Description: This paper introduces linear constellation precoding
(LCP) for OFDM transmissions over frequency-selective
fading channels. Exploiting the correlation structure
of OFDM subchannels, and choosing system parameters
properly, we first perform optimal subcarrier grouping
to divide the set of correlated subchannels into subsets.
Within each subset, a non-redundant constellation-specijic
unitary precoder is then designed to achieve maximum
multipath diversity and coding gains. While greatly reducing
the decoding complexity and simplifiing the LCP
design, subcarrier grouping offers optimal perjormance by
maximizing multipath diversity and coding gains. In addition,
the proposed system does not sacrifice the transmission
rate. Analytic evaluation and corroborating simulations
reveal its pe$ormance merits. Platform: |
Size: 460800 |
Author:ashish |
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Description: Abstract—2×2 unitary precoding based on receiver feedback
is applied alongside spatial multiplexing at the base station in
HSDPA (D-TxAA) when the mobile terminal supports MIMO
transmissios [1]. This precoding will influence achievable sumrate
of the MIMO channel if it influences the Signal-to-
Interference-plus-Noise Ratio (SINR) of streams at the receiver
(RX) output. We propose a set of MIMO HSDPA receivers, all
based upon a LMMSE chip-level matrix filter (equalizer) front
end, and introduce the notion of joint bias for the MIMO chip
equalizer. Statistical properties of the spatial model thus obtained
are exploited to analyze the performance of proposed MIMO
receivers. It is shown that precoding choice depends upon the
MIMO receiver and the extent of its impact depends on the
MIMO RX. Platform: |
Size: 195584 |
Author:ashish |
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Search - unitary precoding