The scrip involves a literature study to determine how the covenant child / teenager is accommodated in the Reformed church today versus his/her actual need. The question is posed: Is the covenant child accommodated in any way in our current format of church liturgy, or not? Globalisation has made such an impact on the youth of today (postmodern youth or Mosaics) that digital technology has become their focus. Has the church adapted to this? The findings in this script show that the Reformed churches are losing particularly the youth because they have not adapted fast enough to this technology and to the cultural change that is evident in the postmodern child / teenager. The study is not only about the child in the church, but what the child looks like (his / her postmodern attitude / lifestyle) that we want in the church service and what change we need to make to the liturgy of the Reformed church in order to accommodate them. During this study it was also very evident that we need to change the way in which we spread the Word, and not the Word itself. The Truth remains the same – the culture, technology, attitudes, communication methods and intellectual and emotional needs change constantly. And the change is happening at such an alarming rate that we cannot ever think that we have reached the perfect solution. Before we have found the answer, it has changed. We therefore need to constantly re-look at our presentation style. This however does not excuse us from making changes. We need to change with the times and much faster than is currently the norm. The study reveals that the Reformed church currently has a mono-perspective of the liturgy. What is needed is a multi-disciplinary approach when we worship God. It is not only about the child in the church, it is about the place of the church service in the child’s life amidst the enormous impact of culture and digital technology that they are faced with everyday. How can we attempt to be relevant if we still preach as we did 100 years ago? Although the majority of the information that is available on this subject comes from America, the writer believes that it is very relevant to the Reformed churches in South Africa. Further study and research will be needed to determine the exact needs of the South African child / teenager and how to address this. / Dissertation (MA (Theology))--University of Pretoria, 2006. / Practical Theology / unrestricted

The purpose of this study is to evaluate the effects and importance of different cross–section representations and energy group structures for steady state and transient analysis. More energy groups may be more accurate, but the calculation becomes much more expensive, hence a balance between accuracy and calculation effort must be find. This study is aimed at comparing a multi–group energy dynamics code, MGT (Multi–group TINTE) with TINTE (TIme Dependent Neutronics and TEmperatures). TINTE’s original version (version 204d) only distinguishes between two energy group structures, namely thermal and fast region with a polynomial reconstruction of cross–sections pre–calculated as a function of different conditions and temperatures. MGT is a TINTE derivative that has been developed, allowing a variable number of broad energy groups. The MGT code will be benchmarked against the OECD PBMR coupled neutronics/thermal hydraulics transient benchmark: the PBMR–400 core design. This comparative study reveals the variations in the results when using two different methods for cross–section generation and multi–group energy structure. Inputs and results received from PBMR (Pty) Ltd. were used to do the comparison. A comparison was done between two–group TINTE and the equivalent two energy groups in MGT as well as between 4, 6 and 8 energy groups in MGT with the different cross–section generation methods, namely inline spectrum– and tabulated cross–section method. The characteristics that are compared are reactor power, moderation– and maximum fuel temperatures and k–effective (only steady state case). This study revealed that a balance between accuracy and calculation effort can be met by using a 4–group energy group structure. A larger part of the available increase in accuracy can be obtained with 4–groups, at the cost of only a small increase in CPU time. The changing of the group structures in the steady state case from 2 to 8 groups has a greater influence on the variation in the results than the cross–section generation method that was used to obtain the results. In the case of a transient calculation, the cross–section generation method has a greater influence on the variation in the results than on the steady state case and has a similar effect to the number of energy groups. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2011.

Worldwide research regarding the movement patterns, heart rate recordings and work–to–rest ratios of rugby union referees is very limited. It is therefore very important to extend research regarding this topic. The first objective of this dissertation was to determine the frequency, duration and intensity of movement patterns and work–to–rest ratio of different refereeing panels of South African Rugby Union referees during match–refereeing at the National Club Rugby Championship in Stellenbosch during 2007. The second objective was to compare the two halves of the match with regard to the frequency, duration and intensity of the different movement patterns and the work–to–rest ratios of various of SARU referees during match–refereeing at the National Club Rugby Championship in Stellenbosch during 2007. The South African Rugby Union referees were monitored during match–refereeing by means of video and heart rate recordings for a total of 16 matches within a week tournament. The frequency and duration of the different movement patterns during both halves of the matches were analysed using a Dartfish TeamPro analysis software package. Heart rates were recorded during the matches to determine the movement pattern intensities of the referees for the duration of each match using a Suunto Team pack heart rate monitoring system. The work–to–rest ratios were determined by comparing the time (in seconds) spent working (lateral movements and sprinting) to the time spent resting (standing still, walking and jogging). The results revealed a moderate practical significant difference (d=0.51) between the mean frequency of jogging movement patterns for the different refereeing panels. A moderate practical significant difference was also found between the mean duration of jogging (d=0.43) and sprinting (d=0.43) movement patterns of different refereeing panels. The mean intensity of the movement patterns by the different refereeing panels showed large practical significant differences between the anaerobic threshold (d=3.68) and sub–threshold (d=1.36) levels and a moderate practical significant difference for the maximal heart rate zones (d=0.43). Both the provincial and contender panel referees had work–to–rest ratios of 1:4 during match–refereeing. In comparing the two halves of rugby match–refereeing, a large practical significant difference was found between the mean frequency of movement pattern values for standing still (d=2.53), walking (d=2.50), jogging (d=2.42), lateral movements (d=2.86) and sprinting (d=1.31) as well as for mean duration of movement pattern values for standing still (d=2.05), lateral movements (d=0.76) and sprinting (d=0.77). Large practical significant difference were found between the time spent in the maximal threshold (d=2.07), anaerobic threshold (d=0.92) and sub–threshold (d=7.90) heart rate zones measured during the two halves of match–refereeing. Average work–to–rest ratios of 1:3.5 and 1:5 were found for the first and second halves of rugby match–refereeing, respectively. The information gained regarding the activity profile of SARU referees could be used to determine the influence of rugby refereeing experience on the movement patterns and work–to–rest ratio of rugby referees. It can also provide information for constructing specific training programmes and drills in the development of rugby match–required fitness standards for referees. A key component of a rugby union referee’s game is positioning. Being in the right place at the right time is vital. The results of this study suggest that movements associated with positioning ? namely standing still, walking and lateral movements are the major components of the game of referees’ movement during match–refereeing. However, further research is required on this topic of research. / Thesis (M.A. (Sport Science))--North-West University, Potchefstroom Campus, 2012.

The purpose of this study is to evaluate the effects and importance of different cross–section representations and energy group structures for steady state and transient analysis. More energy groups may be more accurate, but the calculation becomes much more expensive, hence a balance between accuracy and calculation effort must be find. This study is aimed at comparing a multi–group energy dynamics code, MGT (Multi–group TINTE) with TINTE (TIme Dependent Neutronics and TEmperatures). TINTE’s original version (version 204d) only distinguishes between two energy group structures, namely thermal and fast region with a polynomial reconstruction of cross–sections pre–calculated as a function of different conditions and temperatures. MGT is a TINTE derivative that has been developed, allowing a variable number of broad energy groups. The MGT code will be benchmarked against the OECD PBMR coupled neutronics/thermal hydraulics transient benchmark: the PBMR–400 core design. This comparative study reveals the variations in the results when using two different methods for cross–section generation and multi–group energy structure. Inputs and results received from PBMR (Pty) Ltd. were used to do the comparison. A comparison was done between two–group TINTE and the equivalent two energy groups in MGT as well as between 4, 6 and 8 energy groups in MGT with the different cross–section generation methods, namely inline spectrum– and tabulated cross–section method. The characteristics that are compared are reactor power, moderation– and maximum fuel temperatures and k–effective (only steady state case). This study revealed that a balance between accuracy and calculation effort can be met by using a 4–group energy group structure. A larger part of the available increase in accuracy can be obtained with 4–groups, at the cost of only a small increase in CPU time. The changing of the group structures in the steady state case from 2 to 8 groups has a greater influence on the variation in the results than the cross–section generation method that was used to obtain the results. In the case of a transient calculation, the cross–section generation method has a greater influence on the variation in the results than on the steady state case and has a similar effect to the number of energy groups. / Thesis (M.Ing. (Nuclear Engineering))--North-West University, Potchefstroom Campus, 2011.

Worldwide research regarding the movement patterns, heart rate recordings and work–to–rest ratios of rugby union referees is very limited. It is therefore very important to extend research regarding this topic. The first objective of this dissertation was to determine the frequency, duration and intensity of movement patterns and work–to–rest ratio of different refereeing panels of South African Rugby Union referees during match–refereeing at the National Club Rugby Championship in Stellenbosch during 2007. The second objective was to compare the two halves of the match with regard to the frequency, duration and intensity of the different movement patterns and the work–to–rest ratios of various of SARU referees during match–refereeing at the National Club Rugby Championship in Stellenbosch during 2007. The South African Rugby Union referees were monitored during match–refereeing by means of video and heart rate recordings for a total of 16 matches within a week tournament. The frequency and duration of the different movement patterns during both halves of the matches were analysed using a Dartfish TeamPro analysis software package. Heart rates were recorded during the matches to determine the movement pattern intensities of the referees for the duration of each match using a Suunto Team pack heart rate monitoring system. The work–to–rest ratios were determined by comparing the time (in seconds) spent working (lateral movements and sprinting) to the time spent resting (standing still, walking and jogging). The results revealed a moderate practical significant difference (d=0.51) between the mean frequency of jogging movement patterns for the different refereeing panels. A moderate practical significant difference was also found between the mean duration of jogging (d=0.43) and sprinting (d=0.43) movement patterns of different refereeing panels. The mean intensity of the movement patterns by the different refereeing panels showed large practical significant differences between the anaerobic threshold (d=3.68) and sub–threshold (d=1.36) levels and a moderate practical significant difference for the maximal heart rate zones (d=0.43). Both the provincial and contender panel referees had work–to–rest ratios of 1:4 during match–refereeing. In comparing the two halves of rugby match–refereeing, a large practical significant difference was found between the mean frequency of movement pattern values for standing still (d=2.53), walking (d=2.50), jogging (d=2.42), lateral movements (d=2.86) and sprinting (d=1.31) as well as for mean duration of movement pattern values for standing still (d=2.05), lateral movements (d=0.76) and sprinting (d=0.77). Large practical significant difference were found between the time spent in the maximal threshold (d=2.07), anaerobic threshold (d=0.92) and sub–threshold (d=7.90) heart rate zones measured during the two halves of match–refereeing. Average work–to–rest ratios of 1:3.5 and 1:5 were found for the first and second halves of rugby match–refereeing, respectively. The information gained regarding the activity profile of SARU referees could be used to determine the influence of rugby refereeing experience on the movement patterns and work–to–rest ratio of rugby referees. It can also provide information for constructing specific training programmes and drills in the development of rugby match–required fitness standards for referees. A key component of a rugby union referee’s game is positioning. Being in the right place at the right time is vital. The results of this study suggest that movements associated with positioning ? namely standing still, walking and lateral movements are the major components of the game of referees’ movement during match–refereeing. However, further research is required on this topic of research. / Thesis (M.A. (Sport Science))--North-West University, Potchefstroom Campus, 2012.

Die term speurverhaal impliseer ’n spesifieke soort verhaal of genre, tradisioneel triviaalliteratuur of ontspanningslektuur, met spesifieke kodes en konvensies. Enige konvensies is egter aanpasbaar en die grense tussen hoë kuns en populêre kultuur is vloeibaar, sodat dit moontlik is dat daar wel ʼn vertakking of subgenre wat die literêre speurverhaal genoem kan word, kon ontwikkel het. Die doel van hierdie verhandeling is om die volgende navorsingsvrae te beantwoord: Is daar wel speurverhale wat as literêre speurverhale gekategoriseer kan word? Indien nie, waarom word die kodes van die speurverhaal as narratiewe strategie gekies vir sekere romans? Wat is die verskille en ooreenkomste tussen die tradisionele speurverhaal en die sogenaamde literêre speurverhaal? Die verskynsel word ondersoek word deur twee romans wat moontlik as literêre speurverhale geklassifiseer kan word, nl. Een vir Azazel (Leroux, 1984) en Die boek van toeval en toeverlaat (Winterbach, 2006), te vergelyk met twee tradisionele speurverhale, nl. Reuk van die dood (Mouton, 2008) en Plaasmoord (Brynard, 2009), aan die hand van sekere struktuurelemente, nl. spanningslyn, plot, intrige, karakterisering, verteller, vertellersperspektief, tyd, en ruimte. ENGLISH : The term detective story indicates a specific kind of story or genre, traditionally recreational and light reading, with specific codes and conventions. However, any set of conventions are pliable and the boundaries between recreational and high art are fluid and constantly shifting. It is therefore possible that a subgenre of the detective story that can be called the literary detective story could have developed. The goal of this dissertation is to answer the following research questions: Are there detective stories that can be categorised as literary detective stories? If not, why is the detective element chosen as a narrative strategy for some novels? What are the differences and similarities between the traditional detective story and the so called literary detective novel? / Dissertation (MA)--University of Pretoria, 2010. / Afrikaans / unrestricted

Thesis (DTh)--University of Stellenbosch, 1995. / ENGLISH ABSTRACT: We live in an age characterised by constant and accelerating change. In the secular world the competition among businesses is so intense that change, adaptation and reorientation have become indispensable to the survival of any large organisation. Organisational management has developed into a science with professional advisors (known as consultants) who are employed on a full-time basis. The Church is an integral part of society and cannot distance itself from the latter. This calls for adaptation and reorientation within the Church as well. However, it has become increasingly evident that within the various denominational Churches no effective mechanisms exist by means of which parishes and synods can be supported in the process of transformation. Church consultants have begun to address this need. Consequently, a new discipline has emerged which employs the methods developed in the secular sciences of management and related, as well as supportive, fields of study. It is important to remember, though, that the Church is a unique kind of organisation with its own nature and identity. Any consultation which does not take this into consideration, is not reliable. For this reason, experts in the field of Practical Theology are studying the entire phenomenon of consultation from a theological point of view. In South Africa, the idea of consultation has also taken root as this kind of service has established itself spontaneously and in an unstructured manner. At present it is being done on an increasingly professional basis, and there are church members who have taken on this task as a full-time ministry. The time has, therefore, come for us to explore, describe and evaluate this issue. This study endeavours to analyse and give a critical account of consultation from a South African - and specifically the Dutch Reformed Church - standpoint. The ultimate aim is to attempt to lay down guidelines which should give theological and structural direction to the development of this kind of ministry within the Dutch Reformed Church. Consequently, this study strives to define the theological principles fundamental to consultation. It has established that the guidance of faith-communities towards change is a basic principle in Scripture. Hence, the Church is seen as an organisation, as well as an organism, and the study emphasises that consultation will have to take into account both these aspects. The development of consultational ministry is reviewed critically by tracing the history and activities of various leading consulting bodies in the U.S.A., Germany and the Netherlands. The course of the process of consultation - a dynamic and interactive process which moves through distinctive stages - has been carefully plotted. Parish involvement seems to be a basic prerequisite in this process. The critical analysis of all the available information is followed by carefully detailed guidelines for parish consultation in South Africa. / AFRIKAANSE OPSOMMING: Die tyd waarin ons lewe word gekenmerk deur versnelde verandering. In die sekulere wereld is die kompetisie tussen ondernemings so sterk dat verandering, aanpassing en herorientering deel van die bestaanswyse en agenda van groot organisasies geword het. Die organisasie wat nie hieraan aandag gee nie, verdwyn. Organisasiebestuur het 'n wetenskap geword met professionele raadgewers wat as konsultante bekend staan as 'n voltydse beroep. Die kerk kan hom nie van die samelewing waarin hy hom bevind, losmaak nie. Ook die kerk moet aanpassings maak en herorienteer in 'n veranderende wereld. Dit het algaande duidelik geword dot daar binne die kerkverband nie effektiewe meganismes bestaan wat gemeentes en groter kerkvergaderings kan help met die proses van aanpassing nie. Kerklike konsultante het algaande in hierdie behoefte begin voorsien.Dit is 'n nuwe dissipline wat met metodieke werk wat in die sekulere wereld in die bestuurswetenskappe en ander ondersteunende dissiplines ontwikkel is. Die kerk is egter 'n unieke tipe organisasie met 'n eie aard en identiteit. Konsultasie wat dit nie in ag neem nie, sal onbetroubaor wees. Daar word dus teologies en krities hieroor besin binne die vakgebied van die Praktiese Teologie. Ook in Suid-Afrika is konsultasie 'n term wat besig is om pos te vat omdat hierdie bediening algaande spontaan en ongestruktureerd sy voete begin vind het. Tans word dit op 'n al meer professionele wyse gedoen en is daar gelowiges wat dit as 'n voltydse bediening begin bedryf. Dit het tyd geword om die aangeleentheid te verken, te beskryf en standpunt daaroor in te neem. Die studie wil uit 'n Suid-Afrikaanse en, spesifiek gereformeerde gesigspunt die saak rondom konsultasie krities beskryf en analiseer. Die uiteindelike doelwit is om riglyne te probeer neerle wat teologies en struktureel rigting kan verskaf aan die ontwikkeling van die bediening binne die Nederduitse Gereformeerde Kerk. Die studie poog gevolglik om 'n greep te kry op die teologiese beginsels waaroor dit in konsultasie gaan. Dit bevind dat die begeleiding van geloofsgemeenskappe tot verandering 'n wesentlike beginsel in die Skrif is. Voorts beskryf dit die kerk vanuit die hoek van organisasie en organisme en beklemtoon dit die feit dat konsultasie met albei hierdie perspektiewe sal moet rekening hou. Die ontwikkeling van die konsultasiebediening word krities bespreek deur die geskiedenis en funksionering van verskeie van die toonaangewende konsultasie-instansies in die VSA, Duitsland en Nederland na te gaan. Die verloop van die konsultasieproses as dinamiese en interaktiewe gebeure wat deur verskillende fases beweeg, word uiteengesit. Gemeentebetrokkenheid in die konsultasieproses blyk 'n basiese uitgangspunt te wees. Na 'n kritiese analise van al die gegewens word riglyne vir 'n Suid-Afrikaanse gemeentelike konsultasiebediening uiteengesit.

INTRODUCTION AND AIM - Cardiovascular disease is globally a major risk factor for morbidity and mortality. It is caused by various factors, one of which is an abnormal haemostatic process. Fibrinogen is a haemostatic factor that is considered to be an independent risk factor for cardiovascular disease. Elevated fibrinogen can be caused by environmental and genetic factors which increase the risk of the occurrence of thrombosis. The fibrinogen y' chain, which is one of the three chains of fibrinogen, has two different variants, the yA and y’. The presence of the fibrinogen y’ chain has been associated with thrombotic disorders. Many studies have investigated the fibrinogen variables in Caucasian individuals, but only a few such studies have been conducted on non-Caucasian individuals. The genetic diversity of ethnic groups differs and could cause differences in the fibrinogen variables between these groups. Fibrinogen is known to increase with age; therefore to explain changes over time in fibrinogen concentrations it was also important to investigate whether genetic determinants and possible gene–environment interactions influenced fibrinogen over time. In this study the main aim was to determine the change in the fibrinogen variables over a five-year period within a black South African cohort subdivided according to genotypes associated with fibrinogen variables, and to determine whether the observed changes were modulated by environmental factors. PARTICIPANTS AND METHODS - Data [baseline (n=2010) and follow-up (n=1288)] were collected in the Prospective Urban and Rural Epidemiology (PURE) study during 2005 and 2010 from apparently healthy black men and women aged between 35 and 65 years and residing in rural or urban settlements. Experimental methods included analysis of fibrinogen and fibrinogen y’ concentrations, single nucleotide polymorphisms (SNPs) and determination of environmental factors associated with the fibrinogen variables. RESULTS - The fibrinogen variables increased significantly from 2005 to 2010 in both the rural and urban participants, as well as in both men and women. The major environmental factors that affected the fibrinogen variables were C-reactive protein (CRP), interleukin-6 (IL-6), body mass index (BMI), glycated haemoglobin (HbA1c), age, blood lipids, human immunodeficiency virus (HIV) and tobacco use. Fibrinogen increased consistently from 2005 to 2010 in the respective genotypes of all SNPs analysed, except in the FGG 9340 T>C homozygous mutant carriers. Fibrinogen y’ also increased in general in most genotypes from 2005 to 2010, except in the FGG 10034 C>T mutant allele carriers, where a decrease was observed. It was determined that CRP was the only environmental factor that influenced the change in fibrinogen over time and that FGG 10034 C>T was the only SNP that influenced the change in fibrinogen y’ over the five years. Four gene–environment interactions also influenced fibrinogen on a cross-sectional level, i.e. FGA 2224 G>A with age, FGB Arg448Lys with HIV status, FGB 1643 C>T with urbanisation and FGB 1038 G>A with HbA1c. Only the FGG 9340 T>C with HbA1c interaction was found to predict change in fibrinogen concentrations over the five years. CONCLUSION - Both environmental and genetic factors significantly influenced the fibrinogen variables cross-sectionally as well as prospectively. It was clear that the influence of the environmental factors was mediated by genetic polymorphisms and vice versa, as can be seen by the gene–environment interactions found in this study. An important finding of this study was that the interaction of HbA1c with two SNPs on fibrinogen variables may explain the known inconsistent relationship found between fibrinogen concentrations and diabetes. / MSc (Dietetics), North-West University, Potchefstroom Campus, 2014

INTRODUCTION AND AIM - Cardiovascular disease is globally a major risk factor for morbidity and mortality. It is caused by various factors, one of which is an abnormal haemostatic process. Fibrinogen is a haemostatic factor that is considered to be an independent risk factor for cardiovascular disease. Elevated fibrinogen can be caused by environmental and genetic factors which increase the risk of the occurrence of thrombosis. The fibrinogen y' chain, which is one of the three chains of fibrinogen, has two different variants, the yA and y’. The presence of the fibrinogen y’ chain has been associated with thrombotic disorders. Many studies have investigated the fibrinogen variables in Caucasian individuals, but only a few such studies have been conducted on non-Caucasian individuals. The genetic diversity of ethnic groups differs and could cause differences in the fibrinogen variables between these groups. Fibrinogen is known to increase with age; therefore to explain changes over time in fibrinogen concentrations it was also important to investigate whether genetic determinants and possible gene–environment interactions influenced fibrinogen over time. In this study the main aim was to determine the change in the fibrinogen variables over a five-year period within a black South African cohort subdivided according to genotypes associated with fibrinogen variables, and to determine whether the observed changes were modulated by environmental factors. PARTICIPANTS AND METHODS - Data [baseline (n=2010) and follow-up (n=1288)] were collected in the Prospective Urban and Rural Epidemiology (PURE) study during 2005 and 2010 from apparently healthy black men and women aged between 35 and 65 years and residing in rural or urban settlements. Experimental methods included analysis of fibrinogen and fibrinogen y’ concentrations, single nucleotide polymorphisms (SNPs) and determination of environmental factors associated with the fibrinogen variables. RESULTS - The fibrinogen variables increased significantly from 2005 to 2010 in both the rural and urban participants, as well as in both men and women. The major environmental factors that affected the fibrinogen variables were C-reactive protein (CRP), interleukin-6 (IL-6), body mass index (BMI), glycated haemoglobin (HbA1c), age, blood lipids, human immunodeficiency virus (HIV) and tobacco use. Fibrinogen increased consistently from 2005 to 2010 in the respective genotypes of all SNPs analysed, except in the FGG 9340 T>C homozygous mutant carriers. Fibrinogen y’ also increased in general in most genotypes from 2005 to 2010, except in the FGG 10034 C>T mutant allele carriers, where a decrease was observed. It was determined that CRP was the only environmental factor that influenced the change in fibrinogen over time and that FGG 10034 C>T was the only SNP that influenced the change in fibrinogen y’ over the five years. Four gene–environment interactions also influenced fibrinogen on a cross-sectional level, i.e. FGA 2224 G>A with age, FGB Arg448Lys with HIV status, FGB 1643 C>T with urbanisation and FGB 1038 G>A with HbA1c. Only the FGG 9340 T>C with HbA1c interaction was found to predict change in fibrinogen concentrations over the five years. CONCLUSION - Both environmental and genetic factors significantly influenced the fibrinogen variables cross-sectionally as well as prospectively. It was clear that the influence of the environmental factors was mediated by genetic polymorphisms and vice versa, as can be seen by the gene–environment interactions found in this study. An important finding of this study was that the interaction of HbA1c with two SNPs on fibrinogen variables may explain the known inconsistent relationship found between fibrinogen concentrations and diabetes. / MSc (Dietetics), North-West University, Potchefstroom Campus, 2014

The aim of the dissertation was to design a realistic, low-complexity non-binary (NB) low density parity check (LDPC) coded space-time-frequency (STF) coded multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system with an iterative joint decoder and detector structure at the receiver. The goal of the first part of the dissertation was to compare the performance of different design procedures for NB-LDPC codes on an additive white Gaussian noise (AWGN) channel, taking into account the constraint on the code length. The effect of quantisation on the performance of the code was also analysed. Different methods for choosing the NB elements in the parity check matrix were compared. For the STF coding, a class of universal STF codes was used. These codes use linear pre-coding and a layering approach based on Diophantine numbers to achieve full diversity and a transmission rate (in symbols per channel use per frequency) equal to the number of transmitter antennas. The study of the system considers a comparative performance analysis of di erent ST, SF and STF codes. The simulations of the system were performed on a triply selective block fading channel. Thus, there was selectivity in the fading over time, space and frequency. The effect of quantisation at the receiver on the achievable diversity of linearly pre-coded systems (such as the STF codes used) was mathematically derived and verified with simulations. A sphere decoder (SD) was used as a MIMO detector. The standard method used to create a soft-input soft output (SISO) SD uses a hard-to-soft process and the max-log-map approximation. A new approach was developed which combines a Hopfield network with the SD. This SD-Hopfield detector was connected with the fast Fourier transform belief propagation (FFT-BP) algorithm in an iterative structure. This iterative system was able to achieve the same bit error rate (BER) performance as the original SISO-SD at a reduced complexity. The use of the iterative Hopfield-SD and FFT-BP decoder system also allows performance to be traded off for complexity by varying the number of decoding iterations. The complete system employs a NB-LDPC code concatenated with an STF code at the transmitter with a SISO-SD and FFT-BP decoder connected in an iterative structure at the receiver. The system was analysed in varying channel conditions taking into account the effect of correlation and quantisation. The performance of different SF and STF codes were compared and analysed in the system. An analysis comparing different numbers of FFT-BP and outer iterations was also done. AFRIKAANS : Die doel van die verhandeling was om ’n realistiese, lae-kompleksiteit nie-binˆere (NB) LDPC gekodeerde ruimte-tyd-frekwensie-gekodeerde MIMO-OFDM-sisteem met iteratiewe gesamentlike dekodeerder- en detektorstrukture by die ontvanger te ontwerp. Die eerstem deel van die verhandeling was om die werkverrigting van verskillende ontwerpprosedures vir NB-LDPC kodes op ’n gesommeerde wit Gausruiskanaal te vergelyk met inagneming van die beperking op die lengte van die kode. Verskillende metodes om die nie-bineêre elemente in die pariteitstoetsmatriks te kies, is gebruik. Vir die ruimte-tyd-frekwensiekodering is ’n klas universele ruimte-tyd-frekwensiekodes gebruik. Hierdie kodes gebruik lineêre pre-kodering en ’n laagbenadering gebaseer op Diofantiese syfers om volle diversiteit te bereik en ’n oordragtempo (in simbole per kanaalgebruik per frekwensie) gelyk aan die aantal senderantennes. Die studie van die sisteem oorweeg ’n vergelykende werkverrigtinganalisie van verskillende ruimte-tyd-, ruimte-freksensie- en ruimte-tyd-frekwensiekodes. Die simulasies van die sisteem is gedoen op ’n drievoudig selektiewe blokwegsterwingskanaal. Daar was dus selektiwiteit in die wegsterwing oor tyd, ruimte en frekwensie. Die effek van kwantisering by die ontvanger op die bereikbare diversiteit van lineêr pre-gekodeerde sisteme (soos die ruimte-tyd-frekwensiekodes wat gebruik is) is matematies afgelei en bevestig deur simulasies. ’n Sfeerdekodeerder (SD) is gebruik as ’n MIMO-detektor. Die standaardmetode wat gebuik is om ’n sagte-inset-sagte-uitset (SISO) SD te skep, gebruik ’n harde-na-sagte proses en die maksimum logaritmiese afbeelding-benadering. ’n Nuwe benadering wat ’n Hopfield-netwerk met die SD kombineer, is ontwikkel. Hierdie SD-Hopfield-detektor is verbind met die FFT-BP-algoritme in iteratiewe strukture. Hierdie iteratiewe sisteem was in staat om dieselfde bisfouttempo te bereik as die oorspronklike SISO-SD, met laer kompleksiteit. Die gebruik van die iteratiewe Hopfield-SD en FFT-BP-dekodeerdersisteem maak ook daarvoor voorsiening dat werkverrigting opgeweeg kan word teen kompleksiteit deur die aantal dekodering-iterasies te varieer. Die volledige sisteem maak gebruik van ’n QC-NB-LDPC-kode wat met ’n ruimte-tyd-frekwensiekode by die sender aaneengeskakel is met ’n SISO-SD en FFT-BP-dekodeerder wat in ’n iteratiewe struktuur by die ontvanger gekoppel is. Die sisteem is onder ’n verskeidenheid kanaalkondisies ge-analiseer met inagneming van die effek van korrelasie en kwantisering. Die werkverrigting van verskillende ruimte-frekwensie- en ruimte-tyd-frekwensiekodes is vergelyk en in die sisteem ge-analiseer. ’n Analise om ’n wisselende aantal FFT-BP en buite-iterasies te vergelyk, is ook gedoen. Copyright / Dissertation (MEng)--University of Pretoria, 2010. / Electrical, Electronic and Computer Engineering / unrestricted