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An efficient full-rate linear dispersion (LD) code is designed over correlated Rayleigh fading channel. This code is suitable for mobile station in LTE-Advanced system where a code with two antennas and three time slots is required and the orthogonal Alamouti code can not be appUed. For this purpose, we first derive a closed-form formula for the ergodic achievable information rate of an LD coded multi-input...
We study and analyze coverage region for MIMO amplify-and-forward (AF) relay network. We consider the network geometry in which L relays are placed uniformly around the source, and assume that there is no direct link between source and destination. We analyze desired transmission rate with the purpose of maximizing coverage region. Using Monte Carlo simulations the impact of number of transceiver...
In this paper, performance of a Turbo Code (TC) and Vertical Bell Laboratories Layered Space Time (VBLAST) encoded wireless link is evaluated in the presence of Rayleigh fading for Multiple-Input Multiple-Output (MIMO) system. Turbo encoded bits are modulated using QPSK or 16 QAM or 64 QAM modulator and modulated data are further encoded using VBLAST and then split into n streams which are simultaneously...
In this paper, an order reduction maximum likelihood (OR-ML) algorithm for spatial modulation systems is proposed to reduce the receiver complexity. The proposed algorithm relies on a smaller order neighbourhood constellation which is relative to the conventional mapping constellation, where the active transmitting antenna indices or the possible quadrant transmission symbols locate in is obtained...
Long Term Evolution (LTE) is a standard for wireless communication of high speed data for mobile phones and data terminals. LTE is capable of delivering large data rate on the order of several megabits per second, which is even larger than the current 3G systems. This is very challenging as the wireless networks are subjected to interference, multipath and poor propagation channel characteristics...
In this paper we describe and simulate an accurate Bit Error Rate (BER) estimator for a chip level Wiener equalizer and combined equalizer/interference canceller for employment with the CDMA MIMO High Speed Downlink Packet Access (HSDPA) feature of the Third Generation Partnership Project (3GPP). In the 2 × 2 MIMO system two data streams may be transmitted in the downlink to each user equipment (UE)...
In this paper, we elaborated on a new interference alignment technique for downlink multi-user system in a MIMO-X channel with multiple antennas. We considered two transmitters, each equipped with M antennas, and L users, each equipped with K antennas. Here, we consider a MIMO-X scenario that some users are receiving transmissions from both transmitters. The proposed approach is focused on rank-1...
In this paper, we present a method which jointly performs robust channel estimation and signal detection over rank-deficient MIMO links. This technique achieves an excellent estimation of the channel matrix by using all detected symbols within a data frame. Symbol detection is achieved by means of a sphere decoding algorithm. The proposed scheme is equivalent to having the training preamble occupy...
Sparse space codes (SSC) are proposed as a novel transmission scheme for an under-determined MIMO channel. Each SSC codeword is a sparse vector of the size of the number of transmit antennas. The information is imparted through: (i) uncertainty in the positions of non-zero elements, and (ii) uncertainty in the symbol-space of non-zero elements. Basis-pursuit (BPD) and LASSO detectors are used with...
A phase rotation precoding is proposed for MIMO system to reduce interference caused by transmit correlation. The optimal rotation phases are designed based on maximize the infimum of the set of effective error vectors' norm. Simulation results show the validity of the proposed scheme, which, in the same conditions, improves reliability compared to the other phase rotation precoding scheme.
In this paper, we present an improved DFT-based channel estimation method. The conventional discrete Fourier transform(DFT)-based approach will cause energy leakage in multipath channel with non-sample-spaced time delays. The improved method uses symmetric property to extend the LS estimate in frequency domain, and calculates the changing rate of the leakage energy, and selects useful paths by the...
Block diagonalization (BD) is a downlink precoding technique that cancels inter-user interference in downlink multiuser MIMO systems. But the number of simultaneously supportable receive antennas is limited by the number of base station transmit antennas for multiuser MIMO systems with BD. When a large number of receive antennas exist, the base station can select a subset of receive antennas for each...
This paper investigates the implementation scenario of Space Division Multiple Access(SDMA) which is a notable application of Multiple Input Multiple Output(MIMO) system. SDMA is one of the most promising techniques aiming at solving the capacity problem of wireless communication systems and achieving higher spectral efficiency, depending on multiplexing signals based on their spatial signature. This...
We address the main technical challenge encountered in the practical implementations of full-duplex MIMO relays, i.e., how to mitigate efficiently the self-interference that loops back from the relays transmit antenna array to its receive antenna array. In particular, we consider spatial-domain suppression using optimal eigenbeamforming that minimizes the power of the residual self-interference signal...
A number of peak-to-average power ratio (PAPR) reduction techniques have been proposed for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems; however, most of them involve very high computational complexity and are not applicable to MIMO-OFDM systems with space frequency block coding (SFBC). In this paper, we propose a low-complexity PAPR reduction scheme...
In this paper, we propose a codebook construction method for multiple-input multiple-output (MIMO) beamforming systems operating under the per-antenna power constraint (PAPC). Under the PAPC which limits the individual power of each transmit antenna, it is known that only phase steering information is required to form the optimal beamforming vector at the transmitter. For systems with non-reciprocal...
This paper presents results from a novel OFDMA multi-cell mobile broadband system level simulator. The tool is used to statistically characterize uplink and downlink inter-cell interference. Without suitable interference management, multi-billion dollar networks can collapse under the strain of heavy traffic loads. Fully loaded interference studies cannot be performed on the network until it has been...
This paper carries out the first-ever study of the feasibility of using chaos shift keying (CSK) in a Multiple-Input, Multiple-Output (MIMO) channel. To that end, an Alamouti space time code scheme is combined with the CSK system for 2 transmit and 2 receiver antennas. Once the design of CSK-MIMO system is presented, the performance of the proposed system is analyzed in a mono-user case. An exact...
The virtual MIMO (V-MIMO) and coordinated multipoint transmission (CoMP) are adopted by the LTE system to extend the uplink spectral efficiency. V-MIMO makes use of spatial multiplexing to increase system throughput while CoMP by means of mitigating inter cell interference (ICI) significantly achieve the same effect. In this paper, we present an orthogonality based proportional fair scheduling (OPF)...
MIMO, OFDMA and cooperative relaying are the key technologies in future wireless communication systems. However, under the usage of these technologies, resource allocation becomes a more crucial and challenging task. In multi-user MIMO-OFDMA relay-enhanced cellular networks, we formulate the optimal instantaneous resource allocation problem including user group selection, path selection, power allocation,...
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