Transmitter diversity for OFDM systems and its impacts on high-rate wireless networks

Li, Y.; Chuang, J.C.-I.; Sollenberger, N.R.

doi:10.1109/icc.1999.767996

Cited by 12 publications

(9 citation statements)

References 16 publications

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“…Antenna virtualization is a method applied at the transmitter wherein the N transmitter antennas are virtualized to a single transmit antenna from the receiver perspective. One form of antenna virtualization is cyclic delay diversity (CDD) [9]. In CDD the signals at antennas n = 2, .…”

Section: The System Modelmentioning

confidence: 99%

Statistical distributions that arise in constrained beamforming with incomplete channel information

Hochwald¹,

Jalloul²

2010

2010 Information Theory and Applications Workshop (ITA)

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Abstract-We examine the statistical distribution of received power when a subscriber terminal with multiple transmit antennas beamforms on the uplink of a wireless orthogonal frequencydivision multiplexing system to a basestation with multiple receive antennas. We assume that a time-division duplex terminal has incomplete uplink channel knowledge obtained by measuring the downlink channel during basestation transmissions. The basestation transmissions employ cyclic delay diversity, of which the terminal is unaware. The distribution of uplink power received at the basestation, with and without downlink cyclic delay diversity and with various types of power constraints at the terminal, allow us to make some surprising conclusions about how the power constraints and cyclic delay influence the performance of beamforming. We show that beamforming gains need to be examined critically beyond simple average performance metrics to conclude that they are superior to simpler channel-unaware methods. We also conclude that cyclic delay on the downlink is very beneficial to beamforming on the uplink, even with restrictive types of power constraints.

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Section: The System Modelmentioning

confidence: 99%

Statistical distributions that arise in constrained beamforming with incomplete channel information

Hochwald¹,

Jalloul²

2010

2010 Information Theory and Applications Workshop (ITA)

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“…Channel estimation for single-and multiuser ST-coded systems in frequency-selective channels has been considered in, for example, [5,[8][9][10][11]. Those studies all assume multicarrier modulation which converts a frequencyselective channel into a set of nonoverlapping frequency-nonselective sub-channels.…”

Section: Introductionmentioning

confidence: 99%

Blind channel estimation and detection for space–time coded CDMA in ISI channels

Sun

2007

Digital Signal Processing

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“…O RTHOGONAL frequency division multiplexing (OFDM) [1]- [6] is a potential technique for transmitting high-bitrate data over indoor and outdoor wireless communication systems. Channel parameter estimation is an important technique for further improving data transmission performance.…”

Section: Introductionmentioning

confidence: 99%

“…The decision-directed parameter estimators have been used in OFDM systems for coherent detection [7]- [9], co-channel interference suppression [10], [11] and transmitter diversity [6], [12], [13]. For systems that are noise limited or with little co-channel interference, coherent demodulation with estimated channel parameters [7]- [9] can be used instead of differential demodulation, and it can achieve a 2.5-3 dB signal-to-noise ratio (SNR) gain.…”

Section: Introductionmentioning

confidence: 99%

Pilot-symbol-aided channel estimation for OFDM in wireless systems

2000

IEEE Trans. Veh. Technol.

503

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In this paper, we investigate pilot-symbol-aided parameter estimation for orthogonal frequency division multiplexing (OFDM) systems. We first derive a minimum mean-square error (MMSE) pilot-symbol-aided parameter estimator. Then, we discuss a robust implementation of the pilot-symbol-aided estimator that is insensitive to channel statistics. From the simulation results, the required signal-to-noise ratios (SNR's) for a 10% word error rate (WER) are 6.8 dB and 7.3 dB for the typical urban (TU) channels with 40 Hz and 200 Hz Doppler frequencies, respectively, and they are 8 dB and 8.3 dB for the hilly-terrain (HT) channels with 40 Hz and 200 Hz Doppler frequencies, respectively. Compared with the decision-directed parameter estimator, the pilot-symbolaided estimator is highly robust to Doppler frequency for dispersive fading channels with noise impairment even though it has some performance degradation for systems with lower Doppler frequencies.

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Transmitter diversity for OFDM systems and its impacts on high-rate wireless networks

Cited by 12 publications

References 16 publications

Statistical distributions that arise in constrained beamforming with incomplete channel information

Statistical distributions that arise in constrained beamforming with incomplete channel information

Blind channel estimation and detection for space–time coded CDMA in ISI channels

Pilot-symbol-aided channel estimation for OFDM in wireless systems

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