Comparative Analysis of Bit Error Rate and Outage Capacity for MIMO Space Time Trellis Coding

In this paper, we have first given brief introduction to Multiple Inputs Multiple Outputs (MIMO) systems. After that different MIMO models and their capacity is discussed. We have compared bit error rate of different modulation techniques like Phase Shift Keying (PSK), Quadrature Amplitude Modulation i.e. QAM 16, QAM 32, QAM 64 using Space Time Trellis Coding (STTC). The outage capacity and bit error rate of MIMO and MISO have also been compared. The Rank criterion is used for maximizing the rank of transmitting antennas matrix in STTC. The proposed technique increases spatial diversity and coding gain of MIMO channels

Modeling of wide-band MIMO radio channels based on NLoS indoor measurements

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Pattern Reconfigurable Cubic Antenna

International audienceA new single-feed reconfigurable antenna for pattern diversity is presented in this paper. The proposed structure is based on a metallic cubic cavity which radiates through rectangular slots. The pattern reconfiguration is achieved with PIN diode switches by short-circuiting slots in their center. The designed antenna can switch between three different radiation patterns which radiate in a 4π steradian range and can receive any incident field polarizations. A prototype of the antenna, including PIN diodes and operating in the 5 GHz band, has been built to demonstrate the feasibility of the concept. Measurements have been conducted and three-dimensional radiation patterns are provided. Diversity performances are evaluated by calculating the envelope correlation coefficient

MIMO for DVB-NGH, the next generation mobile TV broadcasting

DVB-NGH (Digital Video Broadcasting - Next Generation Handheld) is the next generation technology for mobile TV broadcasting, which has been developed by the DVB project with the most advanced transmission technologies. DVB-NGH is the first broadcasting standard to incorporate multiple-input multiple-output (MIMO) as the key technology to overcome the Shannon limit of single antenna communications. MIMO techniques can be used to improve the robustness of the transmitted signal by exploiting the spatial diversity of the MIMO channel, but also to achieve increased data rates through spatial multiplexing. This article describes the benefits of MIMO that motivated its incorporation in DVB-NGH, reviews the MIMO schemes adopted, and discusses some aspects related to the deployment of MIMO networks in DVB-NGH. The article also provides a feature comparison with the multi-antenna techniques for 3GGP's LTE/LTE-Advanced for cellular networks. Finally, physical layer simulation results calibrated within the DVB-NGH standardization process are provided to illustrate the gain of MIMO for the next generation of mobile TV broadcasting.Vargas Paredero, DE.; Gozálvez Serrano, D.; Gómez Barquero, D.; Cardona Marcet, N. (2013). MIMO for DVB-NGH, the next generation mobile TV broadcasting. IEEE Communications Magazine. 51(7):130-137. doi:10.1109/MCOM.2013.6553689S13013751

Wireless communication for firefighters using dual-polarized textile antennas integrated in their garment

A compact wearable antenna system, completely made out of textile materials for integration into protective garments, is proposed. The system implements combined pattern and polarization diversity to improve the quality of the communication link. The performance of the on-body antenna system, integrated into a firefighter jacket worn by a test person, was investigated in an indoor measurement campaign. Several receiver diversity schemes and different combining techniques were evaluated in terms of bit error rate, signal-to-noise ratio and signal correlations. By comparing them to theoretical results, we demonstrate the reliability of the proposed system and the advantage of using diversity

Methods and criteria for performance analysis of multiantenna systems in mobile communications

Multiple-input multiple-output (MIMO) technique is one of the most promising solutions for increasing reliability and spectral efficiency of the radio connection in future mobile communication systems. The performance potential of MIMO systems is well established from theoretical point of view. However, much effort is still needed in the experimental verification of those systems using realistic antennas and channels. It is widely accepted that the antenna properties are of significant importance regarding the performance of single-input single-output (SISO) systems. However, the effect of the antennas on MIMO systems has not been thoroughly studied. Due to the complexity of MIMO systems, evaluation of MIMO antennas becomes increasingly cumbersome and time-consuming process in comparison to simpler systems. In the first part of this work an advanced antenna evaluation technique called experimental plane-wave based method (EPWBM) is generalized and validated to cover MIMO systems. This work is the extension of the previous work where the method has been used in the analysis of SISO systems. The EPWBM is based on the measured or simulated complex 3-D radiation patterns of the antennas and measured directional radio channel data. The EPWBM simplifies antenna evaluation process in comparison to traditional means since the same channel library can be utilized in the evaluation of several antenna systems without performing the same measurements for each prototype antennas separately. It is verified that the EPWBM is sufficiently reliable in comparing the performance of prototype antennas. In the second part of the work new quality factors for MIMO system evaluation enclosing traditional systems as special cases have been developed. The MIMO channel correlation matrix is formulated so that it reveals the ability of MIMO antenna systems to transfer signal power from a transmitter to a receiver and to utilize parallel spatial channels. It is also verified that correct normalization of the channel matrices is of significant importance in the MIMO antenna evaluation. This approach gives comprehensive framework for MIMO antenna evaluation, which takes into account both realistic antenna and channel properties. In the last part of the work insight into the performance of different antennas in different signal propagation environments is given. The performance of the antennas depends on the signal-to-noise-ratio and on the outage probability level considered. Although MIMO systems are based on the utilization of parallel spatial channels, the capability of the system to transfer signal power plays a significant role especially with small MIMO systems. In the realistic dynamic channels the capacity variation is larger than in the ideal channels, which are based on the identically and independently distributed (iid) channel assumption. Large performance variations occur in the realistic channels with directive antennas, when antennas are rotated in the usage environment, whereas omnidirectional ones are more robust but are difficult to realize in practice. The largest differences between the antennas are found at the low outage probability levels due to different radiation properties of the antennas. The systems with the cross-polarized antennas have smaller eigenvalue dispersion and are more robust in performance for the variations of the channel than the systems with co-polarized antennas. On the other hand, the co-polarized antennas possess better capability to transfer signal power and are more robust in performance for the antenna array orientation. From practical point of view, the dual-polarized antennas seem to be the most feasible candidates to be used in MIMO antenna systems due to compact structure, and indoor seems to be the most suitable for MIMO applications due to typically scatter-rich channel.Multiple-input multiple-output (MIMO) tekniika on yksi lupaavimmista ratkaisuista lisätä radioyhteyden luotettavuutta ja spektritehokkuutta tulevaisuuden matkaviestinjärjestelmissä. MIMO järjestelmien suorituskykypotentiaali on teoreettisesti todistettu. Paljon työtä tarvitaan kuitenkin vielä kokeelliseen järjestelmätestaukseen käyttäen realistisia antenneja ja kanavia. On laajasti hyväksyttyä että antennien ominaisuudet ovat merkityksellisiä single-input single-output (SISO) järjestelmien suorituskyvyn kannalta. Antennien vaikutusta MIMO-järjestelmiin ei ole kuitenkaan perusteellisesti tutkittu. MIMO-järjestelmien lisääntyneestä monimutkaisuudesta johtuen, verrattuna yksinkertaisempiin järjestelmiin, MIMO antennien suorituskyvyn arviointi hankaloituu ja vie enemmän aikaa. Työn ensimmäisessä osassa uusi antennien arviointitekniikka nimeltään kokeellinen tasoaaltoihin perustuva menetelmä (EPWBM) on yleistetty käsittämään MIMO järjestelmät ja sen tarkkuus on arvioitu. Tämä työ on laajennus aikaisempaan työhön jossa menetelmää on käytetty SISO-järjestelmien arviointiin. EPWBM perustuu mitattuihin tai simuloituihin antennien kompleksisiin 3-D suuntakuvioihin ja mitattuun suuntatiedon sisältämään kanavadataan. EPWBM yksinkertaistaa antennin suorituskyvyn arviointia perinteisiin menetelmiin verrattuna, koska sama kanavamittausaineisto voidaan hyödyntää usamman antennisysteemin arvioinnissa tekemättä samoja mittauksia jokaiselle antenniprototyypille erikseen. On osoitettu että EPWBM on suhteellisen luotettava prototyyppiantennien suorituskyvyn vertailussa. Työn toisessa osassa on kehitetty uusia hyvyyslukuja MIMO-järjestelmien suorituskyvyn arviointiin sisältäen perinteiset järjestelmät erikoistapauksina. MIMO-kanavamatriisi esitetään siten että se paljastaa MIMO-antennijärjestelmien kyvyn siirtää signaalitehoa lähettimen ja vastaanottimen välillä ja hyödyntää rinnakkaisia kanavia. On myös todistettu että oikeanlainen kanavamatriisien normalisointi on erittäin merkittävää MIMO-antennivertailussa. Tämä lähestymistapa antaa kattavat puitteet MIMO-antennien suorituskyvyn arviointiin ottaen huomioon todelliset antennien ja kanavan ominaisuudet. Työn viimeisessä osassa annetaan käsitys erilaisten antennien suorituskyvystä erilaisissa signaalin etenemisympäristöissä. Antennien suorituskyky riippuu signaalikohinasuhteesta ja tarkasteltavan signaalin luotettavuustasosta. Vaikka MIMO-järjestelmät perustuvat rinnakkaisten kanavien hyödyntämiseen järjestelmän signaalitehon siirto-ominaisuudet ovat merkittäviä erityisesti pienillä MIMO järjestelmillä. Realistisissa dynaamisissa kanavissa kapasiteetinvaihtelu on suurempaa kuin ideaalisissa kanavissa jotka perustuvat oletukseen että signaalit ovat riippumattomasti ja identtisesti jakautuneita (iid). Suurta suorituskykyn vaihtelua esiintyy realistissa kanavissa suuntaavilla antenneilla, kun antenneja pyöritetään käyttöympäristössä, kun taas ympärisäteilevät antennit olisivat jäykempiä suorituskyvyn kannalta mutta käytännössä vaikeampia toteuttaa. Suuremmat erot antennien välillä on löydettävissä matalalta signaalin luotettavuustasolta johtuen antennien erilaisista säteilyominaisuuksista. Kaksipolarisaatioantennijärjestelmillä on pienempi ominaisarvohaje ja niiden suorituskyky on jäykempi kanavan vaihteluille kuin yksipolarisaatioantennijärjestelmä. Toisaalta yksipolarisaatioantenneilla on paremmat signaalitehon siirto-ominaisuudet ja suorituskyky vaihtelee vähemmän antennin katselusuunnan funktiona. Käytännön näkökulmasta katsoen kaksipolarisaatioantennit näyttävät olevan kaikkein toteuttamiskelpoisin vaihtoehto käytettäväksi MIMO-systeemeissä johtuen niiden kompaktista rakenteesta, ja sisätila näyttää olevan sopivin ympäristö MIMO-sovelluksiin johtuen tyypillisesti sirontarikkaasta kanavasta.reviewe

Reconfigurable Antennas for Beam-Space MIMO Transmission with a Single Radio

MIMO techniques allow remarkable improvements in the reliability and/or transmission rate of wireless communication systems. However, there are several major challenges towards the implementation of conventional MIMO concept in terminals with size, cost, and power constraints. Firstly, insufficient space impedes the design of efficient and decorrelated MIMO antennas. Second, MIMO traditionally demands each antenna to be fed by its own RF chain, which in turn results in greater hardware complexity, larger power consumption, and higher implementation cost. Among all reduced-complexity and antenna-decoupling schemes proposed so far, the so-called beam-space MIMO has attracted a great deal of interest as a potential solution for addressing both problems concurrently. The key idea therein is to engineer the radiation pattern of a single-feed antenna structure for each symbol period, such that multiple independent symbols directly modulate a predefined set of orthogonal virtual patterns in the far-field, therefore allowing true MIMO transmission using a single RF chain and a compact antenna structure. More important in practice, the transmitted information can be retrieved using a conventional MIMO receiver. However, the transformation of this idea into reality entails dealing with various practical aspects that are commonly overlooked in theoretical and conceptual developments. This dissertation explores the beam-space MIMO concept from the perspective of the antenna engineering, and aims at addressing several key issues associated with the actual design and implementation of beam-space MIMO systems. The early developments of beam-space MIMO concerned switched parasitic arrays. However, the requirement of utilizing several physically-separate radiators is inconvenient for practicable implementation in compact portable devices. To solve this problem, a single-radiator load-modulated antenna solution is proposed in this dissertation. Another primary challenge consists in emulating high-order modulation schemes such as PSK with realistic hardware. Here, an efficient beam-space MIMO strategy is developed, which allows transmitting PSK data streams of any modulation order using only purely reactive reconfigurable loads, and without the need for a symbol-rate dynamic matching network. The approach is illustrated by the design and fabrication of a realistic antenna for QPSK signaling. The performance of a beam-space MIMO system which utilizes the fabricated antenna is then investigated through over-the-air experiments, and compared with conventional MIMO in realistic environments. Embedding information in the radiation patterns, beam-space MIMO systems are expected to be inherently prone to multiplexing performance degradation in the presence of external field perturbation. This makes the study of near-field interaction influence on beam-space MIMO distinct from those carried out for the case of conventional systems. This issue is considered for the first time in this dissertation. Moreover, like any reconfigurable system, a beam-space MIMO system may suffer from bandwidth expansion of the transmitted signals. The final part of the work is directed towards this important issue. To reduce out-of-band radiation effect, a solution based on shaping the time-domain response of the reconfigurable components is presented. The studies presented in this thesis constitute a crucial step towards MIMO with simpler and cheaper hardware for real-life terminals