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This paper presents a novel technique to enhance the link performance in satellite network. The technique exploits the location diversity of terminals in the ground segment (stations) and the Multiple Input Multiple Output (MIMO) mathematical frames (also known as `Network MIMO'). In this technique these diverse terminals are linked to a control unit (e.g. the hub) to coordinate the joint transmission\...
This paper proposes a novel three-dimensional (3D) regular-shaped geometry-based stochastic model (RS-GBSM) for non-isotropic multiple-input multiple-output (MIMO) mobile-to-mobile (M2M) Ricean fading channels. The proposed model, combining a two-sphere model and an elliptic-cylinder model, is the first 3D RS-GBSM that has the ability to investigate the impact of the vehicular traffic density (VTD)...
We describe a channel sounding system designed for small outdoor cell (~400 meter radius) wireless channel characterization. We report on a program of path loss measurements using a 2×2 MIMO configuration and data reduction in the frequency range of 5.7-5.75 GHz. The results are based on over 10,000 independent complex frequency responses collected in residential neighborhoods in northern New Jersey...
This paper provides a partial answer to the question: "what is the best angular density of multipath in MIMO channels?" using the size-asymptotic theory of Toeplitz matrices for uniform 2-D and 3-D antenna arrays. A Kronecker-type approximation of the array correlation structure is proposed and used to find the angular densities that completely eliminate correlation between any elements...
In this paper, both a time-domain and a frequency-domain 2 × 2 MIMO channel sounders are presented. The time-domain channel sounder is mainly based on the transmission of Code Division Multiplexed (CDM) signals, modulated by a carrier, which are received and acquired by an oscilloscope. The frequency-domain channel sounder is based on a multiport network analyzer which measures the S21 scattering...
This paper presents a state-space based simulation model for multiple-input and multiple-output (MIMO) channels with spatio-temporal channel correlations due to clustered radio propagation. The scattering clusters are modeled as two-dimensional Cauchy (TDCA) clusters. This renders the joint probability density function (PDF) of angle of arrival (AOA) and angle of departure (AOD) that can be approximated...
In this paper, the sensitivity of the error rate performance of MIMO-OFDM-based practical systems (WiMAX and LTE) to wideband channel properties is investigated. The behavior of the wideband channel is characterized in terms of delay spread (DS) and angular spread (AS). The impacts of DS and AS on the system performance are addressed with both qualitative and quantitative analyses. Two channel models...
The channel capacity of a MIMO telecommunication system depends on different parameters such as the signal-to-noise ratio, the space-time characteristics of the propagation channel, the antenna array geometry and the antenna pattern. However, the propagation channel remains the strongest constraint imposed on designers of new radio air interfaces. Using a MIMO channel model, computer simulations are...
Centralized algorithms for weighted sum rate (WSR) maximization for the K-user frequency-flat MIMO Interference Channel (MIMO IFC) with full channel state information (CSI) are considered. Maximization of WSR is desirable since it allows the system to cover all the rate tuples on the rate region boundary for a given MIMO IFC. First, we propose an iterative algorithm to design optimal linear transmitters...
The IEEE802.11ac task group has started to establish a next-generation WLAN standard. The wider channel of more than 80 MHz achieving over a 1-Gbps data rate is discussed. We have developed an experimental platform consisting of baseband and RF units in a 2×2 MIMO-OFDM system for the wider channel and evaluated its system performance in a field experiment. A MIMO-OFDM transceiver in the baseband unit...
Cooperative communication exploits the broadcast nature of wireless channel and uses relay nodes to provide better reliability and higher data rates without increasing power and bandwidth. In this paper, the energy analysis of the asynchronous polarized cooperative (APC) scheme is performed. APC employs multiple antennas at the relay and destination nodes to achieve full duplex amplify-and-forward...
To obtain full benefits of the Alamouti space-time code design on a time-varying acoustic channel, the channel variation is decoupled into two parts: the gain, which is assumed to be constant over an Alamouti pair (two consecutive OFDM blocks), and the phase, which is not restricted in this manner, but allowed to vary from one block to another in a piecewise linear fashion. Under this model, the receiver...
By combining two different system technologies of optical polarization division multiplexing and wireless multiple-input, multiple-output spatial multiplexing, we have successfully demonstrated 2-Gb/s or 5-Gb/s wireless signal transmission over a 60-GHz wireless channel with a doubled spectral efficiency.
Multi-user MIMO systems are in principle capable of an overall multiplexing gain given by the minimum of the number of base station antennas and the total number of antennas at all mobiles, assuming an uncorrelated Rayleigh channel for all users. This paper considers the multiplexing gain available in practice for a finite scattering channel, where a finite number of scatterers occur for each user,...
How to reduce interference between terminals and control side lobe have become hot spots in 4G communication research. In this paper, the beam forming algorithm based on MIMO array with Particle Swarm Optimization (PSO) is proposed to improve modulation waveform and adaptability, furthermore, side lobe suppression is achieved. Because PSO is used to deal with the adaptive beam forming, the algorithm...
In order to efficiently use the common channel resources in multi-user multiple-input and multiple-output (MIMO) systems, an independent component based multiple access (ICMA) scheme is introduced. In ICMA, the signals generated by different users are distinguished only from their independence, where neither non-interfering subchannels nor orthogonality constraints are needed. The scheme is based...
The sphere decoding algorithm for signal transmitted on multiple antennas channel is considered. In this paper, the preprocessing stage is analyzed in order to seek a reduced complexity and some improvements are made to enhance the performance. The computer simulation results show that the improved algorithm by applying Pohst Enumeration with selected initial radius is more efficient than that by...
We investigate how accurate Kronecker model is compared to Spatial Channel Model (SCM) for MIMO link layer simulations. The simulation results show that Kronecker model is a good approximation for MIMO in link layer simulations compared to SCM.
MIMO communication is a core technology for wireless systems. This work presents an improved fixed complexity detection technique for underdetermined and overdetermined MIMO systems, based on a low complexity, diversity optimal, incremental channel partition. This new algorithm also employs a new efficient tree search implementation of the precancellation step. Because of these improvements, this...
In this paper, we present a 3-D MIMO channel model for wideband communication based on the geometric scattering channel model. The space-time-delay correlation is also derived and presented in the case of non-isotropic scattering distribution. We are interested in two MIMO array systems: uni-polarized antenna array and bi-polarized antenna array. For the bi-polarized MIMO systems, the polarizations...
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