A volatile real exchange rate and high unemployment rate is a growing concern in South Africa, therefore the right macroeconomic policy is required. The challenge is to find stability in the real exchange rate paired with a low inflation rate, both of which are necessary to promote long term economic growth, which in turn creates more job opportunities. This study analyses the impact of the exchange rate on unemployment in South Africa by considering quarterly data for the period 2003 to 2013. In this study, the macroeconomic transmission channel is divided into two transmission paths, imports and exports. These find their roots in the Phillips curve and the Keynesian theory on unemployment respectively. The vector error correction model (VECM), together with an analysis of the impulse response functions and variance decompositions, are implemented to determine the short and long run impacts of the exchange rate on unemployment. After the completion of a variety of specifications, estimations and tests, both macroeconomic transmission paths revealed in the empirical analysis that the real exchange rate has a significant impact on unemployment. In the imports transmission path, the real exchange rate, imports and the CPI have significant long term relationships with unemployment. Furthermore, the exports transmission path found significant short term relations with unemployment in considering the real exchange rate, exports and economic growth. The impulse responses in both transmission paths indicated that a shock in the exchange rate will have a significant effect on unemployment in the short run. Similar results were found with the variance decomposition. In the import transmission path, movements in the real exchange rate explained an increasing portion of the variance in unemployment. Alternatively, in the export transmission path the real exchange rate and exports explained an increasing portion of the variance. The evidence therefore suggests that South Africa should focus more on stabilising the exchange rate, since fluctuations in unemployment are a result of shocks in the real exchange rate, following the macroeconomic transmission channels discussed. / MCom (Economics)--North-West University, Vaal Triangle Campus, 2015

A volatile real exchange rate and high unemployment rate is a growing concern in South Africa, therefore the right macroeconomic policy is required. The challenge is to find stability in the real exchange rate paired with a low inflation rate, both of which are necessary to promote long term economic growth, which in turn creates more job opportunities. This study analyses the impact of the exchange rate on unemployment in South Africa by considering quarterly data for the period 2003 to 2013. In this study, the macroeconomic transmission channel is divided into two transmission paths, imports and exports. These find their roots in the Phillips curve and the Keynesian theory on unemployment respectively. The vector error correction model (VECM), together with an analysis of the impulse response functions and variance decompositions, are implemented to determine the short and long run impacts of the exchange rate on unemployment. After the completion of a variety of specifications, estimations and tests, both macroeconomic transmission paths revealed in the empirical analysis that the real exchange rate has a significant impact on unemployment. In the imports transmission path, the real exchange rate, imports and the CPI have significant long term relationships with unemployment. Furthermore, the exports transmission path found significant short term relations with unemployment in considering the real exchange rate, exports and economic growth. The impulse responses in both transmission paths indicated that a shock in the exchange rate will have a significant effect on unemployment in the short run. Similar results were found with the variance decomposition. In the import transmission path, movements in the real exchange rate explained an increasing portion of the variance in unemployment. Alternatively, in the export transmission path the real exchange rate and exports explained an increasing portion of the variance. The evidence therefore suggests that South Africa should focus more on stabilising the exchange rate, since fluctuations in unemployment are a result of shocks in the real exchange rate, following the macroeconomic transmission channels discussed. / MCom (Economics)--North-West University, Vaal Triangle Campus, 2015

In this paper we compare the transmission of a conventional monetary policy shock with that of an unexpected decrease in the term spread, which mirrors quantitative easing. Employing a time-varying vector autoregression with stochastic volatility, our results are two-fold: First, the spread shock works mainly through a boost to consumer wealth growth, while a conventional monetary policy shock affects real output growth via a broad credit / bank lending channel. Second, both shocks exhibit a distinct pattern over our sample period. More specifically, we find small output effects of a conventional monetary policy shock during the period of the global financial crisis and stronger effects in its aftermath. This might imply that when the central bank has left the policy rate unaltered for an extended period of time, a policy surprise might boost output particularly strongly. By contrast, the spread shock has affected output growth most strongly during the period of the global financial crisis and less so thereafter. This might point to diminishing effects of large scale asset purchase programs. (authors' abstrct) / Series: Department of Economics Working Paper Series

The semestral project deals with characteristics and theory of CDMA, OFDM and VSFOFCDM systems. As comparison and evaluation of these systems as transmission channel is being done for Matlab.

Questa tesi contiene tre saggi di teoria macroeconomica. Il primo capitolo presenta una rassegna dei modelli monetari con agenti eterogenei e include una valutazione dei costi dell’inflazione in termini di welfare per agenti con reddito e ricchezza eterogenei. Il secondo capitolo studia le interazioni tra due canali di trasmissione della politica monetaria che emergono in presenza di eterogeneità: il canale del debito nominale e il canale della tassa da inflazione. Il terzo capitolo studia le relazioni tra le aspettative di crescita del reddito e gli episodi di default su debito sovrano. Questo saggio mostra come introducendo un meccanismo di apprendimento del processo stocastico che determina la sostenibilità del debito sia possibile generare una significativa volatilità del debito e riprodurre una frequenza di default empiricamente plausibile. / This thesis presents three essays in macroeconomic theory. The first chapter surveys monetary models with heterogeneous agents and contains an evaluation of heterogeneous welfare costs of inflation when agents have different income and wealth levels. The second chapter studies the interactions between two transmission channels of monetary policy that arise because of heterogeneity: the nominal debt channel and the inflation-tax net worth channel. The third chapter studies the relations between expectations of future output growth of a small open economy and sovereign defaults. This essay shows that learning of the stochastic process that drives debt sustainability induces significant debt volatility and an empirically plausible default frequency.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-04-20T22:42:49Z No. of bitstreams: 1 RAPHAEL TAVARES DE ALENCAR - DISSERTAÇÃO PPGEE 2014..pdf: 1279047 bytes, checksum: 21e02690d9f7fa6020cc8bc9de97b124 (MD5) / Made available in DSpace on 2018-04-20T22:42:49Z (GMT). No. of bitstreams: 1 RAPHAEL TAVARES DE ALENCAR - DISSERTAÇÃO PPGEE 2014..pdf: 1279047 bytes, checksum: 21e02690d9f7fa6020cc8bc9de97b124 (MD5) Previous issue date: 2014-08 / O canal sem fio tem características de desvanecimento devido ao multipercurso, visto que há reflexões e espalhamentos ao longo do caminho percorrido pelo sinal. O desvanecimento é considerado uma das principais causas de degradação do desempenho em um sistema de comunicações móveis, visto que depende fortemente do canal em que se propaga o sinal transmitido. A diversidade de modulação é uma técnica eficiente em termos de utilização de banda de frequência, que consiste na rotação da constelação do sinal digital transmitido associado ao entrelaçamento das componentes de modulação em fase e em quadratura da constelação do sinal. O objetivo da diversidade em modulação é mitigar os efeitos do desvanecimento em comunicações sem fio. Esta dissertação aborda o estudo da diversidade de modulação no cenário de múltiplos raios de propagação Osresultadosapresentamsimulaçõesdecenárioscom múltiplos raios, isto é, o sinal é transmitido por múltiplos percursos, cada um associado a um fator de desvanecimento e um atraso aleatórios. São feitas comparações entre as taxas de erros para oito cenários com e sem interferência intersimbólica, de um a seis raios, com e sem linha de visada, para os esquemas de modulação digital 4-PSK e 8-PSK. São apresentadas as comparações entre os resultados de taxas de erros com e sem o uso da técnica de diversidade de modulação, com a intenção de avaliar o ganho desta técnica nestes cenários. Também é feita uma análise para obter o ângulo de rotação ótimo para as constelações mencionadas, considerando diferentes cenários de multipercurso. Para tanto, são empregados os conceitos de esquemas de modulação digital, múltiplos percursos, distribuições de probabilidade, canais de comunicação e técnicas de diversidade. / The wireless channel has characteristics of multipath fading,due to reflections and scattering that the signal suffers over the propagation path. Fading is considered one of the main causes of performance degradation of a mobile communications system, as it strongly depends on the channel through which the signal is transmitted. Modulation diversity is a bandwidth-efficient technique that consist on the rotation of the digital signal constellation. assiciated with the interleaving of the in-phase and quadrature modulation components. The objective of the modulation diversity technique is to mitigate the effects of fading in wireless communications The results present simulations of multipath scenarios, that is, the signal is transmitted through multiple channels, each one associated with a stochastic fading factor and random delay Biterrorratesareevaluatedandcomparedforforeightdifferentscenarioswithandwithout intersymbolicinterference,fromonetosixpaths,withandwithoutlineofsight,for4-PSKand 8-PSKdigitalmodulationschemes. Transmissionbiterrorratevalues,withandwithouttheuse ofmodulationdiversityarecompared,astoevaluatethegainofthisdiversitytechniqueforsuch scenarios. Also, an analysis is performed to obtain the optimum rotation angle for the mentioned constellations, considering the different multipath scenarios. In this regard, concepts of digital modulation schemes, multiple paths, probability distributions, communication channels and diversity techniques are used.

The aim of this master´s thesis is an explanation of the problem of optical access networks with wavelength division multiplex, main purpose is to demonstrate the difference between simulation and real measurement. The thesis is divided into several basic thematic areas. At the beginning of thesis is outlined the basic division of multiplexing system, there are discussed the basic solutions of wavelength multiplexes and their possible combinations. The next chapter deals with the active elements, which are an essential part of xWDM systems such as optical lasers, detectors and amplifiers. The following chapter is focused on the passive elements, especially on the passive filters, which form a key part of the wavelength multiplex. Methods of measurement C/DWDM networks are discussed in the next part of thesis. The next chapter describes the topology used by active and passive optical networks. Penultimate part of this thesis consists of designs simulated models PON and WDM-PON networks and comparing their transmission parameters. The final part presents the results of practical measurements of experimental optical access network with wavelength division multiplex, the results are simultaneously compared with results of simulations.

Master's thesis compares the standard for digital terrestrial television broadcasting of the first generation DVB-T/H and the second generation DVB-T2 with particular emphasis on the modulator, a security channel interference, the signal from the transmitting environment itself and the modulation signal. The following description of specific models of transmission channels for fixed, portable and mobile reception of digital terrestrial signal. Comparison with the particular relates of the transmission parameters for different types of reception of digital terrestrial television with achieving efficiency and effectiveness of transmission at the level of laboratory measurements and computer simulation.

The thesis examines the impact of VoIP transmission channel characteristics on speech parameters. It seeks ways of emulating properties of a selected VoIP transmission channel and creating a network emulation environment. Several scripts have been created in the Matlab development environment and used to modify and divide a continuous recording into parts identical to the original speeches, before passing through the transmission channel. Subsequently a database of speech recordings is created, as affected by selected characteristics - jitter, bandwidth, loss. Within these databases, symptoms are sought as the most evident characteristics of the transmission channel. Using correlation, symptoms are selected that are best suited for automated determination of the properties of transmission channel characteristics such as jitter, loss and bandwidth.

This thesis deals with an analysis of a system called Digital Audio Broadcast and describes its mathematical model created in MATLAB program. In the first part basic blocks of a transmitter and a receiver are analyzed along with their principles. Then different types of transmission channels for static, portable and mobile receivers are described. The second part contains description of the DAB mathematical model itself. Individual blocks are described in the order of the DAB signal path, from the transmitter through the transmission channel to the receiver side. In this part the graphical user interface is also described. In the final part the results of experimental measurements and simulations are presented.