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Space-Frequency Transmit Diversity In Multiband-OFDM Systems
White Papers The employment of transmit diversity techniques based on block codes is expected to achieve enhancement in such systems since it greatly reduces the detrimental effects of multipath fading. This paper investigates the suitability and performance of...
[April 11, 2007, 0:00]
BER Performance Of OFDM System In Frequency-Selective Rician Fading With Diversity Reception
White Papers In addition, the error probability is determined with the use of diversity reception. This paper theoretically studies the Bit Error Rate (BER) performance of OFDM systems with MDPSK modulation for subchannels in frequency-selective flat Rician...
[April 18, 2007, 0:00]
Diversity Analysis Of Space-Time-Frequency Coded Broadband OFDM Systems
White Papers This paper proposes a general framework for the performance analysis of space-time-frequency coded MIMO-OFDM systems. The approach presented in this paper incorporates the space-time and space-frequency coding approaches as special cases.
[March 30, 2005, 0:00]
Space-Frequency Coded MIMO-OFDM With Variable Multiplexing-Diversity Tradeoff
White Papers Space-frequency coded Orthogonal Frequency Division Multiplexing (OFDM) is capable of realizing both spatial and frequency-diversity gains in multipath multiple-input multiple-output (MIMO) fading channels.
[October 26, 2004, 0:00]
Bit Interleaved Coded Modulation With Space Time Block Codes For OFDM Systems
White Papers Different types of diversity techniques such as temporal, frequency, code, and spatial have been developed in the literature. In addition to the destructive multipath nature of wireless channels, frequency selective channels pose InterSymbol...
[April 11, 2007, 0:00]
Space-Frequency Bit-Interleaved Coded Modulation For MIMO-OFDM/OFDMA Systems
White Papers This paper proposes space-frequency bit-interleaved coded modulation (SF-BICM), which provides both frequency diversity and spatial diversity by interleaving coded bits across transmit antennas and frequency tones.
[March 30, 2005, 0:00]
Iterative Channel Estimation Approach For Space-Time/Frequency Coded OFDM Systems With Transmitter Diversity
White Papers Focusing on transmit diversity orthogonal frequency division multiplexing (OFDM) transmission through frequency selective channels, this paper pursues novel iterative channel estimation approaches for both space-frequency OFDM (SF-OFDM) and space...
[July 31, 2007, 0:00]
On Performance Of Multiuser OFDM Systems With Transmit Diversity
White Papers Performance of multiuser orthogonal frequency division multiplexing (OFDM) systems with transmit diversity over the frequency selective fading channel is explored in this paper. A signal model for the multiuser OFDM system is developed using...
[March 30, 2005, 0:00]
Optimum Pre-DFT Combining With Cyclic Delay Diversity For OFDM Based WLAN Systems
White Papers The cyclic delay diversity is applied in OFDM receiver to increase the frequency-selectivity of the channel seen at the receiver for flat (or less frequency-selective) channels. The diversity combining is performed prior to the Discrete Fourier...
[April 18, 2007, 0:00]
Spatial Transmit Diversity Techniques For Broadband OFDM Systems
White Papers This paper investigates different spatial transmit diversity concepts for orthogonal frequency division multiplexing (OFDM) systems. The achievable performance gains with the proposed transmit diversity concepts are presented for convolutionally...
[March 30, 2005, 0:00]
Orthogonal Delay Diversity Realization And Cyclic Group Codes For MIMO-OFDM
White Papers The delayed orthogonality with respect to frequency tones among different transmitter antennas guarantees to exploit the full spatial and frequency diversity of the frequency-selective multi-input multi-output (MIMO) channel.
[March 30, 2005, 0:00]
High Data Rate MIMO-OFDM System With Orthogonal Delay Diversity Realization
White Papers The delayed orthogonality with respect to frequency tones among different transmitter antennas guarantees to exploit the full spatial and frequency diversity of the frequency-selective multi-input multi-output (MIMO) channel.
[July 26, 2005, 0:00]
Low-Complexity Channel Estimation For Transmitter Diversity OFDM Systems
White Papers This paper proposes a novel low complexity, frequency domain channel estimation algorithm for transmitter diversity OFDM systems. Transmitter diversity can be used with OFDM system for performance improvement in a fading environment.
[July 21, 2005, 0:00]
Space-Time Block-Coded OFDMA With Linear Precoding For Multirate Services
White Papers Relying on space-time linearly precoded orthogonal frequency-division multiple access (OFDMA) and exploiting both transmit and receive antenna diversity, this paper designs herein multirate transceivers that guarantee deterministic symbol recovery...
[March 28, 2005, 0:00]
Slow Subcarrier-Hopped Space Division Multiple Access OFDM Systems
White Papers In this paper the authors devise a Turbo Trellis Coded Modulation (TTCM) assisted subcarrier-based FH/SDMA-OFDM scheme, which may be able to fully exploit the attainable frequency diversity, while exhibiting a high Multi-User-Interference (MUI...
[April 11, 2007, 0:00]
Performance Analysis Of Beamforming For MIMO OFDM With BICM
White Papers It is known that the widely used technique in WLANs, Bit Interleaved Coded Modulation (BICM) with Orthogonal Frequency Division Multiplexing (OFDM), can achieve the maximum frequency diversity order that is inherited in the channel.
[April 13, 2007, 0:00]
Transmit-Antennae Space-Time Block Coding For Generalized OFDM In The Presence Of Unknown Multipath
White Papers Multicarrier precoding maps the frequency-selective channel into a set of flat fading subchannels, whereas space-time encoding/decoding facilitates equalization and achieves performance gains by exploiting the diversity available with multiple...
[October 29, 2004, 0:00]
On The CIR Gain From Location Diversity In GPRS Networks
White Papers Interference diversity by frequency hopping is one proven technology in FDMA systems. A channel carrying multiplexed packet-data from different users can be expected to show interference diversity when acting as a source of interference.
[June 25, 2004, 0:00]
High-Throughput, High-Performance OFDM Via Pseudo-Orthogonal Carrier Interferometry Coding
White Papers The addition of coding, adds both redundancy and frequency diversity, but comes at a cost of reduced overall throughput (typically by a factor of 2). OFDM (Orthogonal Frequency Division Multiplexing) is susceptible to poor probability of error...
[October 16, 2004, 0:00]
OFDMA Code-Division Multiplexing With Pre-Equalization For Mobile Communications
White Papers The code-division multiplexing (CDM) component within an orthogonal frequency-division multiple-access (OFDMA) system enables additional diversity in frequency- and time-selective mobile radio channels.
[October 29, 2004, 0:00]
