5,141 research outputs found
Auto-Generation of Pipelined Hardware Designs for Polar Encoder
This paper presents a general framework for auto-generation of pipelined
polar encoder architectures. The proposed framework could be well represented
by a general formula. Given arbitrary code length and the level of
parallelism , the formula could specify the corresponding hardware
architecture. We have written a compiler which could read the formula and then
automatically generate its register-transfer level (RTL) description suitable
for FPGA or ASIC implementation. With this hardware generation system, one
could explore the design space and make a trade-off between cost and
performance. Our experimental results have demonstrated the efficiency of this
auto-generator for polar encoder architectures
Determinant Representation of Correlation Functions for the Free Fermion Model
With the help of the factorizing -matrix, the scalar products of the
free fermion model are represented by determinants. By means of
these results, we obtain the determinant representations of correlation
functions of the model.Comment: Latex File, 20 pages, V.3: some discussions are added, V.4 Reference
update, this version will appear in J. Math. Phy
Drinfeld twists and algebraic Bethe ansatz of the supersymmetric model associated with
We construct the Drinfeld twists (or factorizing -matrices) of the
supersymmetric model associated with quantum superalgebra , and
obtain the completely symmetric representations of the creation operators of
the model in the -basis provided by the -matrix. As an application of our
general results, we present the explicit expressions of the Bethe vectors in
the -basis for the -model (the quantum t-J model).Comment: Latex file, 33 pages; V2: minor typos corrected;V3: Reference update,
the new version will appear in Commun. Maths. Phys;V4: misprints correcte
Channel Acquisition for Massive MIMO-OFDM with Adjustable Phase Shift Pilots
We propose adjustable phase shift pilots (APSPs) for channel acquisition in
wideband massive multiple-input multiple-output (MIMO) systems employing
orthogonal frequency division multiplexing (OFDM) to reduce the pilot overhead.
Based on a physically motivated channel model, we first establish a
relationship between channel space-frequency correlations and the channel power
angle-delay spectrum in the massive antenna array regime, which reveals the
channel sparsity in massive MIMO-OFDM. With this channel model, we then
investigate channel acquisition, including channel estimation and channel
prediction, for massive MIMO-OFDM with APSPs. We show that channel acquisition
performance in terms of sum mean square error can be minimized if the user
terminals' channel power distributions in the angle-delay domain can be made
non-overlapping with proper phase shift scheduling. A simplified pilot phase
shift scheduling algorithm is developed based on this optimal channel
acquisition condition. The performance of APSPs is investigated for both one
symbol and multiple symbol data models. Simulations demonstrate that the
proposed APSP approach can provide substantial performance gains in terms of
achievable spectral efficiency over the conventional phase shift orthogonal
pilot approach in typical mobility scenarios.Comment: 15 pages, 4 figures, accepted for publication in the IEEE
Transactions on Signal Processin
Supersymmetric Vertex Models with Domain Wall Boundary Conditions
By means of the Drinfeld twists, we derive the determinant representations of
the partition functions for the and supersymmetric vertex
models with domain wall boundary conditions. In the homogenous limit, these
determinants degenerate to simple functions.Comment: 19 pages, 4 figures, to be published in J. Math. Phy
Motion Structures
Motion structures are simply assemblies of resistant bodies connected by movable joints. Unlike conventional structures, they allow large shape transformations to satisfy practical requirements and they can be used in:shelters, emergency structures and exhibition standsaircraft morphing wingssatellite solar panels and space antennasmorphing core m
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