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We investigate error performance and an optimum power allocation scheme for multiple-input multiple-output (MIMO) channel physical layer network coding (PNC) based two-way relay system. Zero forcing precoding technique is used at source nodes to facilitate PNC operations at the relay node. First, system error performance is investigated by introducing upper and lower bounds for BPSK modulation system...
We consider physical network coding on a two-way relay channel. Two source nodes send their packets simultaneously over time-varying MIMO channels to a relay node. Assuming that the relay employs the joint decode-and-forward strategy, the relay must be able to decode the individual source packets. This task requires a robust estimation of the source-to-relay channels. We design a message passing algorithm...
In this paper, the source and relay transmit covariance matrices are jointly optimized for a fading multiple antenna relay channel when the transmitters only have partial channel state information (CSI) in the form of covariance feedback. For full-duplex transmission, we evaluate lower and upper bounds on the ergodic channel capacity. These bounds require a joint optimization over the source and relay...
During the operation of multiuser multiple-input-multiple output (MU-MIMO) algorithms, some antennas of BS or UEs may neither transmit nor receive signals due to the long distance or unexpected damages. Therefore, the BS cannot obtain the channel state information (CSI) from/to these antennas. Without these CSI, the performance of algorithm is degraded. We call this effect as ‘broken antenna effect...
In conventional multi-user MIMO systems, Shannon capacity has been used mostly as the performance measure for user selection. In this paper, we propose two new MIMO scheduling techniques based on BER instead of capacity as the performance measure for rate maximization with target BER. One of the key contributions of this paper is to use BER instead of capacity as the user selection metric, and another...
This paper presents indoor experimental results on an implemented real-time downlink multiuser multiple-input multiple-output (DL-MU-MIMO) transceiver for next generation wireless LAN systems. In the transceiver, channel state information (CSI) is estimated at each station (STA) and fed back to an access point (AP) on a real-time basis. At the AP, transmit beamforming weight for DL-MU-MIMO transmission...
Bit and power loading schemes for a single-user multiple-input multiple-output channel using a minimum mean-square error receiver are proposed. Such schemes are derived without the benefit of instantaneous channel state information (CSI) at the transmitter, on the basis of only statistical CSI. They exploit the relationships between the average bit error probability at the receiver and the power allocation...
Optimizing energy efficiency (EE) for the MIMO broadcasting channels (BC) is considered in this paper, where a practical power model is taken into account. Although the EE of the MIMO BC is non-concave, we reformulate it as a quasiconcave function based on the uplink-downlink duality. After that, an energy efficient iterative waterfilling scheme is proposed based on the block-coordinate ascent algorithm...
This paper proposes a novel clipping and filtering method employing transmit power control to improve the bit error rate (BER) performance in MIMO-OFDM transmission. The feature of the proposed approach is to perform the transmit power control before clipping and filtering to alleviate the BER degradation caused by clipping and filtering. Since the transmit power control to satisfy maximum signal-to-noise-plus-distortion...
A new space-time block code (STBC) is presented for distributed 4 × 2 multiple-input multiple-output (MIMO) systems. A 2 × 2 full-rate full-diversity (FR-FD) low complexity space-time code, presented by Sezginer and Sari, is employed for two distributed links. Alamouti STBC is applied over the two links to obtain a double layer space-time block code (DLSTBC) providing full diversity in a distributed...
We propose a packet delayed lattice reduction aided MIMO detection for 802.1 1n system. Lattice reduction algorithms are iterative in nature that results in long latency. In high throughput systems like 802.11n, reduction of latency via parallelization causes high hardware complexity. Without parallelization, the receiver needs to buffer the incoming data until the lattice reduction finishes. Depending...
A low-complexity detection algorithm is proposed for Multiple-Input Multiple-Output (MIMO) systems with many transmit and receive antennas. We involve QR Decomposition (QRD) to triangularize the effective MIMO channel matrix so that several MIMO sub-systems can be individually established, which allow detecting several (possibly overlapping) groups of data streams separately. This method is referred...
In this paper, we propose a novel whitening-rotation (WR) based semi-blind (SB) scheme for frequency-selective channel estimation in multiple-input multiple-output (MIMO) multi-carrier (MC) CDMA systems. This scheme is based on a low complexity multi-path multi-carrier decorrelator (MMD) receiver structure developed for the MIMO MC-CDMA system. It is shown that the MMD based receiver naturally enables...
This paper addresses the problem of fractional timing offset and channel estimation in Multiple input Multiple output orthogonal frequency division multiplexing (MIMO OFDM) systems. The estimators have been derived assuming a flat fading channel and using the maximum likelihood criterion. Closed form Cramer Rao bound (CRB) expressions for fractional timing offset and channel response are also derived...
In this paper, the truncated singular value decomposition expectation-maximization (TSVD-EM) based channel estimation on single transmit antenna transmission is extended to transmit diversity transmission. Particular attention is given to Long Term Evolution (LTE) systems. In order to obtain the received symbols for each transmit antenna, an approximation is proposed by using the soft symbols and...
In this paper, we propose a cooperative particle swarm optimization (CPSO) based channel estimation/equalization scheme for multiple-input multiple-output zero-padded single-carrier (MIMO-ZPSC) systems with large dimensions in frequency selective channels. We estimate the channel state information at the receiver in time domain using a PSO based algorithm during training phase. Using the estimated...
In this work, the problem of receiver design for phase noise estimation and data detection in the presence of oscillator phase noise in a point-to-point multiple-input multiple-output (MIMO) system is addressed. First, we discuss some interesting and challenging aspects in receiver design for MIMO systems in the presence of Wiener phase noise. Then, using the variational Bayesian (VB) framework, a...
We investigate simplified, yet mismatched, receivers for SC-FDMA MIMO transmission currently employed in the 3GPP LTE-Advanced uplink. The receivers are based on frequency domain equalization and time domain detection. Rates achievable by those mismatched receivers with arbitrary input alphabets are derived in terms of generalized mutual information. The results allow to compare the impact of certain...
In the next generation cellular systems, such as LTE-A (Release 10 and beyond), relay node (RN) deployment has been adopted due to its potentials in enlarging coverage and increasing system throughput, even with primitive relaying functionalities. For example, in LTE-A Release 10 only Type-I (non-transparent) RNs are considered wherein no cooperative transmission to the Donor evolved-NodeBs (DeNBs)...
We design a multiple-access relay network with multiple sources and relays via network coded cooperation where the radio resources in three dimensions: time, space and user are jointly optimized. For this, we derive the decoding error probability of two MIMO modes and develop an optimal MIMO mode selection and power allocation strategy for multiple sources and relays, so as to minimize the decoding...
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