4,953 research outputs found
New Union Bound on the Error Probability of Bit-Interleaved Space-Time Codes with Finite Interleaver Sizes
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Performance Analysis of Coded Cooperation Diversity in Wireless Networks
Full text linkDiversity is an effective technique in enhancing the link quality and increasing network capacity. When multiple antennas can not be used in mobile units, user cooperation can be employed to provide transmit diversity. In this paper we analyze the error performance of coded cooperation diversity with multiple cooperating users. We derive the end-to-end bit error probability of coded cooperation (averaged over all cooperation scenarios). We consider different fading distributions for the interuser channels. Furthermore, we consider the case of two cooperating users with correlated uplink channels. Results show that more cooperating users should be allowed under good interuser channel conditions, while it suffices to have two cooperating users in adverse interuser conditions. Furthermore, under bad interuser conditions, more cooperating users can be accommodated as the fading distribution becomes more random
Union Bounds on the Bit Error Probability of Coded MRC in Nakagami-m Fading
Full text linkIn this letter new union bounds are derived for coded maximal ratio combining (MRC) over Nakagami-m fading channels. The union bounds are expressed in the product form, which makes them easily, evaluated using the transfer function of the code. The bounds are general to any diversity order and coding scheme with a known transfer function. Results show that the new bounds are tight to simulation results for wide ranges of diversity orders and Nakagami parameter
Dredging Processes I: The Cutting of Sand, Clay & Rock - Theory
No full textThis book gives an overview of cutting theories. It starts with a generic model, which is valid for all types of soil (sand, clay and rock) after which the specifics of dry sand, water saturated sand, clay, rock and hyperbaric rock are covered. For each soil type small blade angles and large blade angles, resulting in a wedge in front of the blade, are discussed. The failure mechanism of sand, dry and water saturated, is the so called Shear Type. The failure mechanism of clay is the so called Flow Type, but under certain circumstances also the Curling Type and the Tear Type are possible. Rock will usually fail in a brittle way. This can be brittle tensile failure, the Tear Type, for small blade angles, but it can also be brittle shear failure, which is of the Shear Type of failure mechanism for larger blade angles. Under hyperbaric conditions rock may also fail in a more ductile way according to the Flow Type of failure mechanism. For each case considered, the equations/model for the cutting forces, power and specific energy are given. The models are verified with laboratory research, mainly at the Delft University of Technology, but also with data from literature.Marine & Transport TechnologyMechanical, Maritime and Materials Engineerin
Work among Japanese in the Salt River Valley of Arizona
No full textDocument written by S.A. Stewart Resident Missionary, East Kyushu Distict, Japan Methodist Church. Stewart discusses the events at the church and the free and restricted zones for Japanese Americans living in Glendale and Phoenix, Arizona.The Bishop James Chamberlain Baker Collection includes letters, documents, and articles about Japanese Americans during World War II. Subjects in the collection include Japanese Americans mass removal, Pearl Harbor and the aftermath, religion, and support from the non-Japanese American community. The collection was digitized and made accessible online by CSUDH Gerth Archives and Special Collections
A tight bound on the error probability of space-time codes forrapid fading channels
Full text linkThis paper presents the performance of space-time (ST) codes over rapid fading channels. A tight upper bound on the pairwise error probability (PWEP) of ST codes over rapid fading channels is derived. Also, an upper bound on the bit error probability (BEP) is evaluated using the derived PWEP. The existing and new bounds are evaluated for different QPSK ST codes and compared to the simulation results. The new bound is shown to be tighter than the existing bound by almost 2 dBs and is very tight to the simulation result
Space-time coded QPSK for rapid fading channels
Full text linkThis paper presents the design of space-time codes suitable for rapid fading channels. The codes are designed using the QPSK signal constellation. The design of the proposed codes utilizes two different encoding methods. The first method uses a large time diversity trellis encoder, and the second one uses the I-Q encoding technique. Both methods are expected to produce space-time codes that perform better than the codes presented in the literature. The proposed codes were simulated over different Rayleigh fading channels. Coding gains up to 3 dB have been observed over similar codes in the literatur
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