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1.
Patrick N. Troy 《Housing Studies》1992,7(3):216-233
This paper sets out the development of four main threads of housing policy in New South Wales from the latter part of the 19th century through the first 40 years of the 20th century. Following a discussion of the social and political circumstances and debate surrounding government policy regarding landlord/tenant relations, housing quality and supply, and owner occupancy, it concludes that policy evolution is irregular and a product of the exigencies of the political process. It also suggests that although government policy did little to improve the housing situation for the underprivileged, there was nevertheless a growing acceptance by both Labor and conservative parties of the increased need for government intervention in the housing market. 相似文献
2.
The authors propose techniques for adaptive nonlinear cancellation of intersymbol interference (ISI) in the electrical signal at the receiver in Gb/s lightwave systems and describe several demonstrations of these techniques. Techniques for adjustable nonlinear cancellations are discussed and demonstrations of these techniques using commercially available integrated circuits (ICs) at data rates as high as 1.7 Gb/s are described. Techniques for automatic adjustment are discussed, and a demonstration of adaptive nonlinear cancellation at 450 Mb/s is described. The authors discuss how these techniques can be integrated onto the detector IC for operations at 2.5 Gb/s and higher data rates. These techniques allow a single IC detector with adaptive nonlinear cancellation to be used in long-haul and undersea lightwave systems to optimize the detector threshold and compensate for the ISI 相似文献
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In this paper, we study the ability of transmit diversity to provide diversity benefit to a receiver in a Rayleigh fading environment. With transmit diversity, multiple antennas transmit delayed versions of a signal to create frequency-selective fading at a single antenna at the receiver, which uses equalization to obtain diversity gain against fading. We use Monte Carlo simulation to study transmit diversity for the case of independent Rayleigh fading from each transmit antenna to the receive antenna and maximum likelihood sequence estimation for equalization at the receiver. Our results show that transmit diversity with M transmit antennas provides a diversity gain within 0.1 dB of that with M receive antennas for any number of antennas. Thus, we can obtain the same diversity benefit at the remotes and base stations using multiple base-station antennas only 相似文献
5.
MIMO-OFDM for wireless communications: signal detection with enhanced channel estimation 总被引:4,自引:0,他引:4
Multiple transmit and receive antennas can be used to form multiple-input multiple-output (MIMO) channels to increase the capacity by a factor of the minimum number of transmit and receive antennas. In this paper, orthogonal frequency division multiplexing (OFDM) for MIMO channels (MIMO-OFDM) is considered for wideband transmission to mitigate intersymbol interference and enhance system capacity. The MIMO-OFDM system uses two independent space-time codes for two sets of two transmit antennas. At the receiver, the independent space-time codes are decoded using prewhitening, followed by minimum-Euclidean-distance decoding based on successive interference cancellation. Computer simulation shows that for four-input and four-output systems transmitting data at 4 Mb/s over a 1.25 MHz channel, the required signal-to-noise ratios (SNRs) for 10% and 1% word error rates (WER) are 10.5 dB and 13.8 dB, respectively, when each codeword contains 500 information bits and the channel's Doppler frequency is 40 Hz (corresponding normalized frequency: 0.9%). Increasing the number of the receive antennas improves the system performance. When the number or receive antennas is increased from four to eight, the required SNRs for 10% and 1% WER are reduced to 4 dB and 6 dB, respectively. Therefore, MIMO-OFDM is a promising technique for highly spectrally efficient wideband transmission. 相似文献
6.
Chiani M. Win M.Z. Zanella A. Winters J.H. 《Wireless Communications, IEEE Transactions on》2004,3(1):12-16
We derive a simple closed-form upper bound on the symbol error probability for coherent detection of M-ary phase-shift keying using antenna arrays with optimum combining, in the presence of multiple uncorrelated equal-power cochannel interferers and thermal noise in a Rayleigh fading environment. The new bound, based on Laguerre polynomials, is valid for an arbitrary number of antenna elements as well as arbitrary number of interferers, and it is proven to be asymptotically tight. Comparisons with Monte Carlo simulation are also provided, showing that our bound is useful in many cases of interest. 相似文献
7.
Keirnan R. LaMarche Stephen L. Conway Benjamin J. Glasser Troy Shinbrot 《Granular Matter》2007,9(3-4):219-229
A cellular automata model is used to simulate a variety of granular chute flows. The model is tested against several case
studies: flow down a chute, flow past an obstacle, chute flow in which complex, counter-rotating vortices result in streamwise
surface stripes and flow near a boundary. The model successfully reproduces experimental observations in all of these cases.
These results lead us to propose that simple, rule-based, models such as this can improve our detailed understanding of dynamics
and flow within an opaque granular bed. 相似文献
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