ofdm

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ASIC Implementation of Autocorrelation and CORDIC Algorithm for OFDM Based WLAN

This paper deals with design and implementation of Autocorrelator and CORDIC algorithm for OFDM based WLAN on ASIC. The architectures of both Autocorrelator and CORDIC are processed through ASIC Design flow to check for the timing of both setup as well as hold time for 130nm technology. Autocorrelator is designed...

Tags: Algorithm, WLAN, Autocorrelator, Matlab Simulation, ASICs, OFDM, Wireless LANs, LANs, Semiconductors, Hardware, Wireless And Mobility, Networking

White papers 2009-02-28

Multi-User Adaptive Resource Allocation Scheme for WLAN OFDM-MIMO Transmission

Orthogonal Frequency Division Multiplexing OFDM has recently been proposed for use in high data-rate wireless systems. OFDM has an important property of spectrum utilization technique that distributes each tone, which is orthogonal with every other tone. The system capacity can be significantly improved by multiple transmit and receive antennas that...

Tags: WLAN, MIMO, Allocation, Wireless, PSG College Of Technology, OFDM, Wireless LANs, LANs, Wi-Fi, Wireless And Mobility, Networking

White papers 2008-08-25

Digital Automatic Gain Control Integrated on WLAN Platform

This paper presents a solution for DAGC Digital Automatic Gain Control in WLAN receivers compatible to IEEE 802.11a/g standard. Those standards define communication in 5/2.4 GHz band using Orthogonal Frequency Division Multiplexing OFDM modulation scheme. WLAN Transceiver that the author has used enables gain control over Low Noise Amplifier LNA...

Tags: WLAN, Wireless LANs, LANs, Wi-Fi, OFDM, Wireless And Mobility, Networking

White papers 2008-07-01

Techno-Economic Case for a Remote WiMAX Cell

Problem of providing reliable and economically sustainable modern digital telecommunications services in remote rural areas is not new, and using Fixed Wireless Access FWA systems had been previously suggested as being one of the most appropriate solutions to resolving this problem. After certain decline, the revival of FWA technology had...

Tags: OFDM Technology, OFDM, WiMAX, Wireless And Mobility

White papers 2008-05-08

RF Transceiver of WiMAX Base Station for 802.16d

The design of a RF transceiver for WiMAX base station based on IEEE 802.16d standard using OFDM technology is presented in this paper. The RF transceiver operates in 700MHz frequency band, and employs dual-conversion configuration and FDD mode. The experimental results show that the RF transceiver has perfect performance for...

Tags: IEEE, RF Transceiver, WiMAX, Wi-Fi, OFDM, Wireless And Mobility

White papers 2008-04-08

Effects of Fixed Point FFT on the Performance of OFDM in Wireless LAN

This paper analyzes the effects of fixed point Fast Fourier Transform FFT computation in Orthogonal Frequency Division Multiplexing OFDM for Wireless Local Area Network WLAN application. The performance of WLAN has been investigated using Matlab simulations under Additive White Gaussian Noise AWGN channel for different modulation schemes. The simulations carried...

Tags: Performance, WLAN, Wireless, LANs, OFDM, Wireless LANs, Wi-Fi, Wireless And Mobility, Network Technology, Networking

White papers 2008-02-22

Experimental Evaluation of Adaptive Modulation and Coding in MIMO WiMAX With Limited Feedback

This paper evaluates the throughput performance of an OFDM WiMAX (IEEE 802.16-2004, Section 8.3) transmission system with Adaptive Modulation and Coding AMC by outdoor measurements. The standard compliant AMC utilizes a 3-bit feedback for SISO and Alamouti coded MIMO transmissions. By applying a 6-bit feedback and spatial multiplexing with individual...

Tags: Measurement, MIMO, Transmission, Hindawi Publishing, AMC, Performance Management, OFDM, WiMAX, Wireless And Mobility, Human Resources, Workforce Management

White papers 2007-11-28

From WiFi to WiMAX: Techniques for High-Level IP Reuse Across Different OFDM Protocols

Orthogonal Frequency-Division Multiplexing OFDM has become the preferred modulation scheme for both broadband and high bitrate digital wireless protocols because of its spectral efficiency and robustness against multipath interference. Although the components and overall structure of different OFDM protocols are functionally similar, the characteristics of the environment for which a...

Tags: Technique, WiMAX, Wi-Fi, Wireless, Wireless Protocol, OFDM, Wireless And Mobility

White papers 2007-11-05

Performance Analysis of Multiantenna WiMAX Systems Over Frequency-Selective Fading Channels

A multicell WiMax system which supports Orthogonal Frequency Division Multiplexing OFDM and antenna arrays at the base stations is considered in this paper as conforming to the IEEE 802.16-2004 standard. Focusing on the uplink, the paper proposes an analytical framework to assess the average error probability of the system over...

Tags: Performance, IEEE, IEEE 802.16, WiMAX, OFDM, Wireless And Mobility, Wi-Fi

White papers 2007-06-08

System-Level Model for OFDM WiMAX Transceiver in Radiation Environment

WiMAX Worldwide Interoperability for Microwave Access, an evolving standard for point-to-multipoint wireless networking, works for the "last mile" connections for replacing optical fiber technology network but with no need for adding more infra structure within crowded areas. Optical fiber technology is seriously considered for communication and monitoring applications in space...

Tags: Environment, Optical Fiber, Alexandria University, Optical Fiber Technology, OFDM, WiMAX, Fiber Optics, Optical Networking, Network Technology, Wi-Fi, Wireless And Mobility, Telecommunications, Networking

White papers 2007-04-26

A Broadband Underwater Acoustic Modem Implementation Using Coherent OFDM

Multicarrier modulation in the form of Orthogonal Frequency Division Multiplexing OFDM has prevailed in recent broadband wireless systems over radio channels. In the senior design project discussed in this paper, the authors have implemented an acoustic OFDM modem that transmits digital data through sound propagation. This paper demonstrates OFDM transmission...

Tags: Broadband, University Of Connecticut, OFDM, Modems, Broadband Internet, Telecommunications, Wireless, Hardware, Components

White papers 2007-02-26

Microsoft to launch iPhone rival?

Microsoft to launch iPhone rival?Taking the long view?True, WiMAX hasn't hit it's stride yet but given time I see it being everywhere. Especially once the "mesh" parts get hammered out.Oh god A cell phione that crahesGreat look like microsoft is going to try to ruin the cellular telephine market...

Tags: Telecom & Utilities, Wireless LANs, Microsoft Windows Mobile, phone, Microsoft Corp., Apple iPhone, OFDM

Discussion threads 2007-02-09

Microsoft to launch iPhone rival?

Crunch Gear is reporting that it has confirmed rumors of a Microsoft Zune Phone. Would that be a zPhone? According to Crunch Gears Matt Hickey whose hook was a Microsoft filing with the FCC all cell phone manufacturers must register their devices with the FCC:....it looks like MS is working...

Tags: Crunch Gears Matt Hickey, Entertainment, General, Hollywood On Demand, Microsoft Zune, Mobile, Personal Technology, telephone, Telephony, WiMAX, Wired &, Wireless, Zune Phone

Blog posts 2007-02-09

Joint Compensation of Transmitter and Receiver Impairments in OFDM Systems

The implementation of OFDM-based systems suffers from impairments such as in-phase and quadrature-phase IQ imbalances in the front-end analog processing. Such imbalances are caused by the analog processing of the Radio Frequency RF signal and can be present at both the transmitter and receiver. The resulting IQ distortion limits the...

Tags: Compensation, Transmitter, Imbalance, OFDM, Wireless

White papers 2007-01-01

Joint Congestion Control and OFDMA Scheduling for Hybrid Wireline-Wireless Networks

This paper considers joint congestion control and multiuser scheduling in a hybrid wireline and wireless network, where the air interface of wireless links is based on Orthogonal Frequency Division Multiplexing OFDM. For static channels, the paper formulates this cross-layer design as a Network Utility Maximization NUM problem with both wireline...

Tags: Congestion Control, Wireless Link, University Of Minnesota, OFDMA, OFDM, Wi-Fi, Wireless

White papers 2006-12-13

Low-Complexity Time-Domain ICI Equalization for OFDM Communications Over Rapidly Varying Channels

This paper considers wireless OFDM communications over rapidly varying channels as occurring e.g. in high-mobility scenarios. Here, InterCarrier Interference ICI is the major source of impairment that limits the transmission quality. This paper proposes novel equalizers to combat ICI and enable reliable communications even at high Doppler frequencies. In contrast...

Tags: Channel, Vienna University, OFDM, Wireless

White papers 2006-11-28

Will Aussie patents turn Wi-Fi into a house of cards?

Will Aussie patents turn Wi-Fi into a house of cards?WiMax uses OFDMAWiMax also uses Orthogonal Frequency Division Multiple Access technologyhttp://www.intel.com/netcomms/technologies/wimax/OFDMA and OFDMMobile WiMax (802.16-2005)'s OFDMA has a fair amount in common with OFDM, in terms of subdividing frequencies ranges into subchannels, each of which can carry independent data stream. With...

Tags: government, Wi-Fi, OFDMA, OFDM

Discussion threads 2006-11-21

Joint Compensation of IQ Imbalance and Phase Noise in OFDM Systems

The joint effects of IQ imbalance and phase noise on OFDM systems are analyzed, and a compensation scheme is proposed to improve the system performance. The scheme consists of a joint channel estimation algorithm and a joint data symbol estimation algorithm. In the proposed channel estimation algorithm, the channel coefficients...

Tags: Compensation, Benefits, OFDM, Human Resources, Wireless

White papers 2006-11-19

Adaptive OFDM Techniques With One-Bit-Per-Subcarrier Channel-State Feedback

In the Orthogonal Frequency-Division Multiplexing OFDM scheme, some subcarriers may be subject to a deep fading. Adaptive techniques can be applied to mitigate this effect if the Channel-State Information CSI is available at the transmitter. This paper studies the performance of an OFDM-based communication system whose transmitter has only one...

Tags: Feedback, OFDM, Wireless

White papers 2006-11-01

Dynamic Resource Allocation in OFDM Systems: An Overview of Cross-Layer Optimization Principles and Techniques

Recently, a lot of research effort has been spent on cross-layer system design. It has been shown that cross-layer mechanisms (i.e. policies) potentially provide significant performance gains for various systems. This paper reviews several aspects of cross-layer system optimization regarding wireless OFDM systems. The paper discusses basic optimization models and...

Tags: Technique, Optimization, Allocation, Telecommunication Networks Group, OFDM, Wireless

White papers 2006-10-30