45 research outputs found
On Max-SINR Receiver for Hexagonal Multicarrier Transmission Over Doubly Dispersive Channel
In this paper, a novel receiver for Hexagonal Multicarrier Transmission (HMT)
system based on the maximizing Signal-to-Interference-plus-Noise Ratio
(Max-SINR) criterion is proposed. Theoretical analysis shows that the prototype
pulse of the proposed Max-SINR receiver should adapt to the root mean square
(RMS) delay spread of the doubly dispersive (DD) channel with exponential power
delay profile and U-shape Doppler spectrum. Simulation results show that the
proposed Max-SINR receiver outperforms traditional projection scheme and
obtains an approximation to the theoretical upper bound SINR performance within
the full range of channel spread factor. Meanwhile, the SINR performance of the
proposed prototype pulse is robust to the estimation error between the
estimated value and the real value of time delay spread.Comment: 6 pages. The paper has been published in Proc. IEEE GLOBECOM 2012.
Copyright transferred to IEEE. arXiv admin note: text overlap with
arXiv:1212.579
Alternative Awaiting and Broadcast for Two-Way Relay Fading Channels
We investigate a two-way relay (TWR) fading channel where two source nodes
wish to exchange information with the help of a relay node. Given traditional
TWR protocols, transmission rates in both directions are known to be limited by
the hop with lower capacity, i.e., the min operations between uplink and
downlink. In this paper, we propose a new transmission protocol, named as
alternative awaiting and broadcast (AAB), to cancel the min operations in the
TWR fading channels. The operational principles, new upper bound on ergodic
sum-capacity (ESC) and convergence behavior of average delay of signal
transmission (ST) (in relay buffer) for the proposed AAB protocol are analyzed.
Moreover, we propose a suboptimal encoding/decoding solution for the AAB
protocol and derive an achievable ergodic sum-rate (ESR) with corresponding
average delay of ST. Numerical results show that 1) the proposed AAB protocol
significantly improves the achievable ESR compared to the traditional TWR
protocols, 2) considering the average delay of system service (SS) (in source
buffer), the average delay of ST induced by the proposed AAB protocol is very
small and negligible.Comment: to appear in IEEE Transactions on Vehicular Technology, 201
Pairwise Check Decoding for LDPC Coded Two-Way Relay Block Fading Channels
Partial decoding has the potential to achieve a larger capacity region than
full decoding in two-way relay (TWR) channels. Existing partial decoding
realizations are however designed for Gaussian channels and with a static
physical layer network coding (PLNC). In this paper, we propose a new solution
for joint network coding and channel decoding at the relay, called pairwise
check decoding (PCD), for low-density parity-check (LDPC) coded TWR system over
block fading channels. The main idea is to form a check relationship table
(check-relation-tab) for the superimposed LDPC coded packet pair in the
multiple access (MA) phase in conjunction with an adaptive PLNC mapping in the
broadcast (BC) phase. Using PCD, we then present a partial decoding method,
two-stage closest-neighbor clustering with PCD (TS-CNC-PCD), with the aim of
minimizing the worst pairwise error probability. Moreover, we propose the
minimum correlation optimization (MCO) for selecting the better
check-relation-tabs. Simulation results confirm that the proposed TS-CNC-PCD
offers a sizable gain over the conventional XOR with belief propagation (BP) in
fading channels.Comment: to appear in IEEE Trans. on Communications, 201
Max-SINR Receiver for HMCT Systems over Non-Stationary Doubly Dispersive Channel
In this paper, a maximizing Signal-to-Interference plus-Noise Ratio
(Max-SINR) receiver for Hexagonal Multicarrier Transmission (HMCT) system over
non-stationary doubly dispersive (NSDD) channel is proposed. The closed-form
timing offset expression of the prototype pulse for the proposed Max-SINR HMCT
receiver over NSDD channel is derived. Simulation results show that the
proposed Max-SINR receiver outperforms traditional projection scheme and
obtains an approximation to the theoretical upper bound SINR performance within
all the local stationarity regions (LSRs). Meanwhile, the SINR performance of
the proposed Max-SINR HMCT receiver is robust to the estimation error between
the estimated value and the real value of root mean square (RMS) delay spread.Comment: This paper has been accepted by URSI GASS 2014 and will be presented
in the proceeding of URSI GASS 201