In this paper, the effect of keyhole on the performance of multiple-input multiple-output (MIMO) amplify-and-forward (AF) relay networks with orthogonal space-time block codes (OSTBCs) transmission is investigated. In...
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In this paper, the effect of keyhole on the performance of multiple-input multiple-output (MIMO) amplify-and-forward (AF) relay networks with orthogonal space-time block codes (OSTBCs) transmission is investigated. In particular, we analyze the asymptotic symbol error probability (SEP) performance of a downlink communication system where the amplifying processing at the relay can be implemented by either the linear or squaring approach. Our tractable asymptotic SEP expressions enable us to obtain both diversity and array gains. Our finding reveals that with condition n(S) > min(n(R), n(D)), the linear approach can provide the full achievable diversity gain of min(n(R), n(D)) when only the second hop suffers from the keyhole effect, i.e., single keyhole effect (SKE), where n(S), n(R), and n(D) are the number of antennas at source, relay, and destination, respectively. However, for the case that both the source-relay and relay-destination links experience the keyhole effect, i.e., double keyhole effect (DKE), the achievable diversity order is only one regardless of the number of antennas. In contrast, utilizing the squaring approach, the overall diversity gain can be achieved as min(n(R), n(D)) for both SKE and DKE. An important observation corroborated by our studies is that for satisfying the tradeoff between performance and complexity, we should use the linear approach for SKE and the squaring approach for DKE.
This paper will analyse the RLS algorithm and its improved algorithms, QRD-RLS and IQRD-RLS algorithms. QRD-RLS and IQRD-RLS algorithms can reduce the complexity of RLS algorithm effectively. Then, we apply these thre...
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This paper will analyse the RLS algorithm and its improved algorithms, QRD-RLS and IQRD-RLS algorithms. QRD-RLS and IQRD-RLS algorithms can reduce the complexity of RLS algorithm effectively. Then, we apply these three algorithms in MIMO-OFDM system, and we do some simulations on these three algorithms. From the simulation, we can see that the performance of the QRD-RLS and IQRD-RLS algorithms is better than RLS algorithm.
A novel vertical Bell laboratories layered space-time(V-BLAST)system with adaptive successive interference cancellation(SIC)detector based on subspace tracking(SST)and Hermitian matrix perturbation theorem is proposed...
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A novel vertical Bell laboratories layered space-time(V-BLAST)system with adaptive successive interference cancellation(SIC)detector based on subspace tracking(SST)and Hermitian matrix perturbation theorem is proposed in this paper,and the corresponding optimal symbol detection order operation is ***,asymptotic limit theorems for the detectors are *** final simulation results verify that the symbol error probability(SEP)performance,the immunity to channel estimation errors and the algorithm convergence rate are superior to that of the conventional V-BLAST detection algorithm when channel estimation errors exist.
In this paper, we propose novel algorithms for optimal power allocation towards video transmission in orthogonal frequency division multiple access (OFDMA) and multiple-input multiple-output (MIMO)-based 4G networks. ...
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In this paper, we propose novel algorithms for optimal power allocation towards video transmission in orthogonal frequency division multiple access (OFDMA) and multiple-input multiple-output (MIMO)-based 4G networks. A unique feature of the schemes is that they employ diversity dependent subcarrier power distribution relying on a discrete wavelet transform (DWT)-based hierarchical video decomposition, with exclusively order statistics-based partial channel state information (CSI). This is formulated as a convex minimisation problem and closed form expressions are derived for diversity-based optimal power allocation. We also propose novel algorithms for diversity order-based optimal power allocation for video transmission in MIMO systems. Further, we consider a practical MIMO scenario and employ a limited feedback technique utilising the index of the quantised beamforming vector. A closed form expression for the optimal power allocation is presented based on an iterative convex optimisation framework. Simulation results demonstrate superior performance of the proposed optimal power allocation schemes.
We consider a single-hop interference network with K transmitters and J receivers, all having M antennas. Each transmitter emits an independent message and each receiver requests an arbitrary subset of the messages. T...
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We consider a single-hop interference network with K transmitters and J receivers, all having M antennas. Each transmitter emits an independent message and each receiver requests an arbitrary subset of the messages. This generalizes the well-known K-user M-antenna interference channel, where each message is requested by a unique receiver. For our setup, we derive the degrees of freedom (DoF) region. The achievability scheme generalizes the interference alignment schemes proposed by Cadambe and Jafar. In particular, we achieve general points in the DoF region by using multiple base vectors and aligning all interferers at a given receiver to the interferer with the largest DoF. As a byproduct, we obtain the DoF region for the original interference channel. We also discuss extensions of our approach where the same region can be achieved by considering a reduced set of interference alignment constraints, thus reducing the time-expansion duration needed. The DoF region for the considered system depends only on a subset of receivers whose demands meet certain characteristics. The geometric shape of the DoF region is also discussed.
We proposed a mode group delay managed transmission line for a WDM-MIMO system consisting of fibers with positive and negative DMDs to compensate for the total DMD. We show numerically that the multi-step index fiber ...
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We proposed a mode group delay managed transmission line for a WDM-MIMO system consisting of fibers with positive and negative DMDs to compensate for the total DMD. We show numerically that the multi-step index fiber can flexibly tune the DMD. We fabricated fibers for use in a C-L band WDM-MIMO system, and realized a 20.4 km-long DMD compensated transmission line with a total absolute DMD of less than 111 ps over the entire C-L band. Finally, we achieved a 2 x 2 WDM-MIMO transmission within the C-L band by using equalizers with a small tap number.
multi-user multiple-input multiple-output (MIMO) system with multiple data streams per user and quantized channel state information at the transmitter. We minimize the sum mean squared error (SMSE) under a sum power c...
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ISBN:
(纸本)9781467358293;9781467358309
multi-user multiple-input multiple-output (MIMO) system with multiple data streams per user and quantized channel state information at the transmitter. We minimize the sum mean squared error (SMSE) under a sum power constraint with quantization based on the mean squared inner product. We make three contributions: (i) we remove dimensionality constraints on the MIMO configuration and the resulting feedback overhead scales linearly with the number of data streams;(ii) we use the combination of eigenmode combining and minimum mean square error receiver that makes user's feedback mutually independent;(iii) we analyze SMSE at high signal-to-noise ratio and large number of transmit antennas and derive an approximate SMSE floor.
In this paper, the channel capacity of a multipleinputmultipleoutput (MIMO) broadcast system is investigated under correlated fading environment where there exists a transmitter, a legitimate receiver and an eavesd...
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ISBN:
(纸本)9781612846835;9781612846828
In this paper, the channel capacity of a multipleinputmultipleoutput (MIMO) broadcast system is investigated under correlated fading environment where there exists a transmitter, a legitimate receiver and an eavesdrop, each node equipped with multiple antennas. We derive the secret capacity and its upper bound of the MIMO broadcast channel in detail by using the Information theory and random matrices theory.
multiple-input multiple-output (MIMO) systems are capable of simultaneously capturing more than one packet. Such capability is known as Multi-Packet Reception (MPR), which is new way to improve performance of Ad Hoc N...
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ISBN:
(纸本)9781612846835;9781612846828
multiple-input multiple-output (MIMO) systems are capable of simultaneously capturing more than one packet. Such capability is known as Multi-Packet Reception (MPR), which is new way to improve performance of Ad Hoc Networks. In order to effectively enhance throughput of Ad Hoc Networks, a novel MAC protocol (MIMO-MAC) with MIMO links that takes into account MPR is proposed. It can receive more than one RTS before responding CTS, which maximizes transmission links simultaneously. Receiver determines links according to the number of its own antennas and RTS. Compare to the existing protocol, it allows many communications at the same time in one competitive area. Finally, simulations are implemented in terms of load and source nodes number in OPNET environment, results show that MIMO-MAC outperforms CSMA/CA and CSMA/CA (k).
Motivated by recently presented integer-forcing linear receiver architecture, we propose algorithms to design optimal integer-forcing coefficient matrix such that the total achievable rate is maximized.
ISBN:
(纸本)9781467309219;9781467309202
Motivated by recently presented integer-forcing linear receiver architecture, we propose algorithms to design optimal integer-forcing coefficient matrix such that the total achievable rate is maximized.
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