YushiShenJan06FreescaleOFDM.rar - This application note gives an overview of the channel estimation strategies used in orthogonal frequency division multiplexing (OFDM) systems. Section 1 describes the protocols associated with OFDM systems and the problems posed by such systems. Section 2 through Section 5 describe the various types of channel estimation methods for use in such systems. The implementation complexity and system performance of the methods are studied and compared in Section 6, measuring performance in terms of symbol error rate (SER).,2010-01-17 23:19:52,下载5次
OFDM_ReceiverDesign.rar - Orthogonal Frequency Division Multiplex (OFDM) system has inherent advantage over single
carrier system in frequency-selective fading channel. It has been adopted by various standards in recent
years including DSL and 802.11a wireless LAN standards.,2010-01-17 23:14:39,下载11次
OFDMsyllabus.rar - SYLLABUS
DSP Theory Review
Sampling
Anti-alias and reconstructions filters
z-domain representation and transforms
FIR and IIR Digital Filters
Poles and zeroes and the Z-domain
Linear non-linear phase
Minimum non-minimum phase,2010-01-17 23:12:01,下载5次
ofdm_matlab.rar - Orthogonal frequency division multiplexing (OFDM) is becoming the chosen
modulation technique for wireless communications. OFDM can provide large data
rates with sufficient robustness to radio channel impairments. Many research centers
in the world have specialized teams working in the optimization of OFDM for
countless applications. Here, at the Georgia Institute of Technology, one of such
teams is in Dr. M. A. Ingram’s Smart Antenna Research Laboratory (SARL), a part
of the Georgia Center for Advanced Telecommunications Technology (GCATT).
The purpose of this report is to provide Matlab code to simulate the basic processing
involved in the generation and reception of an OFDM signal in a physical
channel and to provide a description of each of the steps involved. For this purpose,
we shall use, as an example, one of the proposed OFDM signals of the Digital
Video Broadcasting (DVB) standard for the European terrestrial digital television
(DTV) service.,2010-01-17 23:08:43,下载127次
cdma_ofdm.rar - Up until the end of the 20th century, there was a fairly clear division between the cellular industry and other telecommunication
industries which offered basic telephone, television, radio, computer and Internet services. Most mobile operators used
second generation (2G) digital wireless technologies to enable voice communications and limited data services, while most
wireline, cable and satellite systems provided the bulk of the other telecommunication services. In spite of its initial limitations,
cellular communications have been a tremendous success, surpassing fixed line connections worldwide in 2001, just 12
years after its market introduction. This has been especially evident in developing markets where, due to their lower
deployment costs and greater network flexibility, wireless technologies have become the primary means of communication
for millions of people, spurring the economic and social development of these markets.,2010-01-17 23:05:53,下载3次
OFDM_presentation.rar - ofdm presenatation:
L OFDM (Orthogonal Frequency Division Multiplexing) est une technique de
transmission très performante pour les réseaux sans fil à hauts débits numériques. Dans
un système OFDM, la bande de fréquence est divisée en des multiples sous-porteuses
orthogonales. Les usagers présents dans le système se partagent ces sous-porteuses pour
échanger les données avec la station de base.
Les accès multiples basés sur l OFDM ont de sérieuses chances d être utilisées dans les
réseaux mobiles de troisième génération et autres boucles locales radio ou BLR. Ils le
sont déjà dans certains systèmes de BLR et WLAN.
L objet de ce rapport est l étude de la capacité des réseaux sans fil de type OFDMA
(technique d accès multiple basée sur l OFDM).,2010-01-08 18:18:11,下载6次
PAPR_OFDMprc.rar - PEAK TO AVERAGE POWER RATIO REDUCTION OF OFDM
SIGNALS USING PEAK REDUCTION CARRIERS:
ABSTRACT
A technique is described for a better than 5 dB reduction
in the Peak to Average Power Ratio (PAPR) of an OFDM
signal. The optimal amplitude and phase of additional
peak reduction carriers (PRC) is obtained using a codebook,
which is obtained using a search of all possible
signal combinations.,2010-01-08 18:05:28,下载89次
Les_technologies_sans_fil.rar - Les technologies sans fil:
Les solutions (Wireless) sont plus qu à la mode, quasi incontournables. Entre Airport, Bluetooth, Wireless LAN et autres, l utilisateur a quelque excuse de se sentir un peu (largué). Peut-on faire une nomenclature comparative des diverses solutions qui s offrent à l utilisateur en fonction de l utilisation, du débit, des éléments et des systèmes d exploitation incriminés. Ces solutions ont-elles encore une raison d être du moment qu il faut se raccorder au réseau 220V ,2010-01-08 18:02:20,下载6次
hanzo_OFDM.rar - OFDM and MC-CDMA
for Broadband Multi-user Communications, WLANs
and Broadcasting,2010-01-08 17:57:15,下载35次
ICI_OFDM.rar - INTER-CARRIER INTERFERENCE CANCELLATION FOR OFDM SYSTEMS:
Orthogonal Frequency Division Multiplexing (OFDM) is an emerging multi-carrier modulation scheme, which has been adopted for several wireless standards such as IEEE 802.11a and HiperLAN2. A well-known problem of OFDM is its sensitivity to frequency offset between the transmitted and received carrier frequencies. This frequency offset introduces inter-carrier interference (ICI) in the OFDM symbol. This project investigates three methods for combating the effects of ICI: ICI self-cancellation (SC), maximum likelihood (ML) estimation, and extended Kalman filter (EKF) method. These three methods are compared in terms of bit error rate performance, bandwidth efficiency, and computational complexity. Through simulations, it is shown that the three techniques are effective in mitigating the effects of ICI. For high values of the frequency offset and for higher order modulation schemes, the ML and EKF methods perform better than the SC method.,2010-01-08 17:54:56,下载261次