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Design of Efficient Adaptive Beamforming Algorithms for Novel Mimo Architectures

Thesis Info

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Author

Engr. Jawwad Ahmad

Program

PhD

Institute

Iqra University

City

Karachi

Province

Sindh

Country

Pakistan

Thesis Completing Year

2014

Thesis Completion Status

Completed

Subject

Applied Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/2725/1/2716S.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676725825647

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The major issue in the mobile communication is the presence of several types of im- pairments in the wireless medium. There are many types of impairments, the important one is refer to as fading which is defined as the interference occurred in the received signal because of its multiple copies arrived through multi paths. It creates considerable changes in receive signal power and therefore counted as significantly destructive in nature. Fading introduces significant distortion and disturbances in almost all wireless radio signal. The major cause of the fading is multipath propagation of the signals and the relative movement of mobile transmitting and/or receiving device. The cancellation of fading effect is essential to achieve higher data rate and better ser- vice quality with similar radiating power and/or bandwidth. Diversity is one of the im- portant techniques to reduce the effect of fading. In order to achieve different diversity types multiple input multiple output antenna array is employed. If a switchable or movable beam pattern is connected to multiple input multiple output (MIMO) antenna system; the system is referred to as smart system. In order to perform xivthis function, smart antenna requires certain signal processing and adaptive computa- tion. Such adaptive computations are performed through some algorithms known as adaptive beamforming algorithms. This dissertation develops three novel MIMO beamforming architecture using decision directed mode in order to exploit spatial and temporal diversities. Moreover, we pro- posed three new adaptive beamforming algorithms for fast convergence and high beam gain. The simulation results prove their effectiveness over other available algorithms and architectures.
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عورت اور مصری تہذیب

عورت اور مصری تہذیب

قدیم مصری تہذیب میں اکثر و بیشتر بادشاہ اپنی بہن سے شادی کرتا حتیٰ کہ بیٹی سے بھی شادی رچائی جاتی تھی ۔اس کے لیے تاویل یہ پیش کی جاتی کہ شاہی خون خالص رہے۔ فرعونی دور کی تحریروں کو جب ڈی کوڈ کیا گیا تو معلوم ہو ا کہ مصری شاعری میں لفظ بھائی بہن محبوب اور محبوبہ کے معنوںمیں بھی استعمال ہوتا تھا ۔بادشاہوں کے حرموں میں بہنوں کے علاوہ سینکڑوں کنیزیں رکھنے کا شوق اپنی جگہ مگر متوسط آمدنی والے مصر کے عام لوگ یک زوجگی پر قانع رہتے تھے ۔خانگی زندگی بدیہی طور پر بڑی حد تک بہتر تھی۔عورت کو طلاق دینا آسان نہ تھا ۔عقد میں آنے والی عورت کو جائیداد میں اچھا خاصا حصہ ملتا۔ایک مغربی مفکر کا قول ہے کہ کسی بھی قدیم یا جدید تہذیب نے عورت کو وہ بلند قانونی رتبہ نہیں دیا جتنا وادی ِ نیل کے باشندوں نے دیا۔ اپنی تند خو (سقراطی) بیویوں کو گھر میں بند رکھنے کے عادی یونانی سیاح یہ آزادی دیکھ کر ششدر رہ جاتے ۔ فرعونی دور کے ادب میں عورت کی حیثیت اور عظمت کے گُن گائے جاتے تھے۔ مصری عورت سے محبت ایک قومی فریضہ سمجھا جاتا تھا۔ مصری مرد کو صرف مصری عورت سے ہی قلبی اور جنسی وابستگی کی ترغیب دی جاتی۔ ایک مصری بزرگ اپنے سننے والوں کو سمجھاتے ہیں کہ’’ باہر سے آنے والی ایسی عورتوں سے ہوشیار رہو ۔یہ گہرے پانیوں کے بھنور کی مانند ہوتی ہیں‘‘۔اسی طرح ایک مصری اپنے بیٹے کو نصیحت کرتے ہوئے لکھتا ہے کہ’’اگر تم نے اپنا گھر کامیابی کے ساتھ سجا سنوار لیا ہے اور خوب صورت ترین بیوی تمھاری آغوش میں ہے تو اس کا پیٹ بھرو اور کمر پر کپڑا ڈالو۔اس کی خوشی کا سامان مہیا کرو کیوں...

Comparative Effect Of Tetrapack Juices And Fresh Fruit Juices On Blood Glucose Level Among Healthy Individuals Comparative Effect of Juices on Blood Glucose Level

Uses of tetra pack juices enhances the risk of diabetes and obesity. People were unaware of impact of fresh fruit juices on health. Objective: To compare the effect of tetra pack juices and fresh fruit juices on blood glucoselevels among healthy individuals Methods: 10 participants were selected using an internationalstandard Glycemic Index (GI) test protocol. After getting their fasting blood sample theywereinstructed to consume all the juice served in a period of 5 min. Further blood samples were takenat different intervals of time that is 0, 30, 60, 90, 120 and 150 minutes after consumption. Participants wereremained sedentaryduring each session. Blood was obtained by finger-prick and tested by the glucometer. Results: The glycemic index of Apple juice Nestle has the glycemic index of 95.87, Orangejuice Nestle has the GI value 93.78, Apple juice fresh has the GI value of 92.17 and Orangejuice fresh has the glycemic index value of 99.07, respectively Conclusions: Detailed study of glycemic index of tetrapack juices (Nestle Apple and Orangejuice) and fresh fruit juices (Apple and Orange juice) showed similar impact on the blood glucose level of healthy individual. In the study, both types of juices were found to be equally hyperglycemic (GI 70+) causing a fast rise in blood-sugarlevels, hence should not be given to diabetic patients

Synthesis, Band Gap Tuning, Characterization and Photosensitization of Tio 2 Nanoparticles for Application in Hybrid Solar Cells

In this work an endeavor was made to fabricate hybrid bulk heterojunctions solar cells based on doped and un-doped TiO 2 nanoparticles blended with the well-known organic polymer Poly(3-hexyl thiophene) and co-grafted with porphyrin and carminic acid. Charge transfer complex formation between the donor and acceptor dyes helped in increasing the photo induced generated current. To achieve this end sol-gel method was employed to synthesize anatase titania, which was characterized by electronic absorption spectroscopy, X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The first part of the research deals with the band gap modulation of TiO 2 by doping it with selected transition metals (2-8% Cu, Ni and Cr). This was aimed to study the effect of tuning the band gap of TiO 2 on the efficiency of the fabricated solar cells by extending the absorption spectrum of titania to the visible region. The doped materials were also characterized using optical and morphological techniques to investigate their properties. Direct band gap of TiO 2 (3.9 eV) was found to be significantly reduced to 2.94, 3.40 and 3.60 eV for 2% Cu, 4% Ni and 2% Cr-doped materials respectively. Higher dopant concentrations induced the widening of the band gap according to the Burstein-Moss phenomenon. XPS results confirmed the substitution of Ti 4+ ions by the doped transition metal ions. Bulk heterojunctions solar cells were fabricated using un- doped and doped titania in combination with P3HT in order to investigate the effect of doping on the performance of the device. An enhancement of the photo-generated current was observed by using doped titania. This increase could be ascribed to the tuning of the band gap of titania to absorb effectively in the visible region. Maximum photocurrent was obtained by employing Cu-doped TiO 2 . However the value of FF was reduced owing to the low V oc values. The second portion of this research is dedicated to investigate the effect of photosensitization of TiO 2 and M-TiO 2 (M= Cu, Ni, Cr) on the efficiency of solar cells. A metallated phthalocyanine (Ni-Pc) was used to functionalize TiO 2 nano- particles in an attempt to extend the absorption spectrum of titania to visible region. The grafted materials were optically analyzed using electronic absorption, fluorescence IVemission and FT-IR spectroscopy to study the successful chemisorption of the dye on TiO 2 surface. These dye sensitized TiO 2 and M-TiO 2 were employed to fabricate solid state solar cells using P3HT. I-V measurements were performed to see the effect of dye concentration on the performance of solar cells. The plots showed that maximum I sc was achieved using 15 μM of Ni-Pc and the efficiency of the device was enhanced 3 times as compared to pristine titania blended with P3HT. The doped grafted titania using 15 μM of Ni-Pc showed higher I sc compared to un-doped grafted materials but the FF was reduced. This lowered the overall efficiency. The effect of co-grafting was also investigated by preparing photo-active nano-hybrid material consisting of titania nanoparticles, carminic acid and sulphonic acid functionalized porphyrin. Adsorption of free base porphyrin on TiO 2 resulted in its metallation which was evidenced by the disappearance of two out of four Q-bands in the UV-visible spectra of porphyrin. The adsorption of carminic acid resulted in the formation of charge transfer complex with titania nanoparticles. This was confirmed by the electronic absorption and fluorescence emission spectroscopies. Energy level diagram showed that the interaction among the constituents of the nano hybrid assembly permitted the flow of electron in a cascade manner from carminic acid to TiO 2 .This also allowed direct flow of electrons either from carminic acid or porphyrin towards titania. The material was used as an active blend in hybrid bulk hetero-junction solar cells. Co- functionalized (co-grafted) TiO 2 based devices were found three times more efficient than the reference device but morphology of the device proved a major setback.