60 research outputs found
Tomlinson Harashima precoding design for non-regenerative MIMO relay networks
In this paper we consider the design of minimum mean square error (MMSE) transceivers for non-regenerative multiple input multiple output (MIMO) relay systems. Our design utilises Tomlinson Harashima precoding (THP) at the source along with linear processors in each stage of the network. Assuming full channel state information (CSI) is available at each node in the network the various processors are jointly optimised to minimise the system arithmetic mean square error (MSE) whilst abiding by average power constraints at both the source and relay terminals in the network. Simulations show that the proposed schemes outperform existing methods in terms of bit error ratio (BER)
Matrix-Monotonic Optimization for MIMO Systems
For MIMO systems, due to the deployment of multiple antennas at both the
transmitter and the receiver, the design variables e.g., precoders, equalizers,
training sequences, etc. are usually matrices. It is well known that matrix
operations are usually more complicated compared to their vector counterparts.
In order to overcome the high complexity resulting from matrix variables, in
this paper we investigate a class of elegant multi-objective optimization
problems, namely matrix-monotonic optimization problems (MMOPs). In our work,
various representative MIMO optimization problems are unified into a framework
of matrix-monotonic optimization, which includes linear transceiver design,
nonlinear transceiver design, training sequence design, radar waveform
optimization, the corresponding robust design and so on as its special cases.
Then exploiting the framework of matrix-monotonic optimization the optimal
structures of the considered matrix variables can be derived first. Based on
the optimal structure, the matrix-variate optimization problems can be greatly
simplified into the ones with only vector variables. In particular, the
dimension of the new vector variable is equal to the minimum number of columns
and rows of the original matrix variable. Finally, we also extend our work to
some more general cases with multiple matrix variables.Comment: 37 Pages, 5 figures, IEEE Transactions on Signal Processing, Final
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Transceiver design for non-regenerative MIMO relay systems with decision feedback detection
In this paper we consider the design of zero forcing (ZF) and minimum mean square error (MMSE) transceivers for non-regenerative multiple input multiple output (MIMO) relay networks. Our designs utilise linear processors at each stage of the network along with a decision feedback detection device at the receiver. Under the assumption of full channel state information (CSI) across the entire link the processors are jointly optimised to minimise the system arithmetic mean square error (MSE) whilst meeting average power constraints at both the source and the relay terminals. We compare the presented methods to linear designs available in the literature and show the advantages of the proposed transceivers through simulation results
ZF DFE transceiver design for MIMO relay systems with direct source-destination link
In this paper we consider a non-linear transceiver design for non-regenerative multiple-input multiple-output (MIMO) relay networks where a direct link exists between the source and destination. Our system utilises linear processors at the source and relay as well as a zero-forcing (ZF) decision feedback equaliser (DFE) at the receiver. Under the assumption that full channel state information (CSI) is available the precoding and equaliser matrices are designed to minimise the arithmetic mean square error (MSE) whilst meeting transmit power constraints at the source and destination. The source, relay, and destination processors are provided in closed form solution. In the absence of the direct link our design particularises to a previous ZF DFE solution and as such can be viewed as a generalisation of an existing work. We demonstrate the effectiveness of the proposed solution through simulation and show that it outperforms existing techniques in terms of bit error ratio (BER)
Reliable indoor power line communication systems: via application of advanced relaying processing
In this thesis, we focus on improving the performance of indoor power line communication (PLC) systems using relaying schemes. A method of modelling relay-involved PLC channels has been proposed. We study the optimal joint transceiver and relay power allocation problem for relay-assisted multicarrier indoor PLC systems. We transform the nonconvex problem into a group of sub-problems which can be efficiently solved using standard convex optimization techniques. The proposed schemes outperform conventional direct PLC systems
OFDM Communication with Cooperative Relays
Signal fading due to multi-path propagation is one of the major impairments to meet the demands of next generation wireless networks for high data rate services. To mitigate the fading effects, time, frequency, and spatial diversity techniques or their hybrid can be used. Among different types of diversity techniques, spatial diversity is of special interest as is does not incur system losses in terms of delay and bandwidth efficiency.TelecommunicationsElectrical Engineering, Mathematics and Computer Scienc
Efficient cooperative OFMD localization
The author of this project has been working on the topic of cooperative OFDM localization for one year in the TU
Delft as an exchange student. Nowadays there are many potential uses for cooperative
localization in places in which the common systems like GPS could not provide an accurate
estimation. It is an advantage to join into a wireless network with a mobile device and be
able to navigate and know your position. Two critical points in this topic are the accuracy of
the localization, that is required to be high, and the power consumption of the mobile
devices, which is a critical resource. Existing indoor cooperative localization methods require
big battery consumption for the mobile relays, and the accuracy in low SNR situations is not
good enough. The scope of this thesis is to estimate the localization of an unknown mobile
device in an efficient way, being accurate even in low SNR situations, with low power
consumption. One first approximation and the reference [11] suggested the idea of the
“feature method” which is a bandwidth efficient cooperative ZP-OFDM localization method.
After testing different features and conclude that the peak to average power ratio has the
best performance another new idea came up. A new simple relay is proposed, called
trigger relay, which consists of forwarding a known signal when the incoming signal is
received. With this new idea it is solved the bandwidth and computational problem, being
the most efficient method to estimate the TDOA. This brilliant idea was published in the
PIMRC conference in September, 2011.Ingeniería de TelecomunicaciónTelekomunikazio Ingeniaritz
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