Performance analysis of WDM MIMO RoFSO links for 5G applications

To increase the transmission rate without bandwidth expansion, multiple-input multiple-output (MIMO) technique has been attracting much attention. When MIMO technique is applied to a cellular system, the MIMO channel capacity is affected by the interference from neighboring co-channel cells. In this paper, we evaluate the outage probability of MIMO downlink channel capacity in a cellular system, taking into account the frequency-reuse factor, path loss exponent, standard deviation of shadowing loss, and base station (BS) transmit power. We discuss about the cellular channel capacity. Furthermore, we compare the cellular MIMO channel capacity with those of other multi-antenna transmission techniques such as space time block coded multiple-input single-output (STBC-MISO) and single-input multiple-output (SIMO). We show that the optimum frequency reuse factor is 3 irrespective of type of multi-antenna transmission scheme for the outage probability of 10 %. We also show that the cellular MIMO channel capacity is always higher than those of SIMO and MISO.

Free Space Optical (FSO) communication has evolved as a feasible technique for wireless implementations which offers higher bandwidth capacities over various wavelengths and refers to the transmission of modulated visible beams through atmosphere in order to communicate. Wavelength Division Multiplexing (WDM) is a technology that multiplexes numerous carrier signals onto single fiber using nonidentical wavelengths and enables the efficiency of bandwidth and expanded data rate. Multiple Input Multiple Output (MIMO) is implemented to improve the quality and performance of free space optical communication in various atmospheric conditions. In this paper, a WDM-based FSO communication system is being implemented that benefits from MIMO which receives multiple copies of the signal at receiver that are independent and analyzed for various streams of data in MIMO i.e. 2 × 2, 4 × 4, 8 × 8. Various factors like BER, Quality Factor are analyzed for the WDM-based FSO communication with MIMO using the OptiSystem for various data streams of MIMO under different atmospheric conditions.

Over the last few years, the concept of multiple input multiple output (MIMO) has become a popular area of research in the field of wireless communications with the aim of delivering increased data rates. However, to date, MIMO research has focussed primarily on communications within the VHF, UHF and SHF bands (and above). Very little experimental or modelling research has been conducted in the area of exploiting MIMO techniques within the HF radio band. This paper describes some of the preliminary experimental work that has been carried out in order to investigate the feasibility of implementing MIMO techniques within the HF band.

Visible Light Communication (VLC) has emerged as a powerful technique for wireless communication systems. Providing high data rate and increasing capacity are the major problems in VLC. Recent evidence suggests that Multiple Input Multiple Output (MIMO) technique can offers improved data rates and increased link range. This paper describes the design and implementation of visible light communication system in indoor environment exploring the benefits of MIMO. The specific objective of this research was to implement a 4×4 Multiple Input (LEDs) Multiple Output (photodetectors)-VLC communication system, where a 16 white power LEDs in four arrays are setting up at transmitter and four RX modules are setting up at receiver side without the need for additional power or bandwidth as well as analyze a mathematical model for a VLC- 4×4 MIMO with different modes such as the suitable angles to cover the entire room. The research designs practically an electronic circuit for the transmitter and receiver with inexpensive components. The power distribution of different propagation modes is calculated for Single Input Single Output (SISO) and MIMO channels in typical room dimensions. The results in this paper indicate that the power is distributed uniformly for entire room when implemented VLC-MIMO as compared to VLC-SISO. Furthermore, a 4×4 MIMO implementing VLC is compared in term of BER vs. SINR with SISO communication system for both Line of Sight (LOS) and Non Line of Sight (NLOS) propagation modes. Comparing the two results of LOS and NLOS, it can be seen that a 4×4 MIMO implementing VLC for LOS perform better than the same system with NLOS due to decreasing in the received power resulted from the multipath effect.

Multiple-Input Multiple-Output (MIMO) technologies utilize multiple antennas at the transceivers and enable enhanced diversity or multiplexing gain. The first implementations of MIMO technology appeared in cellular communication and Wi-Fi systems. One of the main problems with early MIMO systems is their limited performance in meeting the requirements of next generation communication systems. Specifically, the parameters like peak data rates, spectrum efficiency and energy efficiency constraints cannot be met with existing MIMO architectures. Hence, early MIMO techniques evolved to massive MIMO (mMIMO) type of communication as the number of antennas at both transmitters and receivers increased. Included in 5G New Radio standard, mMIMO enabled an increase the spectral efficiency and coverage compared with earlier MIMO techniques. Nowadays, there exists an ever-increasing interest in the application of advanced MIMO technologies in 6G networks. These applications include ultra massive MIMO (mMIMO), holographic MIMO and intelligent reflecting surface (IRS) assisted MIMO. These new advanced MIMO techniques either employ larger number of antennas or extremely large aperture arrays compared with mMIMO and are named as extremely large-scale MIMO. This paper presents a detailed overview of all these techniques. Joint design of wireless communication and radar sensing, named as integrated sensing and communication (ISAC) as well, has shown to improve spectrum efficiency and reduce power consumption. Recent novel research on ISAC exploits the application of MIMO technology specifically in joint communication and radar sensing (JCS) systems. In this aspect, the other objective of this work is to exploit MIMO communication and MIMO radar coexistence. After summarizing the current state of the art on MIMO radar systems, this paper exploits joint application of advanced MIMO communication and radar sensing. Finally, it aims to offer a perspective on future research directions and the potential of overall MIMO systems discussed in the paper.

In order to satisfy constantly increasing user demands, in process of transition towards LTE (Long Term Evolution) mobile networks of 4th generation, for 3G UMTS networks potential solution is exploitation of multi-antenna MIMO (Multiple Input Multiple Output) systems, which provide increase in both capacity and reliability. This paper puts an effort to provide a link between link-level and system-level gains introduced by multi-antenna techniques in UMTS systems. Coverage, capacity and achievable data rates are evaluated and presented for Alamouti scheme, TxAA and D-TxAA. Radio mobile planning tool is used for illustration of coverage improvement achieved by implementation of several multi-antenna techniques. Considering system-level gains, it is seen that implementation of MIMO techniques yields larger service area and/or increase in capacity and available data rates maintaining the same bandwidth. Results presented in this paper help making a clear picture of achievable gains, employment costs and answering the question: Should mobile operators invest in upgrading their 3G networks with MIMO techniques and is that investment justified, considering achievable improvements.

Attracting increasing attention in recent years, the Free Space Optics (FSO) technology has been recognized as a cost-effective wireless access technology for multi-Gigabit rate wireless networks. Radio over Free Space Optics (RoFSO) provides a promising enhancement to optical fiber systems. In an RoFSO system using wavelength-division multiplexing (WDM), it is possible to concurrently transmit multiple data streams consisting of various wireless services at very high rate. In this paper, we develop power allocation schemes for adaptive WDM transmissions to combat the effect of weather turbulence in FSO networks. The problem of optical power allocation under power budget and eye safety constraints is investigated for adaptive WDM transmission in RoFSO networks. Simulation results show that WDM RoFSO can support high data rates even over long distance or under bad weather conditions with an adequate system design.

Background: As the multimedia service develops and the transmission rate in terrestrial communication systems increases rapidly, satellite communication needs to improve the transmission rate and throughput. Multiple Input Multiple Output (MIMO) techniques can increase the system capacity significantly by introducing the space dimension, as the system bandwidth remains the same. Therefore, utilization of MIMO for satellite communications to increase the capacity is an important research topic. So MIMO techniques for multibeam satellite communications are researched in the dissertation. Objective: The goal of this work is improving the capacity of the satellite system. Multi-beam and dual-polarized technologies are applied to a satellite system to improve the capacity further. Methods: In this paper, we first introduce a multi-beam dual-polarized satellite multi-put and multiout (MBDP-S-MIMO) system which combines the full frequency multiplexing and dual-polarization technologies. Then the system model and channel model are first constructed. At last, to improve the capacity further, BD and BD-ZF precoding algorithms are applied to MBDP-S-MIMO and their performance is verified by simulation. Results: Simulation results show the performance of the BD precoding algorithm gets better with the growth of the XPD at the receiver and is almost not affected by the growth of the channel polarization correlation coefficient. In addition, with the growth of the users’ speed, the performance becomes worse. Conclusion: The multi-beam dual-polarized satellite MIMO system has high capacity, and it has certain application prospects for satellite communication.

Multiple input multiple output (MIMO) systems increase the channel capacity within the limited frequency band. MIMO techniques can be combined with orthogonal frequency division multiplexing (OFDM), which is known to combat frequency selectivity in wireless channels. When channel state information (CSI) is available at the transmitter, the eigenvector beamforming method is well known to achieve the maximum channel capacity. However, the performance of eigenvector beamforming, which employs both modulation and forward error correction schemes, is not very well understood. In this paper, we evaluate the channel capacity and the frequency utilization of an eigenvector beamforming method in an actual indoor environment using an 8times4 MIMO-OFDM testbed that we developed. The experiment results indicate that the transmission bit rate increases offered by the eigenvector beamforming method in 4times4 MIMO and 8times4 MIMO channels are 3.83 fold and 4.90 fold larger than the performance of conventional transmission in SISO channel respectively and these ratios are larger than the increases in the channel capacity

An orthogonal frequency division multiplexed-radio over free space optics (OFDM-RoFSO) communication system with dual multiplexing is proposed. Eight input data streams are transmitted simultaneously by using wavelength division multiplexing (WDM) at level 1 and polarization division multiplexing (PDM) at level 2. Input data streams 1–4 and 5–8 are assigned with same set of carrier frequencies i.e. 193.1 THz, 193.3 THz, 193.5 THz and 193.7 THz and separate polarization levels (X and Y polarized) before transmitting through RoFSO link. A total data rate of 160 Gbps (4 × 2 × 20 Gbps) is achieved in this design. With proposed system, channel performance is evaluated under the influence of atmospheric attenuation and turbulence conditions while measuring system BER, Q-factor, SNR and received power etc. The effect of channel crosstalk is analysed for WDM-PDM dual multiplexed design while considering single input single output (SISO) and multiple input multiple output (MIMO) FSO configurations. The overall analysis predicts that a higher transmission rate and improved capacity levels can easily be achieved with dual multiplexed system.

Higher order nonlinear systems with prevailing delay have been very challenging in significance with stability and process performance. This paper investigates the performance of a type-2 Mamdani intelligent controller implemented a delay dominant system which is modelled using black box approach identified to be a second order nonlinear model for a dual spherical tank liquid level system (DSTLLS) under LabVIEW environment. The adaptive approach of the intelligent Mamdani-based fuzzy controller proves itself to be very competent compared with the earlier experimented methods that already exist. The performance indices like integrated absolute error (IAE) and integrated squared error (ISE) are also calculated for different varying set point changes of DSTLLS. The response and error reduction efficiency of this method of adaptive type-2 intelligent fuzzy (ATIF) controller has been experimented for different flow configurations of this DSTLLS, like multiple input single output (MISO), multiple input multiple output (MIMO) and single input single output (SISO).

This paper concerns the identification of MISO (multiple inputs single output) Wiener systems. For each input-output path, the linear dynamics are modeled by a set of orthonormal basis functions (OBFs). The static nonlinearity is modeled through a multivariate polynomial. The parameters of the model are the coefficients of this polynomial. In this paper, an identification procedure for SISO (single input single output) Wiener systems is extended towards MISO Wiener systems. The poles of the OBFs are estimated using an extension of the best linear approximation (BLA) towards MIMO (multiple input multiple output) systems. As the number of parameters can increase significantly compared to the SISO case, a parameter reduction step, first developed for the SISO case, is extended in this paper to the MISO case. In each set of OBFs, one OBF is replaced by the BLA of the input-output path corresponding to that set. It is shown that in this way the number of relevantly contributing terms in the multivariate polynomial is significantly reduced. Simulation results show a major reduction of the number of parameters, with only a minor increase in the rms error on the simulated output.

We evaluate the performance of single- and multi-antenna multi-carrier code division multiple access (MC-CDMA) downlink (base station to mobile terminal) systems in multi-cell environments. We first propose a minimum mean square error (MMSE) filter for a single input single output (SISO) MC-CDMA downlink system. Then, we apply it to a SIMO (single input multiple output) system with a conventional turbo coding. Furthermore, we compare the performance of SISO (1 /spl times/ 1) and SIMO (1 /spl times/ 2) MC-CDMA systems with that of a multiple input multiple output (MIMO) (2 /spl times/ 2) system employing space-time turbo coded modulation (STTuCM) in a multi-cell environment with 7 cells by computer simulation. Based on the computer simulation results, it is found that the considered MIMO system can achieve twofold capacity with the same transmission power in the multi-cell environment.

Motivated by the study of the optimization of the quality of service for multiple input multiple output (MIMO) technique in a wireless communication system. The capacity of MIMO channel in independent Rayleigh channels grows linearly as the number of antennas. However, some limitations on the MIMO capacity is due to the correlation between individual sub-channels of the matrix channel. In this paper, we investigate the MIMO channel capacity in correlated channels using a new correlation matrix model. After some mathematical recalls we derive the general upper bound on the MIMO channel capacity. We give the analytical results, which measure the effect of correlation on the MIMO capacity for a proposal model. Then, we use the correlation matrix approach to compute the capacity of MIMO with respect to signal-to-noise (snr) and then predict the numbers of antennas. By fixing the snr variable to a specific value, we extract informations on the optimal numbers of MIMO antennas. Finally, we have given the variation of the MIMO capacity in the limiting case of N rarr infin for our proposal model and the exponential correlation matrix model.

MIMO technique for simultaneous measurement of translational and rotational mobilities