How to Interface Gps with 8051 Microcontroller Essay Example

How to Interface Gps with 8051 Microcontroller Essay How to interface GPS with 8051 Microcontroller (AT89C51) Project Code: MC082 * Summary * Description * Circuit Diagram * Video * Code * Components Summary GPS has become an efficient tool in the field of scientific use, commerce, surveillance and tracking. This project presents a small application based on Global Positioning System. It depicts the use of GPS module/receiver to find latitude and longitude of its location. The data obtained from GPS receiver (GPGGA sentence) is processed by the microcontroller to extract its latitude and longitude values. The GPS Module has been interfaced with AT89C51 and the location values are displayed on a 162 LCD interface. Description How to interface GPS with 8051 Microcontroller (AT89C51) Project Code: MC082 * Summary * Description * Circuit Diagram * Video * Code * Components Summary GPS has become an efficient tool in the field of scientific use, commerce, surveillance and tracking. This project presents a small application based on Global Positioning System. It depicts the use of GPS module/receiver to find latitude and longitude of its location. The data obtained from GPS receiver (GPGGA sentence) is processed by the microcontroller to extract its latitude and longitude values. The GPS Module has been interfaced with AT89C51 and the location values are displayed on a 162 LCD interface. Description The GPS module continuously transmits serial data (RS232 protocol) in the form of sentences according to NMEA standards. The latitude and longitude values of the location are contained in the GPGGA sentence (refer NMEA format). In this program, these values are extracted from the GPGGA sentence and are displayed on LCD. We will write a custom essay sample on How to Interface Gps with 8051 Microcontroller specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on How to Interface Gps with 8051 Microcontroller specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on How to Interface Gps with 8051 Microcontroller specifically for you FOR ONLY $16.38 $13.9/page Hire Writer The serial data is taken from the GPS module through MAX232 into the SBUF register of 8051 controller (refer serial interfacing with 8051). The serial data from the GPS receiver is taken by using the Serial Interrupt of the controller. This data consists of a sequence of NMEA sentences from which GPGGA sentence is identified and processed. The extraction of location values is done as follows. The first six bytes of the data received are compared with the pre-stored ($GPGGA) string and if matched then only data is further accounted for; otherwise the process is repeated again. From the comma delimited GPGGA sentence, latitude and longitude positions are extracted by finding the respective comma positions and extracting the data. The latitude and longitude positions extracted are displayed on the LCD interfaced with AT89C51. To obtain more details (other than latitude and longitude) from the GPS receiver, GPRMS sentence can be used. Refer next article. The circuit connections are as follows: Receiver1 (R1) of MAX232 has been used for the serial communication. The receiver pin of GPS module is connected to R1IN (pin13) of MAX232. R1OUT pin 12) of MAX232 is connected to RxD (P3. 0) of AT89C51. Pins 1-3 of port P1 (P1. 0, P1. 1 amp; P1. 2 respectively) of AT89C51 are connected to the control pins (RS, R/Wamp; EN) of LCD. The data pins of LCD are connected to Port P2 of the controller. The latitude and longitude positions are displayed on the LCD. Ckt dgrm CODE /* Basic program to show latitude and longitude on LCD extracted from GPGGA statement */ #includelt;r eg51. hgt; #define port2 P2 sbit rs = P1^0; sbit rw = P1^1; sbit e = P1^2; char info[70]; char test[6]={$GPGGA}; char comma_position[15]; unsigned int check=0,i; nsigned char a; void receive_data(); void lcd_latitude(); void lcd_longitude(); //DELAY FUNCTION void delay(unsigned int msec) { int i,j ; for(i=0;ilt;msec;i++) for(j=0;jlt;1275;j++); } // LCD COMMAND SENDING FUNCTION void lcd_cmd(unsigned char item) { port2 = item; rs= 0; rw=0; e=1; delay(1); e=0; return; } // LCD DATA SENDING FUNCTION void lcd_data(unsigned char item) { port2 = item; rs= 1; rw=0; e=1; delay(1); e=0; return; } // LCD STRING SENDING FUNCTION void lcd_string(unsigned char *str) { int i=0; while(str[i]! =

How to Create a Persuasive Speech on Non-College Education

How to Create a Persuasive Speech on Non-College Education A persuasive speech on non-college education is one which is intended to convince your audience to do something at the end. Whether you want someone to stop littering, to change the way they think about an important issue, or to take action, persuasive speeches are the most effective way to convince your audience into taking your side. But there are many elements necessary to prepare a successful persuasive essay. You Need to Know Your Topic!  You need to learn a great deal about your topic. Whatever the topic might be it is important that you learn as much as you can before you start writing your persuasive speech on non-college education. If you are not already well-versed in the subject it is important that you do research and learn as much as you can. If your argument is one which is controversial it is best to know all sides of the issue. Regardless of what side of the argument you might support, you will be much more persuasive if you are able to address the opposing side period Spend time reading articles or books about the topic. You can visit your library and ask a librarian to lend a hand in finding the best books. Make sure that any sources you use are reliable such as academic articles or books published by reputable authors. Opinion oriented sources like a news editorial might be valuable with regard to finding out what other people think about the issue, but are not necessarily something you want to quote as a reference. Fun tip: If you are allowed to choose your topic for the persuasive speech on non-college education, dont select an obvious statement which cannot be debated. Saying that littering is bad for the environment, as an example, its far too general. Theres no one who would disagree with that. When you think about your topic select something which is debatable and has definite sources. You Need to Know Your Goal!  It is important for you to understand what you are trying to achieve when writing your speech. Do you want somebody to take action at the end of your speech such that they begin doing something you spoke of during the speech? Or do you want people to vote in favor of something pertaining to your speech? You want to craft a speech such that the goal is spelled out early for your audience so they understand what your message really is. You Need to Know Your Audience!  When you write your persuasive speech on non-college education it is important that you understand your audience. An audience who knows very little about your topic will obviously need additional background information and very simple language. An audience full of experts on the topic will find such a speech particularly mundane. Likewise, if you are speaking to an audience already supportive of your view it will be much easier to persuade them to take action and you wont have to convince them that you are correct but that they need to do something. By contrast if your audience does not agree with your sentiments, you will have to focus the majority of your efforts on persuading them to consider your point of view. We hope this guide will make the effort of doing your assignment at least a little bit easier. Don’t forget our 11 facts and 20 controversial persuasive speech topics for college students that traditionally come in package.

The Case of Revision R v G and Another Essay Example | Topics and Well Written Essays - 3000 words

The Case of Revision R v G and Another - Essay Example However, the House of Lords overruled, on the grounds that an element of men's rea was a requirement in all cases involving serious offenses. The boys were therefore not found guilty of arson, or the crime of causing damage by fire3. The former was classified as objective recklessness and the latter as subjective recklessness and this had to be assessed by reference to the reasonable man. The case of Cunningham4 established conclusively that subjective recklessness involving offenses committed â€Å"intentionally and recklessly† will make the accused liable. But Caldwell imputed liability for objective recklessness as well, although Lord Edmund Davies noted a dissenting opinion on the objective recklessness of the defendant as follows: â€Å"†¦a jury could not on those words alone, properly convict him of recklessness simply because they considered that the risk ought to have crossed his mind†¦Ã¢â‚¬ 5 The House of Lords decision however overruled on the grounds that foresight or the ability to make an assessment of the consequences was deemed to be an essential part of recklessness as laid out under Section 1 of the Criminal Damage Act. The basis upon which the lower Court’s decision was overruled was that when a judgment was made on the liability for objective recklessness without making any allowance for the youth of the defendants or for whether they had the mental capacity to understand the consequences of their actions, it is bound to be erroneous. The House of Lords held that since the boys did not maliciously and deliberately set out to cause damage to the property, neither did they foresee the risk of the damages that could occur through the spread of the fire, they could not be deemed to be guilty of arson. A conviction for a crime should prove not merely an act of omission leading to a crime but also a culpable state of mind, in accordance with the principle of m en's rea. Therefore a defendant who genuinely did not perceive the risk cannot be exposed to serious punishment.

Learning, Coaching, Development Essay Example | Topics and Well Written Essays - 2500 words

Learning, Coaching, Development - Essay Example Thus the training program would be differently focused as now teaching, helping, guiding, and developing the employees would be given attention such that the multi channel strategy can successfully be implemented. Employee development is an essential aspect of any business organization that is carried out by the Human Resources Team of the organization. Development and hence training is essential as it helps the employees to improve upon their skills and effectiveness (Werner and DeSimone 2011). Individual learning and development have always proved to be beneficial for organizational employees who become more committed, responsible, and motivated to their tasks followed by such training program. Organizations thus find it an essential part of the HRM processes to include training processes, particularly focused on learning and coaching, for development of employees (Park 2007). Based on the case study and the need for the organization to develop its employees towards the use and imp lementation of multiple channel communication for their business, a four weeks training program will be developed, along with discussion of the different stages of the training cycle, and the impact of learning and coaching on development of employees. 2. Identification of Training and Development Needs: When training and development is considered within an organization, there are individual roles and responsibilities of the organizational managers, the professionals of the HR team, and the employees (Jackson, Schuler and Werner 2011). The basic roles and responsibilities can be outlined as follows: Managers need to understand the developmental needs of the employees and cooperate with the HR team to implement the necessary training measures. They need to encourage the participation of the employees in the program and offer the learning and coaching techniques to them thereby participating and giving effort in the program (Jackson, Schuler and Werner 2011). The HR professionals need to coordinate with the managers and determine the employee needs for development. Accordingly, the training program needs to be planned and implemented followed by evaluation. To communicate with the employees, and administer the program involving complete participation of the employees, are the responsibilities of the HR team (Jackson, Schuler and Werner 2011). The role of the employees is to understand the organizational objectives, and hence realize the need for their development of skills and effectiveness. Based on their understanding they need to cooperate with both the managers and the HR team to successfully implement the training program. The learning and coaching offered to them by their managers and HR team need to be considered as opportunities for them to enhance their positive skills (Jackson, Schuler and Werner 2011). 2.1. Basic Skills and Competencies for Call Canter Work: Call centers have emerged to be significant development for organization of white-collar works . Several businesses are now outsourcing their works and call center proves to be a major development

Prepare a persuasive speech on the importance of alcoholism Essay

Prepare a persuasive speech on the importance of alcoholism prevention. your audience is a group of 20 high school students and their parents - Essay Example Chemical properties of alcohol are such that it affects your Central Nervous System (CNS) which includes the â€Å"brain.† Alcohol in your blood decreases the brain activity and depresses the expression of certain anxieties. As a result, you feel better about yourself and less worried. Therefore, you feel more socially skilled. Even the physicians prescribe CNS depressants such as alcohol to treat anxiety, muscle tension, pain, insomnia and panic attacks. There are many other drugs that have similar effects to alcohol, example: narcotics, barbiturates, benzodiazepines and chloral hydrate. We need to understand why people crave for alcohol. It is not merely a person’s fault. Alcohol has the â€Å"addicting effect† on human beings due to its chemical properties. And also, individuals under the influence are usually violent. You may feel tough after you have had a beer. But the sad truth is â€Å"alcohol is controlling you†, not the other way around. Intoxicated individuals may neglect and abuse children, harm women and disabled or put their lives at risk. In many cases people have confessed that they were under the influence when behaving violently. Alcohol related violence is a severe social problem in the world. Over 100,000 students of age 18 to 24 are victims of alcohol-related sexual assault or rape. Another 400,000 students had unprotected sex while too intoxicated to know if they consented to having sex. If you are not concerned about the society at large you should be concerned about your own well being. Alcohol impairs your judgment, creates beer bellies and leads to hangovers. One day you might wake up from hangover to find out that you are a teenage mother, single parent, need an abortion, having AIDS or sexually transmitted infections (STIs). Alcohol consumption weakens the immune system. In other words alcoholics are more likely to die from AIDS, tuberculosis and sexually transmitted infections (STIs) compared to the

Implementation of Wireless Receiver Algorithms

Implementation of Wireless Receiver Algorithms Figure 1 System Specifications (Tsimenidis, 2016) Figure 2 Message format (Tsimenidis, 2016) Figure 3 Non-coherent receiver (Tsimenidis, 2016) Figure 4 Coherent receiver (Tsimenidis, 2016) Figure 5 Receiver Front-End (Tsimenidis, 2016) Figure 6 Frequency response of a passband filter (Tsimenidis, 2016) Figure 7 Band-pass filter response Figure 8 Band-pass filter input/output Figure 9 Implemented DPSK demodulator (Tsimenidis, 2016) Figure 10 Low-pass filter input/output Figure 11 Optima sample time diagram Figure 12 Symbol with 40 samples (Tsimenidis, 2016) Figure 13 Early-Late sample at an arbitrary point (Tsimenidis, 2016) Figure 14 Early-Late sample at the maximum point of power (Tsimenidis, 2016) Figure 15 Early-Late symbol synchronization input/output Figure 16 Result of non-coherent receiver detection Figure 17 IQ Downconverter (Tsimenidis, 2016) Figure 18 Sine and cosine table graphs Figure 19 Index control flow (Tsimenidis, 2016) Figure 20 Filter comparison (Tsimenidis, 2016) Figure 21 Down-conversion: x3I vs. x3Q counter clockwise Figure 22 Down-conversion: x4I vs. x4Q counter clockwise Figure 23 x6I vs. x6Q Figure 24 Averaging approach to overcome the jitter (Tsimenidis, 2016) Figure 25 Code to solve the jitter Figure 26 Principle of the differential detector (Tsimenidis, 2016) Figure 27 Constellation without Phase Offset (dI Vs dQ) Figure 28 Result of coherent receiver detection using differential coherent demodulator Figure 29 BPSK and DPSK BER comparison (Tsimenidis, 2016) Figure 30 Costas Loop algorithm (Tsimenidis, 2016) Figure 31 Costas loop: yQ vs. yI Figure 32 Message obtained using Costas loop Figure 33 BER comparison of different modulation schemes and techniques (Sklar, 1983) This project is focused on implementing and coupling several functional blocks that will allow us to detect, extract and decode a wireless message that is being broadcasted in the Merz lab of computers. In the following sections, we will find the implementations of coherent and non-coherent receivers. In the section 1 we define the basic background knowledge that will be commonly used in the posterior phases of the report. We define the basic structure and features of the transmitter as well as the message format that the system is intended to detect. Finally, we define what is a coherent and a non-coherent system and provide a classification about the different techniques. In the section 2 we will analyse the non-coherent receiver implementation from the message acquisition, going to the filter section, signal scaling and refinement, using a DPSK demodulator to define the probable symbols represented, then establishing a synchronization for the symbol and finally presenting the message obtained. The section 3 will focus in the realization of a coherent receiver, considering two possible variations on this type of implementation: the first will be developed using a differential coherent demodulator, in this technique we will not recover the carrier signal. The second implementation of this receiver, will be done using a carrier recovery technique, which is in this case a Costas Loop Algorithm. Some common blocks are done in all the possible implementations that were carried out during this project: the first is the receiver front-end which is the responsible to acquire and prepare the signal for the posterior processing. To recover the symbol synchronization, we use a technique called early-late gate, this will let us know what is the most convenient instant of the time to sample the signal. For the case of coherent signal, we must adapt this technique to apply it separately for the signal I (in-phase) and Q (quadrature). The section 4 contains analysis, conclusions and discussions of the results obtained during the realization of the phases. The last sections of the report detail the references used for further explanations and the different programs used for implementing each block. In each section, we include little further explanations that could be referred to understand the steps and details that have been done in the corresponding section. 1. Background knowledge 1.1. Aims and objectives The focus of this project is to demonstrate the implementation and the behaviour of data links using Radio Frequency as media and different techniques. Basically, we use two techniques: coherent and non-coherent implementations. A further explanation of these techniques will be done in the following sections. A second implementation of a coherent receiver will be carried out by using a phase recovery technique with the Costas Loop and coupling the posterior phase to this block. The specifications of the system to be implemented could be defined as a set of blocks connected as follows: Figure 1 System Specifications (Tsimenidis, 2016) Where the transmitter has been already implemented, therefore the work will be carried out in the receiver algorithm to obtain the final data, which of course must be in a human readable format. We also must consider that the format of the message that is being broadcasted wirelessly in the Merz lab has the following format: Figure 2 Message format (Tsimenidis, 2016) 1.2. Digital modulation The digital modulation process refers to a technique in which the digital representation of the information is embedded in a signal, a carrier typically a sinusoidal signal, in such a way that this information will modify an established parameter of the signal. We can define a sinusoidal carrier in a general way as a signal that will correspond to the equation: Where the information could be embedded in this will be called amplitude modulation, if the parameter this will be called frequency modulation and finally the phase modulation will be obtained if we embed the data in the expression. Regard to the symbol this is called the angular frequency, it is measured in radians per second, this is related to the frequency (f) expressed in Hertz by the expression. 1.3. Coherent and non-coherent detection Considering the receiver side, we can classify the demodulation or detection based on the use of the carriers phase information in the process of information recovery. In the case that the receiver uses this information to detect the signals it will be called coherent detection, and non-coherent detection otherwise. This are also called synchronous and asynchronous detection, respectively. Coherent Non-Coherent Phase Shift Keying (PSK) Diferential Phase Shift Keying (DPSK) Frecuency Shift Keying (FSK) Frecuency Shift Keying (FSK) Amplitude Shift Keying (ASK) Amplitude Shift Keying (ASK) Continuous Phase Modulation (CPM) Continuous Phase Modulation (CPM) Figure 3 Non-coherent receiver (Tsimenidis, 2016) Figure 4 Coherent receiver (Tsimenidis, 2016) 2. Non-coherent receiver 2.1. Receiver Front-End This segment of the non-coherent receiver will consist of the first two blocks, which are common for both coherent and non-coherent implementations. Figure 5 Receiver Front-End (Tsimenidis, 2016) The first block is the responsible to take a sampled input expressed as bits, represent it as a float number and then normalise it to a range +/- 1.0. The second stage applies a bandpass filter to the signal, this will attenuate the parasites components of frequency that could contaminate the signal that we received. Figure 6 Frequency response of a passband filter (Tsimenidis, 2016) To design the passband filter we must consider the following information: let = 4800 Hz, data rate = 2400 bps and sampling frequency = 48000 Hz. These assumptions, led us to the following results: Lower passband cut-off frequency: = = 3600 Hz Upper passband cut-off frequency: = + = 6000 Hz Lower stopband cut-off frequency: = = 1200 Hz Upper stopband cut-off frequency: = + = 8400 Hz The implementation of the filter will be done using the sptool command of Matlab, using the above defined values as parameters for the filter. The following figure shows the result obtained in the realization of the lab, considering the number of filter coefficients of 101. Figure 7 Band-pass filter response Figure 8 Band-pass filter input/output 2.2. DPSK demodulator To implement the non-coherent detection, we are going to use a DPSK demodulator, which was previously categorized as a non-coherent technique. The DPSK demodulator will take advantage of two basic operation that occur on the transmitter: the first is the differential encoding, and the second is the phase-shift keying. In the transmitter, the signal will be advanced in phase, with respect to the current signal, if the symbol to be sent is 0, and the phase will be preserved if the bit corresponds to 1. In the side of the receiver, we have memory that will be able to compare the phase of two successive bit intervals, i.e. it determines the relative difference in phase of these two, determining the correspondent symbols without the need of having information about the phase of the signal in the transmitter. Figure 9 Implemented DPSK demodulator (Tsimenidis, 2016) The FIR matched filter block will correspond to a low-pass filter, this is required because the demodulation process, as it is a multiplication between two sinusoidal signals, will generate a low-band signal and a high-band signal, where the second one should be filtered. 2.3. Symbol synchronisation The symbol synchronisation, also called symbol timing, is a critical process that consists in the continuous estimation and update of information of the symbol related to its data transition epochs. This is a critical process that must be conducted to keep the communication accuracy in acceptable levels. Broadly speaking, the synchronization techniques could be classified in two groups: open-loop and closed-loop. The chosen technique for this project corresponds to the Early-Late Symbol Synchronization which is a closed-loop type. The most popular technique is the closed-loop synchronization because Open-loop synchronizer has an unavoidable nonzero average tracking error (though small for large SNR, it cannot be made zero), a closed-loop symbol synchronizer circumvents this problem.(Nguyen Shwedyk, 2009) The corresponding results of the output of the demodulator are the following figures, these corresponds to the signals before and after the signal is filtered with the FIR low-pass filter. Notes: The curve in blue corresponds to the signal containing the high-frequency parasite component, and the curve in red shows the result of filtering the high frequency component, i.e. this is the output signal of the filter. The symbol correspondence is: symbol 0 for positive numbers, and symbol 1 for negative magnitudes. Figure 10 Low-pass filter input/output 2.3.1. Early-late Symbol Synchronization (Reed, 2002) The algorithm Early-late used for synchronization is supported by the idea that the sample of a symbol must be taken in the time where the energy is maximum, this will warranty a minimum error probability. This algorithm exploits the symmetry of the signal, neglecting the distortion and noise. Considering the following figure, we can see that the optimal time to take the sample, identified as T, should be in the halfway between two points T0 + d and T0 d, if the power in the T0 + d and T0 d is, ideally, the same. Figure 11 Optima sample time diagram Suppose the following figure shows a symbol, we can notice that if we take an arbitrary sample, e.g. n=3 and depending on the thresholds, could be wrongly interpreted as 0, however the most appropriated value is 1. Figure 12 Symbol with 40 samples (Tsimenidis, 2016) With a buffer size of 20 registers, we can notice that in the following figure the power levels of the signal for n=0 and n=19 are different, then we need to move the whole buffer one space to the right. Figure 13 Early-Late sample at an arbitrary point (Tsimenidis, 2016) If we continue with the iteration and we follow the rules described in the flow diagram, we will converge in a finite number of iterations, where we can see that the result is located as expected, this could be seen in the following figure. Figure 14 Early-Late sample at the maximum point of power (Tsimenidis, 2016) The results of the application of this algorithm for our case are shown in the following figure: Note: The signal in red is the input of the early-late symbol synchronization block and the signal in blue is the value of Em that will finally determine the value that the symbol is representing, in each case. Figure 15 Early-Late symbol synchronization input/output 2.4. Frame synchronisation As was stated in the in the background section, the message frame will begin with the characters ++++ and the message has 72 bytes encoding the message using a ASCII characters. Therefore, this section will deal with two tasks: (1) Detect the message preamble and (2) Decode byte per byte of the data contained in the payload. After the preamble section, we will detect 576 bits, corresponding to the 72 bytes that correspond to the ASCII characters. These characters will be dumped into an executable file that will then show the message that has been detected and decoded. The specific implementation of the algorithm is attached in the appendix section of this report. 2.5. Results and evaluation The result of applying the steps described in the sections from 2.1 to 2.4, we obtain the message, getting the result showed in the next figure: Figure 16 Result of non-coherent receiver detection 3. Coherent receiver The coherent receiver, also called synchronous receiver, implies certain degree of agreement or knowledge about parameters used in the transmitter side. For the case of the project, we have a signal of type DPSK, i.e. the codification is contained in the variation of the phase of the signal. 3.1. IQ Down-converter The aim of this component is to decompose a complex signal in terms of its in-phase and quadrature elements. To achieve this decomposition, we are going to perform the implementation using lookup-table oscillators, i.e. that for a given signal in-phase and quadrature components will be obtained by using the definitions given by: Figure 17 IQ Downconverter (Tsimenidis, 2016) Upon these definitions, the components that we obtain could be represented in two separated graphs, each one of them representing a different component table. Figure 18 Sine and cosine table graphs As for the index control of look-up table, we decide to use for loop to generate x2I[n] and x2Q[n], storing and transporting data to corresponding files as x2I.h and x2Q.h. These files will be used later to perform the conversion of values. Figure 19 Index control flow (Tsimenidis, 2016) After understanding the principle, we defined all of variables and initialized them to zero inside the main, and select the appropriate value of some variables such as state_mf, coeffs_mf and N_mf.Same as the picture over, the original data from bandpass output is also separated into two filters: Matched Filter I and Matched Filter Q, and the coefficients of the filters are the same with the original one. The benefit of using the lookup-table oscillators (setting x2 into x2I and x2Q) is to decrease the time of simulation because of the lower required sampling rate.ÂÂ   We can use via lookup table method to call them from x2I.h and x2Q.h, so that we can use it more efficiently in Matlab instead of shifting itself. And then, we multiplied x1 to x2I[n] and x2Q[n] one by one by using another for loop and got x3I and x3Q.Besides,the code of matched filter had been given by tutors and got x4I and x4Q. {x4I=fir(x3I,coeff_mf,state_mf_I,N_mf);ÂÂ   //match filter I } {x4Q=fir(x3I,coeff_mf,state_mf_Q,N_mf);ÂÂ   //match filter I } Figure 20 Filter comparison (Tsimenidis, 2016) We monitored and recorded x3I and x3Q in PicoScope and print screen. The wave of them spinning fixed at the origin point so three of these blows were selected to describe this wave batter. Figure 21 Down-conversion: x3I vs. x3Q counter clockwise After this, we can visualize the outputs of each one of the filters, now we are going to plot in the figure x4I and x4Q, obtaining: Figure 22 Down-conversion: x4I vs. x4Q counter clockwise 3.2. Symbol synchronization After IQ down-converter, the next stage is symbol synchronization. To achieve this, we create x5I[n] and x5Q[n] and sent x4I, x4Q one sample at the time. The procedure that we should do in this section is similar to the one seen in the non-coherent detection, however we must consider two buffers instead of one, one for I and other for Q parts. The sum of the above established energies will correspond to the energy that can be seen as the total energy of the signal, which is similar to lab of the symbol synchronization for the non-coherent receiver. The corresponding calculations to obtain the signals after the symbol synchronization process are defined as: Then, plotting the results obtained, we see the following figure: Figure 23 x6I vs. x6Q Due to synchronization problems, we threated the jitter that was causing these inconsistences using the averaging approach, as described in the follows: Figure 24 Averaging approach to overcome the jitter (Tsimenidis, 2016) Figure 25 Code to solve the jitter 3.3. Differential coherent demodulator In this section, we will implement a differential detector, also called a differential coherent demodulator. Figure 26 Principle of the differential detector (Tsimenidis, 2016) At first, we declare and initialize appropriately the required variables and define .In this differential detector, need to multiply ,1 symbol delay by . N N=1 N=2 N=3 After this, we defined x6I_prev and x6Q_prev to deal with this problem and let x6I_prev and x6Q_prev denote the values of x6I and x6Q from the previous symbol. It is very important to initialize them to zero at the declaration because we know . (Tsimenidis, 2016) x6I_prev=x6I; x6Q_prev=x6Q On the same time, dI contains the first two terms which stand for the In-phase part and dQ which contains the last two terms which stand for the Quadrature part. Hard decision is then achieved by deciding whether the dI value is positive or negative, with a negative value indicating that a logic 1 was transmitted which might be used in the next step that is frame synchronization and message detection. Now we obtain the plot showi

The Way It Really Was! :: essays research papers

The Way It Really Was!   Ã‚  Ã‚  Ã‚  Ã‚  In the 1950's there were many problems. The Korean war and the civil rights struggle. Back then the music was all rhythm and blues (r &b). It was record mostly by black artists and for black audience but the white teenagers became interested. The music scene in the early 50's   Ã‚  Ã‚  Ã‚  Ã‚  Before 1954 there were 3 distinct music areas. R & B,country and pop. Music stations usually played one type of music so listeners could easily find what type they wanted. Pop had 4 major recording companies. RCA,Columbia,becca and Mercury. These companies had very good connection and could make a small band very big! Pop music had a subdued beat and smooth singing. R & B had black artists for black audiences. Country Western had the least affect by Rock and Roll. People who recorded at small independent music business and put out a record, they were called Indies. The first Rock and Roll hit   Ã‚  Ã‚  Ã‚  Ã‚  The term Rock and Roll was usually used for describing physical sex. Allen Freed was credited with inventing Rock and Roll but that wouldn't be to good for him later in life. The father of Rock and Roll   Ã‚  Ã‚  Ã‚  Ã‚  Alan freed was the first white disc jockey to play Rock and Roll. Alan show in Cleveland was very popular with teenagers. In 1954, Alan's show moved to WINS. His nick name â€Å"moondog† had to be dropped. He adopted the new title â€Å" the king of rock and roll†. Newspapers ran articles saying Alan was the main wrongdoer in creating Rock and Roll. A riot broke out at one of Alan Freed's concert. The police turned up the house lights to see what the teenagers were doing and Alan said something and the teens went on a rampage. Alan was to blame. He was charged but when the manager at WINS didn't stand behind him, Alan left and went to WABC. The charges were later dropped. Because of all of the court appearances, Alan filed for bankruptcy in 1959. In 1960, Alan was fired from WABC for not signing a statement that he took favors to play certain records. It was all down hill from there. In 1965 Alan died. His friends said that he had a drinking problem and it got worse when he was fired. Adult response to Rock and Roll   Ã‚  Ã‚  Ã‚  Ã‚  Most adults did not like Rock and Roll. They thought it was vulgar and rude. Although there was never a link from violence to teens. Many incidences proved that wrong when Nat King Cole was performing and 5 teens jumped on stage and started to beat up him.