Broadband Wireless Access Research Articles

Design of efficient wireless communication system with improved SER using different relay environment

It is very challenging to design an efficient wireless communication system. It is because of many factors, affecting the performance of a typical wireless communication system. With all these years’ rapid development in wireless communication, high demands for broadband mobile wireless communications and the emergence of new wireless multimedia applications have constituted the motivation to the development of broadband wireless access technologies. The long term evolution (LTE) system has been specified by the third generation partnership project (3GPP) on the way towards fourth-generation (4G) mobile to ensure 3GPP keeping the dominance of the cellular communication technologies. LTE-advanced (LTE-A) is the project name of the evolved version of LTE that is being developed by 3GPP. LTE-A will meet or exceed the requirements of the International Telecommunication Union (ITU) for the 4G radio communication standard. LTE-A is being specified initially as part of the 3GPP specifications. Where the current generation of mobile telecommunication networks are collectively known as 3G (for “third generation”), LTE is marketed as 4G. In this paper, LTE-A WINNER MIMO uses orthogonal frequency division multiplexing (OFDM) for the downlink that is, from the base station to the terminal. OFDMA meets the LTE requirement for spectrum flexibility and enables cost-efficient solutions for very wide carriers with high peak rates. The multiple access schemes in LTE downlink uses orthogonal frequency division multiple access (OFDMA). Power saving in transmission is an extensive issue for the multiple access techniques used in LTE, therefore in this paper, an important transmission factor SER for OFDMA system, is considered. This paper provides comparison of SER performance versus SNR of OFDMA system for different relay environment in WINNER, MIMO LTE-A.

Simulation of Memory-Based 1024-Point Fast Fourier Transform for Broadband Wireless Access Technology on FPGA

The limited radio frequency spectrum that can be used for transmission leads to bandwidth and power efficiency being a key requirement in the development of wireless access technology from 3G to 5G today. Data communication technology also requires this as mentioned on high speed network standards such as DSL, WLAN and WMAN with its products ADSL, WiFi and Wimax. In the last few decades we have seen the evolution of the Orthogonal Frequency Division Multiplexing (OFDM) modulation technique used in the technologies mentioned earlier to this day. This technique is regarded as a standard technology for broadband wireless access technology. In hardware implementation, the most preferred by many researchers is the Field Programmable Gate Array chip, as it can be reconfigured. The OFDM technique can be easily implemented because it uses Fast Fourier Transform (FFT) algorithms that are coding and programming capable of reducing the computational time of Discrete Fourier Transform. This paper discusses the implementation of the memory-based 1024-point IFFT / FFT for BWA communications. The design is focused on synthesizing and implementing the system block FFT 1024-point radix-4 using Decimation in Frequency (DIF) method. Implementation for IFFT / FFT 1024-point resource usage slice number 1%, the number of slice flip-flop 1%, the number 4 LUT (Look Up Table) 1%, and the number of IOB 27%. of the FPGA are used.

The Application of Visible Light Communication in Cable Tunnel Patrol

Visible light communication (VLC) using the light emitting diode (LED) will become an appealing alternative to the radio frequency communication technology for indoor wireless broadband access. However, VLC needs a ubiquitous network as its backbone to avoid becoming an information isolated island. Power line communication (PLC) systems could easily solve the informative problem of VLC while powering the LED lamps at the same time, which is considered as a good partner of VLC for the cost-effective implementation. In this paper, a novel and cost-effective framework of ubiquitous indoor broadband access based on deeply integrated VLC and PLC technology with only low-cost modification to the current infrastructure is therefore proposed. The broadband access network supports duplex transmission through each LED using the decode-and-forward (DF) working mode. Furthermore, the VLC-PLC integration technology is applied to typical power grid business scene, which is cable tunnel inspection. During the intelligent inspection, the VLC-PLC system provides voice communication and position service for on-site inspection personnel. The system can ensure the safety and security of power production.

A Joint CAC and Dynamic Bandwidth Allocation Technique for Capacity and QoS Analysis in Heterogeneous LTE based BWA Network: Few Case Studies

Broadband Wireless Access (BWA) network such as LTE brings heterogeneity in terms of different radio access technologies, multi-tier architectures and co-implementation of various protocols to support various types of services with desired Quality of Service (QoS) for the subscribers. However, due to limited bandwidth and high demand of LTE-BWA networks, effective network planning is required to utilize the available radio resources in an efficient way. To achieve this target, this paper aims to implement a unique Radio Resource Management scheme for a heterogeneous LTE based BWA network (BWA Het-Nets) which consists of Small cells along with Macro cells. The proposed analysis has two components: (1) Received Signal Strength (RSS) based CAC policy; and (2) Dynamic Bandwidth Allocation (DBA) scheme for QoS provisioning. The novelty of this work lies on the integration of the RSS based CAC policy with DBA scheme for improved performance in terms of different QoS parameters like New Call Blocking Probability (NCBP), Hand off Call Dropping Probability (HCDP) and Bandwidth Utilization (BU). A Continuous Time Markov Chain based mathematical model is also developed for the realistic analysis of those QoS parameters. The Joint CAC and DBA scheme (JCAC-DBA) in two-tier LTE BWA Het-Nets significantly improves NCBP, HCDP, BU and overall capacity of the network under different combinations of macro/small cells for heterogeneous multimedia services.

The Performance Evaluation of Voip for a Mobile User

Broadband Wireless Access (BWA) technology has developed rapidly and it has dominated the advancement of technology especially in wireless networks. This paper studies the performance evaluation of VoIP for a mobile user and how the QoS parameters vary for different speeds. The purpose of the study is to examine the effect of mobility of a user on the performance of VoIP. In the meanwhile, it is evaluating the simulation and emulation method for its validity to be used for any new upcoming technology. However, the results of the simulation need to be verified and assessed by emulation tested results, hoping that both results match closely with each other.

Compensation of Fading Channels Using Partial Combining Equalizer in MC-CDMA Systems

In this paper the performance of a partial combining equalizer for Multi-Carrier Code Division Multiple Access (MC-CDMA) systems is analytically and numerically evaluated. In the part of channel identification, authors propose a blind algorithm based on Higher Order Cumulants (HOC) for identifying the parameters representing the indoor scenario of Broadband Radio Access Networks (BRAN A) channel model normalized for MC-CDMA systems. Theoretical analysis and numerical simulation results, in noisy environment and for different Signal to Noise Ratio (SNR), are presented to illustrate the performance of the proposed algorithm in the one hand, and the other hand the impact of partial combining equalizer on the performance of MC-CDMA systems.

Performance analysis of filter bank multicarrier system with non‐linear high power amplifiers for 5G wireless networks

The filter bank multicarrier (FBMC) with offset quadrature amplitude modulation (OQAM) is one of the alternative modulation schemes to orthogonal frequency division multiplexing for next generation broadband wireless access systems. The non-linearity of high-power amplifiers (HPA) has a crucial effect on the performance of FBMC systems. In this study, the impacts of non-linear distortion effects are considered in a FBMC-OQAM system when the signal is passed through a HPA for medium- and high-power signals which are modelled as amplitude and phase distortions. Specifically, memory-less HPA non-linear distortion models such as solid-state power amplifier (SSPA), soft-envelope limiter (SEL), travelling wave tube amplifier are proposed for FBMC systems. A closed-form expression for bit error rate expression is derived and analysed for SSPA and SEL models for FBMC/OQAM system with non-linear HPA in frequency-selective Rayleigh channel by varying constellation size in OQAM modulation and input back-off. The performance is compared for the models with 64 sub-channels and input back-off for 6 and 8 dB. In lieu of validating the obtained simulation results, theoretical results are being compared.

Efficient Resource Management for Uplink Scheduling in IEEE 802.16e Standard

The IEEE 802.16e standard, known as mobile Worldwide Interoperability for Microwave Access (WiMAX) becomes the most demanding broadband wireless access (BWA) technology recently. Its main advantage is rapid delivery of services in remote areas due to the cost efficiency factor. The base station (BS) supports data rate up to 70 Mbps, mobile stations with 5–15 km length of coverage, and for the fixed stations the wireless access range up to 50 km. To resolve the bandwidth contention issue and guarantee seamless packet transmission from the subscriber stations (SS) to the BS, the uplink (UL) traffic scheduling must be efficient and reliable. This paper studies the work on the UL scheduling algorithm, namely minimum rest time (MRT). The MRT goal is to strengthen the packet transferring time between the SS and the BS by refining the pre-stipulated expired time and the deadline time of the earliest expiry first (EEF) and earliest deadline first (EDF) hybrid algorithms. These legacy algorithms are inadequate to support the multi-class traffic systems due to the shortage of quality of service (QoS) parameters featuring. Moreover, the algorithms are highly static. Using the Omnet++ with the relevant performance metrics the obtained results confirmed the MRT outperforms effectively from the legacy algorithms.

Performance Analysis of Survivable Hybrid Wireless Optical Broadband Access Networks

The ever increasing needs in internet connectivity leads to the demands for reliable high capacity networks. The future access networks will aimed to satisfy the end user needs through its large bandwidth, higher mobility, best QoS and wide area coverage. Wireless Optical Broadband Access Network (WOBAN) is a compromised solution which has flexible Wireless mesh network as its front end and robust bandwidth efficient Optical network as its back end. If a network element is failed in front end then the traffic will be rerouted in another path and provides reliable unthreaded connectivity. In case of single segment failure all optical network units (ONU)will be disconnected from the Optical line terminal (OLT) results huge data losses. In existing system optimizing backup ONU deployment scheme (OBOF) supports the survivability of WOBAN. The operational efficiency of WOBAN is improved by Automated Failure Deduction and Rerouting Algorithm (AFDRR) during single segment failure based on least congested routes. Implementations of AFDRR is performed in various wireless technologies like WiFi(802.11), WiMAX(802.16) and UMTS. Data packets are send from sender node to the receiver node and QoS parameters like throughput, end to end delay, packet delivery ratio,energy and path switching time are measured.

Design and Realization of Coupled Line Bandpass Filter Using Compact Structure at Frequencies of 3300 MHz – 3400 MHz for WiMAX Application

In this paper, the design of microstrip BPF (Bandpass Filter) for WiMAX (Worldwide Interoperability for Microwave Access) application has been presented. The frequency band allocations for BWA (Broadband Wireless Access) in Indonesia are 2.3; 3.3 and 5.8 GHz. This microtrip BPF is designed using parallel coupled line in compact form and it has spesific parameter, i.e. 3.35 GHz center frequency, 400 MHz bandwidth, VSWR ≤ 2, -3 dB insertion loss and matching impedance between two port is 50 Ω. The Advanced Design System (ADS) software has been used during simulation and optimization. The simulation results show that return loss S11 and insertion loss S21 are -15.31 dB and -2.2 dB at 3.35 GHz respectively. For the design verification, the prototype of the proposed design wasfabricated and measured.The results of the fabrication approach of simulation results, which have return loss value S11and insertion loss S21 of the proposed microstrip filter are -18.20 dB and -2.91 dB at 3.35 GHz respectively. The result shows that the proposed design can be implemented forWiMAX communication system applications

The Cost of Free Spectrum

There has been growing interest in increasing the amount of radio spectrum available for unlicensed broadband wireless access. That includes “prime” spectrum at lower frequencies, which is also suitable for wide area coverage by licensed cellular providers. While additional unlicensed spectrum would allow for market expansion, it could influence competition among providers and increase congestion (interference) among consumers of wireless services. We study the value (social welfare and consumer surplus) obtained by adding unlicensed spectrum to an existing allocation of licensed spectrum among incumbent service providers. We assume a population of customers who choose a provider based on the minimum delivered price, given by the weighted sum of the price of the service and a congestion cost, which depends on the number of subscribers in a band. We consider models in which this weighting is uniform across the customer population and where the weighting is high or low, reflecting different sensitivities to latency. For the models considered, we find that the social welfare depends on the amount of additional unlicensed spectrum, and can actually decrease over a significant range of unlicensed bandwidths. Furthermore, with nonuniform weighting, introducing unlicensed spectrum can also reduce consumer welfare.

Wireless Broadband Access with the Application of IEEE 802.11b based Wi-Fi Model

Wireless Broadband Access with the Application of IEEE 802.11b based Wi-Fi Model

A Comparison Survey of Multiple Access Scheme for upcoming 4G Communication

Ever since wireless broadband communication services were introduced, its demand has been growing constantly. Over the last twenty years, wireless communications have become popular all across the world. It provides an attractive option for many private as well as administrative communication requirements due to various attributes including cost, effectiveness, and agility. The new generation mobile communication systems i.e. fourth generation (4G) are required to support multiple services in various types of environments. 4G is being developed to accommodate the quality of service and essential data rate like wireless broadband access, Multimedia Messaging Service (MMS), video chat, mobile TV. This paper throws light on numerous multiple access techniques anticipated in 4G communication systems. Among all the multiple access (MA) techniques, it is tried to demonstrate that IDMA (Interleave Division Multiple Access) technology can competently alleviate the interference among users and provision high data rates without compromising the quality of service that is required.

Performance Evaluation of Low Density Parity Check (LDPC) Codes Over Gigabit Ethernet Protocol

Error Correcting Low density Parity Check codes enable the communication systems to have a low-power, reliable transmission over noisy channels and can achieve data rates very close to Shannon limit when iteratively decoded. They are used in many digital communication systems such as digital video broadcasting (DVB-S2), MIMO-WLAN (802.11n), WMAN (802.16e), mobile broadband wireless access (MBW A) (802.20) and have a very good error correcting performance over a variety of channels. In this paper we present a performance platform for simulation studies of of LDPC decoding algorithms. We present the results of the simulation studies of Bit Error Rate (BER) performance for various block length like 64 and 256 bytes frame over Additive White Gaussian Noise (AWGN) channel. The comparative studies are made for Log Domain and Log Doman Simple decoding algorithms.

Impairment Analysis of WDM-PON Based on Low-Cost Tunable Lasers

WDM-PON is considered for next-generation broadband backhaul and radio access networking. Among different implementation choices, we propose to utilize low-cost tunable lasers at the remote sites, together with a centralized wavelength locker. Practical implementations require a transparently added downstream signaling channel and upstream per-channel pilot tones for channel tagging and remote wavelength control. Together with some unavoidable crosstalk effects during tuning, all of these system-related items lead to impairments. To keep penalties below 1 dB, the modulation index of the signaling channel must be kept below 15%. Similar values result for the upstream pilot tones. In order to limit crosstalk, such systems require reduced launch power during wavelength tuning and can cover up to 40 km differential reach. These results confirm that WDM-PON based on low-cost lasers is a technically viable approach.

Performance of OFDM-Based WiMAX System Using Cyclic Prefix

The WiMax (Worldwide Interoperability for Microwave Access) is a technology in<strong> </strong>broadband wireless access, which employs OFDM (Orthogonal Frequency Division Multiplexing) as an alternative transmission to enable high speed data in communication system. This research aim is to analyze the performance system of the OFDM-Based WiMAX, which used the cyclic prefix. The model was designed in four schemes of simulation method, the BPSK (Binary Phase Shift Keying, QPSK (Quadrature Phase Shift Keying), 16 QAM (Quadrature Amplitude Modulation) and 64 QAM. Each scheme was investigated BER (Bit Error Rate) on AWGN (Additive White Gaussian Noise) channel and multipath Rayleigh fading channel, which had applied the cyclic prefix. By simulation of the cyclic prefix was produced the modulation measurement of the BPSK, QPSK, 16 and 64 QAM. The performance result of Eb/No 15 dB was obtained the BER of BPSK and QPSK of 1.11E-11, the BER of 16 QAM and 64 QAM of 8.69E-06 and 0.00333 respectively. Those results indicated much smaller BER value than EbNo 0 dB which BPSK and QPSK of 1 BER, 1.5 and 1.75 BER for 16 QAM and 64 QAM respectively. In conclusion, a higher value of EbNo, hence the BER value would be lower.

Performance of OFDM-Based WiMAX System Using Cyclic Prefix

The WiMax (Worldwide Interoperability for Microwave Access) is a technology in<strong> </strong>broadband wireless access, which employs OFDM (Orthogonal Frequency Division Multiplexing) as an alternative transmission to enable high speed data in communication system. This research aim is to analyze the performance system of the OFDM-Based WiMAX, which used the cyclic prefix. The model was designed in four schemes of simulation method, the BPSK (Binary Phase Shift Keying, QPSK (Quadrature Phase Shift Keying), 16 QAM (Quadrature Amplitude Modulation) and 64 QAM. Each scheme was investigated BER (Bit Error Rate) on AWGN (Additive White Gaussian Noise) channel and multipath Rayleigh fading channel, which had applied the cyclic prefix. By simulation of the cyclic prefix was produced the modulation measurement of the BPSK, QPSK, 16 and 64 QAM. The performance result of Eb/No 15 dB was obtained the BER of BPSK and QPSK of 1.11E-11, the BER of 16 QAM and 64 QAM of 8.69E-06 and 0.00333 respectively. Those results indicated much smaller BER value than EbNo 0 dB which BPSK and QPSK of 1 BER, 1.5 and 1.75 BER for 16 QAM and 64 QAM respectively. In conclusion, a higher value of EbNo, hence the BER value would be lower.

Joint Timing Synchronization and Channel Estimation Using Perfect Sequence in Uplink Time Domain Synchronous OFDMA

AbstractTime Domain Synchronous Orthogonal Frequency Division Multiple Access (TDS-OFDMA) is used in mobile broadband wireless access scheme in uplink transmission. This leads to multiple user interference due to timing offset and frequency offset. In this paper, the effect of timing offset and channel estimation in mobile broadband system is analysed. Time-space two dimensional structure is used in TDS-OFDMA and perfect sequence is used for guard interval to achieve perfect timing synchronization and channel estimation for each user. Simulations are performed for timing synchronization and channel estimation using perfect sequence under Urban channel, Indoor Office B channel and HIPER LAN-A channel. Simulation results show that the timing synchronization is achieved and channel estimation performance using perfect sequence is better than CAZAC and PN Sequences.

Taking mHealth Forward: Examining the Core Characteristics.

The emergence of mobile health (mHealth) offers unique and varied opportunities to address some of the most difficult problems of health. Some of the most promising and active efforts of mHealth involve the engagement of mobile phone technology. As this technology has spread and as this technology is still evolving, we begin a conversation about the core characteristics of mHealth relevant to any mobile phone platform. We assert that the relevance of these characteristics to mHealth will endure as the technology advances, so an understanding of these characteristics is essential to the design, implementation, and adoption of mHealth-based solutions. The core characteristics we discuss are (1) the penetration or adoption into populations, (2) the availability and form of apps, (3) the availability and form of wireless broadband access to the Internet, and (4) the tethering of the device to individuals. These collectively act to both enable and constrain the provision of population health in general, as well as personalized and precision individual health in particular.

A heuristic design for the uplink scheduling in LTE-A networks

Long Term Evolution advanced (LTE-A) is recognized as the main technology towards the broadband wireless access for emerging network services. In LTE, single carrier frequency division multiple access (SC-FDMA) is applied as the transmission technology for uplink traffic. This paper proposes a novel scheme to schedule the uplink traffic of both LTE and LTE-A UE in LTE-A network environment. The proposed scheme considers the localized subcarrier by properly using the Gale-Sharply concept, quality of services (QoS), and the selection of component carriers (CC) for LTE-A UE. The simulation results show that the proposed scheme can effectively schedule radio resource to UE according to their types and desired QoS.