobile terminals. In this paper we analyze the power consumption and the mean delay of IEEE 802.16e sleep mode operation with a theoretical Markov chain model. The analytical results show that there is a tradeoff between the power consumption and the mean delay, and the key of the tradeoff is the initial sleep window. Then, we present a heuristic algorithm to tune the initial sleep window dynamically according to the traffic load. Extensive simulation results show that the proposed algorithm can improve the power consumption up to 30% compared to the IEEE 802.16e standard. The price is just little increase of the mean delay. Therefore, the proposed algorithm provides a proper tradeoff between the power consumption and the mean delay

Energy saving mechanism in the IEEE 802.16e wireless MAN

Y Xiao — 2007-12-07T09:56:18-00:00

Communications Letters, IEEE, Vol. 9, No. 7. (2005), pp. 595-597.

In this paper, we study energy consumption for the IEEE 802.16e broadband wireless access (BWA) network, A mobile subscriber station goes to sleep-mode after negations with the base station and temporarily wake-up periodically for a short interval to check whether there is downlink traffic to it to decide whether it goes to wake-mode or continues to be in the sleep-mode. The sleep interval is increased exponentially upon no arrival traffic. We analytically model the sleep-mode scheme and validate the model with simulations.

Broadband wireless access solutions based on OFDM access in IEEE 802.16

I Koffman — 2007-12-07T09:54:03-00:00

Communications Magazine, IEEE, Vol. 40, No. 4. (2002), pp. 96-103.

Broadband wireless access is the most challenging segment of the wireless revolution since it has to demonstrate a viable alternative to the cable modem and DSL technologies that are strongly entrenched in the last mile access environment. The Analysis, Research, and Consultancy (ARC) Group forecasts that the fixed wireless deployments in both homes and businesses will reach almost 28 million by 2005, with North America and Western Europe accounting for 24 percent and 27 percent of these, respectively. Whether the promise of BWA will materialize depends on its appeal to telecom operators from the perspective of deployment economics, where the critical factor is the ease of installation of broadband wireless subscriber units. This ultimately leads to nonprofessional installation of integrated all-indoor BWSUs. Consequently the physical layer (PHY) has to mitigate the very tough impairments that characterize these non-line-of-sight environments. In this context we overview the work of the one of the IEEE 802.16 standard subcommittee projects that deals with a BWA solution based on OFDM access (OFDMA) aiming at the most challenging NLOS scenarios

Planning of an IEEE 802.16e Network for Emergency and Safety Services

Fernando Velez — 2007-12-06T17:05:37-00:00

3G and Beyond, 2005 6th IEE International Conference on (2005), pp. 1-5.

An overlaid Wimax cellular structure is proposed for emergency and safety services, with micro-cells covering urban hotspots over a macro-cellular structure. In the region of Beira Interior the process of cellular planning has to account for carrier-to-noise-interference ratio. Sectorisation is used in order to reduce reuse patterns and increase system capacity, while cell overlay is proposed to overcome coverage problems in large towns and cities. Geographic Information Systems tools are considered for Line-of-Sight discovery, and ~75% of LoS coverage is guaranteed in the city of Covilhã. The point-to-point component is also being incorporated in the planning tool. By comparing the 3.5GHz and the 5.8GHz bands one concludes that it is possible to use lower values of the antenna gains in the first case.

Fixed broadband wireless access: state of the art, challenges, and future directions

H Bolcskel — 2007-12-06T17:04:35-00:00

Communications Magazine, IEEE, Vol. 39, No. 1. (2001), pp. 100-108.

This article provides an overview of fixed broadband wireless access technology. Focusing on the band below 3 GHz, we describe BWA service and carrier needs, deployment scenarios, architectural requirements, physical layer, medium access control, and radio link protocol requirements. We characterize fixed BWA channels, outline the major challenges of fixed BWA, and study requirements for future BWA systems. Finally, we show that the use of multiple antennas at both ends of a fixed wireless link provides significant leverages

Adaptive Power Saving Strategies for IEEE 802.16e Mobile Broadband Wireless Access

Jaehyuk Jang — 2007-12-06T16:57:47-00:00

Communications, 2006. APCC '06. Asia-Pacific Conference on (2006), pp. 1-5.

IEEE 802.16e is an emerging standard for mobile wireless broadband access systems. In any mobile networks, power saving is one of the most important features for the extension of devices' lifetime. In this paper, we introduce the sleep-mode operation of IEEE 802.16e and parameters related to this operation. Then, we adapt these parameters according to different traffic types for efficient power saving. For CBR traffic, by setting a proper initial-sleep window size, the maximum delay can be guaranteed while saving the average power consumption. For FTP traffic, by sleeping during queue-empty periods, the throughput performance is barely sacrificed while efficient power saving is accomplished

On the Performance of IEEE 802.16 OFDMA System Under Different Frequency Reuse and Subcarrier Permutation Patterns

H Jia — 2007-12-06T16:50:46-00:00

Communications, 2007. ICC '07. IEEE International Conference on (2007), pp. 5720-5725.

Performance analysis of the IEEE 802.16 wireless metropolitan area network

Dong-Hoon Cho — 2006-07-24T14:33:38-00:00

Distributed Frameworks for Multimedia Applications, 2005. DFMA '05. First International Conference on (2005), pp. 130-136.

In this paper, we propose a new QoS architecture for the IEEE 802.16a MAC protocol and present a bandwidth allocation and admission control policy for the architecture. Our architecture provides QoS support to real-time traffic with high priority while maintaining throughput performance to an acceptable level for low priority traffic. Analytical and simulation results assure advantages of our architecture.

A dual-band 4.9-5.95 GHz, 2.3-2.5 GHz, 0.18 /spl mu/m CMOS transceiver for 802.11 a/b/g-802.16d/e

I Vassiliou — 2006-07-24T16:24:44-00:00

Radio and Wireless Symposium, 2006 IEEE (2006), pp. 31-34.

A zero-IF, 4.9-5.95 GHz, 2.3-2.5 GHz, transceiver is fabricated on a 0.18 /spl mu/m CMOS process. By using a fractional-N synthesizer, an integrated phase error of 0.6/spl deg/ (0.7/spl deg/) at 5 GHz (2.4 GHz) is achieved, while supporting fine frequency resolution. Digital calibration eliminates I/Q mismatch and achieves accurately matched baseband filters. The transceiver is compliant to 802.11a/b/g, while programmable bandwidth filters and an EVM of -35 dB in both transmit and receive, make it suitable for applications based on 802.16d/e.

Interference-Aware IEEE 802.16 WiMax Mesh Networks

Hung-Yu Wei — 2006-01-05T15:44:35-00:00

Vehicular Technology Conference, 2005. VTC 2005-Spring. 2005 IEEE 61st, Vol. 5 (2005), pp. 3102-3106.

The IEEE 802.16 WiMax standard provides a mechanism for creating multi-hop mesh, which can be deployed as a high speed wide-area wireless network. To realize the full potential of such high-speed IEEE 802.16 mesh networks, two efficient wireless radio resource allocation extensions were developed. The objective of this paper is to propose an efficient approach for increasing the utilization of WiMax mesh through appropriate design of multi-hop routing and scheduling. As multiple-access interference is a major limiting factor for wireless communication systems, we adopt here an interference-aware cross-layer design to increase the throughput of the wireless mesh network. In particular, our scheme creates a tree-based routing framework, which along with scheduling is interference aware and results in a much higher spectral efficiency. Performance evaluation results show that the proposed interference-aware scheme achieves significant throughput enhancement over the basic IEEE 802.16 mesh network.

IEEE 802.16 broadband wireless technology and its application to the military problem space

JL Burbank — 2007-01-05T12:19:22-00:00

Military Communications Conference, 2005. MILCOM 2005. IEEE (2005), pp. 1905-1911 Vol. 3.

This paper discusses the emerging IEEE 802.16 broadband wireless technologies and potential applicability to military networks. Interest continues to grow in the military network design community, for leveraging commercial technologies for use in the global information grid (GIG). This is also true in the design of tactical edge networks where there is growing interest in leveraging commercial wireless networking technologies such as the IEEE 802.11 wireless local area network (WLAN) technology family. An emerging commercial capability is in the area of wireless metropolitan area networks (WMA Ns). The emerging IEEE 802.16 broadband wireless access standards aim to provide high data rates over wide geographic ranges. There is also ongoing standardization effort of the eventual IEEE 802.20 mobile broadband wireless solution. This paper provides an overview of IEEE 802.16, then presents a high-level military applicability analysis, identify any technical deficiencies that may require military-specific enhancements. This analysis focuses on the areas of achievable coverage, supportable mobility, quality-of-service (QoS), and security.

Energy management in the IEEE 802.16e MAC

Y Zhang — 2006-12-07T16:33:53-00:00

Communications Letters, IEEE, Vol. 10, No. 4. (2006), pp. 311-313.

Energy management is an important component for the emerging standard IEEE 802.16e supporting mobility. In this paper, we characterize the standardized sleep mode in IEEE 802.16e. The comparison between our result and the simulation shows that our analytical model is accurate in evaluating the energy consumption and hence provides a potential guidance in efficiently managing energy.

Analysis of the Statistical Properties of the SINR in the IEEE 802.16 OFDMA Network

SN Moiseev — 2007-01-05T13:38:36-00:00

Communications, 2006 IEEE International Conference on, Vol. 12 (2006), pp. 5595-5599.

In the IEEE 802.16 network the SINR per subcarrier, the average SINR, and the SINR RMS are stochastic processes. In this paper, we analyze the statistical properties of these stochastic processes using system level simulation. We present the probability density functions for the SINR per subcarrier and the average SINR stochastic processes expressed in both logarithmic and linear scales. We also present the probability density function for the SINR RMS stochastic process, expressed in the logarithmic scale. The results, obtained in this paper, allow using the statistical approach while developing the adaptive transmission algorithms for the IEEE 802.16 network.

MAC performance of IEEE 802.16e

AE Xhafa — 2007-11-30T11:38:07-00:00

Vehicular Technology Conference, 2005. VTC-2005-Fall. 2005 IEEE 62nd, Vol. 1 (2005), pp. 685-689.

A new ranging method for OFDMA systems

Hlaing Minn — 2006-08-16T13:49:07-00:00

Global Telecommunications Conference, 2005. GLOBECOM '05. IEEE, Vol. 3 (2005), pp. 1435-1440.

We present a new initial ranging method for OFDMA systems such as IEEE 802.16a. First, a new orthogonal ranging signal design is proposed by which an efficient, low-complexity multi-user ranging signal detection is developed. Based on the ranging signal detector results, power estimation for the detected ranging subscriber stations is performed. Then, by utilizing the proposed orthogonal ranging signal design together with the redundancy introduced by cyclic prefixes, a new iterative multi-user timing offset estimator is presented. Compared with the existing methods utilizing the CDMA-type ranging codes (in frequency-domain) defined in IEEE 802.16a, the proposed method achieves a better performance and greater robustness against multi-user interference and multi-path fading channels.

Design and implementation of a simulator based on a cross-layer protocol between MAC and PHY layers in a WiBro compatible IEEE 802.16e OFDMA system

Taesoo Kwon — 2006-01-05T15:44:55-00:00

Communications Magazine, IEEE, Vol. 43, No. 12. (2005), pp. 136-146.

Broadband wireless access with WiMax/802.16: current performance benchmarks and future potential

A Ghosh — 2006-06-30T20:09:07-00:00

Communications Magazine, IEEE, Vol. 43, No. 2. (2005), pp. 129-136.

The IEEE 802.16 family of standards and its associated industry consortium, WiMax, promise to deliver high data rates over large areas to a large number of users in the near future. This exciting addition to current broadband options such as DSL, cable, and WiFi promises to rapidly provide broadband access to locations in the world's rural and developing areas where broadband is currently unavailable, as well as competing for urban market share. WiMax's competitiveness in the marketplace largely depends on the actual data rates and ranges that are achieved, but this has been difficult to judge due to the large number of possible options and competing marketing claims. This article first provides a tutorial overview of 802.16. Then, based on extensive recent studies, this article presents the realistic attainable throughput and performance of expected WiMax compatible systems based on the 802.16d standard approved in June 2004 (now named 802.16-2004). We also suggest future enhancements to the standard that could at least quadruple the achievable data rate, while also increasing the robustness and coverage, with only moderate complexity increases.

A survey on emerging broadband wireless access technologies

Mehmet Kuran — 2007-09-11T08:56:29-00:00

Computer Networks, Vol. 51, No. 11. (8 August 2007), pp. 3013-3046.

Wireless broadband technologies provide ubiquitous broadband access to wireless users, enabling services that were available only to wireline users. In this paper, we summarize emerging wireless broadband access technologies, ranging from WLANs to satellite communications. We explain the latest standards in the IEEE 802.11 and IEEE 802.16 families in detail. The MAC layer mechanisms of IEEE 802.11e, 802.11n, and 802.11s standards are explained as well as the point-to-multipoint and Mesh modes of IEEE 802.16. The recent mobility amendment to the WiMAX family, IEEE 802.16e, is also described. Though the earliest versions of some of these technologies date back to 1996 (such as IEEE 802.11) and some are obsolete (such as HiperLAN), they have been included in this survey for the sake of completeness. Wireless technologies can be categorized based on their coverage areas. IEEE 802.11 and ETSI HiperLAN standards are considered for wireless access in local areas. IEEE 802.16 and 802.22, ETSI HiperACCESS and HiperMAN, WiBro, and HAP technologies can be used to provide service in metropolitan areas. Lastly, IEEE 802.20 and satellite systems provide service as wide area networks. Since the aim of this survey is to summarize wireless broadband technologies for data services, technologies such as Wireless USB are excluded. 3G and 4G systems have also been excluded since they are covered in detail in [C. Smith, D. Collins, 3G Wireless Networks, second ed., McGraw-Hill Osborne Media, 2006; S.G. Glisic, Advanced Wireless Networks: 4G Technologies, Wiley Publishing, 2005].

Multihop Relaying for Broadband Wireless Mesh Networks: From Theory to Practice

O Oyman — 2007-11-15T11:46:51-00:00

Communications Magazine, IEEE, Vol. 45, No. 11. (2007), pp. 116-122.

IEEE standard 802.16: a technical overview of the WirelessMAN<sup>TM</sup> air interface for broadband wireless access

C Eklund — 2006-07-24T13:30:50-00:00

Communications Magazine, IEEE, Vol. 40, No. 6. (2002), pp. 98-107.

The broadband wireless access industry, which provides high-rate network connections to stationary sites, has matured to the point at which it now has a standard for second-generation wireless metropolitan area networks. The IEEE standard 802.16, with its WirelessMAN<sup>TM </sup> air interface, sets the stage for widespread and effective deployments worldwide. This article overviews the technical medium access control and physical layer features of this new standard

Performance analysis of an efficient packet-based IEEE 802.16 MAC supporting adaptive modulation and coding

M Settembre — 2007-01-02T00:28:08-00:00

Computer Networks, 2006 International Symposium on (2006), pp. 11-16.

The challenge for broadband fixed wireless access (BFWA) systems, which represent an attractive solution for broadband access in the last mile and for wireless backhauling applications in the "middle mile", lies in providing high data rates and quality of service (QoS). Such requirements mainly derive from the need to provide new bandwidth consuming multimedia services and applications, efficient handling of IP traffic, effective use of the limited radio spectrum and a greater backhaul capacity to support the increased number of users per cell site. IEEE 802.16 family of standards and its associated consortium WiMAX are gaining more and more interest in the telecommunication areas as broadband fixed wireless access solution with possible extension in nomadic and mobile area. Its main leverages are an efficient handling of IP traffic, the support of channel adaptivity and advanced QoS management. This paper aims at defining a new packet-based scheduling strategy for an IEEE 802.16 system supporting variable length MAC protocol data units (PDUs) and adaptive coding and modulation while fulfilling QoS requirements. A performance analysis of the proposed scheduler is presented and discussed in terms of packet transfer delay, MAC overhead and average throughput.

Performance analysis of OFDM in frequency selective time-variant channels with application to IEEE 802.16 broadband wireless access

M Al-Gharabally — 2007-01-05T12:17:45-00:00

Military Communications Conference, 2005. MILCOM 2005. IEEE (2005), pp. 351-356 Vol. 1.

In this paper, the performance of orthogonal frequency division multiplexing systems in frequency selective and time-variant Rayleigh fading channels is analyzed. Channel variations severely degrade the performance of OFDM by introducing both a complicated multiplicative distortion and an additive intercarrier interference. The IEEE 802.16 standard is designed to provide broadband wireless-services for fixed and pedestrian terminals, and hence, the channel is assumed to be slowly variant during one OFDM symbol. Under this assumption, the multiplicative distortion can be simplified as a sum of two correlated Rayleigh random variables. Based on this simplification, and by observing that the signal-to-interference-plus-noise ratio of the OFDM system is similar to the expression of the signal-to-noise ratio at the output of an equal gain combiner, we derive a closed form analytical expression for the symbol error rate. The proposed analytical expression is verified through numerical evaluation using the parameters of the IEEE 802.16 standard.

An efficient timing synchronization scheme for OFDM systems in IEEE 802.16d

Jie-Ping Xu — 2007-01-05T12:20:36-00:00

Microwave Conference Proceedings, 2005. APMC 2005. Asia-Pacific Conference Proceedings, Vol. 1 (2005), 3 pp..

This paper presents an efficient symbol timing synchronization algorithm for an orthogonal frequency division multiplexing (OFDM) system that is adapted to IEEE 802.16d standard. This efficient algorithm is based on the preamble structure defined in IEEE 802.16d. The preamble's symmetrical structure is exploited to reduce computational complexity. The useful signal can be distinguished from others according to the receipt of the long preamble, and the beginning of the signals can be found. The results of simulation show that the timing will be more accurate at very low signal-to-noise ratios.

IEEE 802.16e system performance: analysis and simulations

F Wang — 2006-12-07T16:35:48-00:00

Personal, Indoor and Mobile Radio Communications, 2005. PIMRC 2005. IEEE 16th International Symposium on, Vol. 2 (2005), pp. 900-904 Vol. 2.

In this paper, the performance of a prototypical IEEE 802.16e network is analyzed via link and system simulations. The exponential effective SIR mapping (EESM) is used to map the instantaneous SINR of received signals to a service-specific packet erasure rate (PER), which is in turn used to assess the downlink and uplink network and user data throughput. A variety of data traffic models are considered, including web browsing (HTTP) and full buffer sessions, operating in flat-fading and frequency-selective multipath channels such as the ITU Pedestrian-B model. The downlink network performance of the prototypical IEEE 802.16e network is compared to a 3GPP UMTS high speed downlink packet access (HSDPA) system of similar physical dimensions. System simulation results for the prototypical IEEE 802.16e network considered show-when frequency-selective scheduling is not applied-that the IEEE 802.16e downlink has similar throughput performance as HSDPA for a 70/30 TDD DL/UL frame split but approximately 40%-50% higher spectral efficiency, although control channel overhead and uplink capacity limitation remain significant open issues for further study.