The main object of this project is to make a testbed for MIMO-OFDM antenna 4G technology, we are using MIMO instead of SISO (conventional systems uses one antenna at both transmitting and receiving ends) or MISO, because of its robust nature then that of the others, as it give very good QOSs( Quality Of Services) at very high data rate, this is based on the Theory of Characteristics Modes(TCM) which identify the different modes of radiations of antenna, by properly choosing the modes of radiations. The Theory of Characteristics Modes help us to obtain the radiations pattern of arbitrarily-shaped metallic structure. The radiations patterns, not only present really attractive orthogonal properties, but also bring physical insight into the radiating phenomena taking place on the antenna. For the MIMO-OFDM the first part was to make a hardware part in which we used 3 antennas at the receiving end and transmitting end both, we are using aurduino as a microprocessor , and the second part will be software. 1.1 HARDWARE PART: In the Hardware our first step was to select different components, following is the list of the components we are using in our project:· Aurduino 2560 Microprocessor· Zigbee 2530 Module· MAX 232· Digital Humidity and Temperature (DHT)· LCD 16*2· Crystal Oscillator 16MHZ· Regulator 7805· Capacitors· Resistors· Inductors· Diodes· LEDs 1.
1.1 AURDUINO DUE MICROPROCESSOR:Aurduino is an open-source electronics platform based on very simple hardware and software. Aurduino circuit boards are able to read inputs light on a sensor, a finger on a button, or a Facebook message and turn it into an output activating a motor, turning on an LED, publishing something online. You can tell your board what to do by sending a set of instructions to the microcontroller on the board. To make possible all these things you use the Aurduino programming language (based on connections), and the Software of Aurduino (IDE), it is entirely based on processing..In our project DUE model is used ,because it is more efficient and fast for processing.
It is used when more memory is required, more pins of Input and Output, more sketch memory and RAM. Aurduino DUE is programmed with the Aurduino Software, the Integrated Development Environment the software is common in all of the boards and runs online and offline as well. With 54 pins for digital I/O, and 16 analog inputs and a more space for the sketch. This provides projects larger room and opportunities for maintaining the performance of the Aurduino at any platform. We will show in the software part that how to connect the Aurduino board to the computer and upload our first sketch.1.
1.2 ZIGBEE 2530 MODULE:ZigBee is an IEEE 802.15.4 based, low power, low data rate supporting wireless networking standard, which is basically used for two-way communication between sensors and the controller.
It is a low range communication standard like Bluetooth or Wi-Fi, covering range from 10 to 100 meters. The difference being while Bluetooth and Wi-Fi are high data rate communications standard supporting transfer of complex structure like media, software etc. ZigBee Technology supports transfer of simple data like that from sensors. It supports low data rate of about 250 kbps. The operating frequencies are 868 MHz, 902 to 928 MHz, 2.4 GHz. ZigBee is used mainly for the systems requiring low power, less costly, lower data rate and longer battery life.
In this project, 2530 module of zigbee is being used ,which more reliable as compared with other module and provide high data capacity. Below are the features with also specifications for 2530 module.1.1.
2.1 FEAUTERS:· It is easier as other UART modules· Sending larger data packets and fast broadcasting via UART· Programming is done through UART (a Bootloader, and serial module is required)· Configuration through high computer software· Auto networking (required one router and onecoordinator atleast )· Real time signal monitoring intensity between Router, Coordinator and the Devices.1.1.2.2 SPECIFICATIONS:· Onboard chip: CC2530F256RHAR· Communication distance : wide and open environment· Absolute maximum: over 350 meters· Stable communication: over 250 meters· Frequency range: 2.
4GHz· Wide supply-voltage range (2 V–3.6 V)· Operating temperature: -40? ~ 85?· Serial port baudrate: 38400bps (default), different baud rates are available by software configuration· Antenna: 2.4G 2DB 360° Omni-directional 1.
1.3 MAX 232:MAX 232 is kind of IC. It is created by maxim integrated products. It converts signals from the serial ports into the digital logic circuits. It is a dual mode IC means it can receive or deliver the signals and perform desired functions on it.
1.1.4 CRYSTAL OSCILLATOR:An oscillator is a kind of electronic circuit that uses the mechanical reverberation of a vibrating stone of piezoelectric material for making an electrical flag with extremely same recurrence.
The recurrence normally used for monitoring the time, for give a stable clock flag for computerized coordinated circuits, and for balancing out the frequencies for transmitting and beneficiaries in radio. The well known kind of piezoelectric resonator utilized is the quartz precious stone, oscillator circuits consolidating those ended up as known oscillators but other piezoelectric materials including polycrystalline ware production are by utilized as a part of comparable circuits. 1.1.5 DIGITAL HUMIDITY AND TEMPERATURE DEVICE (DHT):It will provide readings of ourdata transmission by the means of temperature reading. We use this device for testing purpose only we can also remove it when no longer needed.
1.1.6 REGULATOR 7805:This regulator converts the 12vol t to 5 volt which is suitable for aurduinoand LCD device attach to it. This regulator is a part of our power supply.7805 series ICs have built-in protection against a circuit drawing too much power. They have protection against overheating and short-circuits, making them quite robust in most applications.
In some cases, the current-limiting features of the 7805 devices can provide protection not only for the 7805 itself, but also for other parts of the circuit.1.1.7 DIODES:A diode is basically device which give low resistance in one direction and high resistance in other direction. A very small amount of current in either way forward or backward flow run in the diode, because diode is reverse biased or forward bias depend on its type.
A diode is a two terminal device In this project we use multiple diodes connected in series which has the function of rectify. In this project we use it only for safety purpose. It converts AC to DC.
1.1.8 CAPACITORS:A capacitor is basically an electrical component which have an ability to store electric charges. It filters the noise in Ac signal.
A capacitor is basically passive electrical component and it is two terminal. It store electrical charges in the form of potential energy. Capacitors and batteries both work in different way but they both store electrical charges. It is much like a small rechargeable battery.1.1.9 RESISTERS:A resister is an electrical device that is used to produce resistance again the electrical charges.
Resisters are passive electrical components. 1.2 BASIC BLOCK DIAGRAM OF MIMO: 1.
2.1 SENDING END:At sender end, bitdata rata converted into M parallel data stream after serial-to-parallel streams, so as to realize the multiple antennas at the output. For each path flow, we first do the signal mapping then IFFT transform. IFFT transform realize OFDM modulation functions here. Thefunction is that low-speed of multi-channel parallel data flow are modulated to mutually orthogonal K sub-carrier at the same time. For reducing the ISI, the interval is protected that usually use circle prefix form is joined in among symbols after IFFT. At last, the data stream is transmitted after parallel-to-serial conversion.
1.2.2 RECEIVING END:In the receiver, each antenna received signals that were sent by M transmitting antennas and MIMO channel linear superposition. The system first desterilizes and removes circulation of prefix from each data stream then according to receiving antenna the FFT transformation, from the time domain transform to frequency domain. At last, parallel data flow is delivered to modem after detector processing and get recovery information bit streams by serialize. 1.3 SOFTWARE PART:For the software part we simply applying codes in aurduino using aurduino IDE. We do it because we want our RF module to send data and then receive it simultaneously Our first step starts with installing the aurduino.
To do so go to your web browser and search for aurduino IDE as shown in the Figure 4.2. After search open the first link. Then click the windows hyperlink in the portions by build Beta as shown above in the figure. After clicking they ask you to download as shown below the figure just download it and after it is download you are ready for going.For the last we have to develop an environment for our coding and to match it with the version of aurduino we are using to do so go to tools option in the aurduino software and then click aurduino DUE board and, in the section of all the latest version of aurduino board select your version of aurduino for example Aurduino Due as tAfter these processes it is ready to make the programming in this environment.
Because of its simple and accessible experience, Aurduino has been accessible in thousands different projects and applications. Aurduino software is easy-to-use for the beginners, yet flexible enough for any advanced users. And it runs on Mac, Windows, and Linux. Either Teachers or students uses it as to develop low cost instruments, to prove any of the scientific and physics principles, or to start with the programming and robotics. There are many other microcontrollers and microcontroller platforms available for physical computing. Parallax Basic Stamp, Netmedia’s BX-24, Phidgets, MIT’s board, and many other may offers similar functions. These tools then take the specific details of the microcontroller’s programming and make it in a very easy-to-use package. Aurduino can also simplifies the process for working with the microcontrollers, but it also offers some of the advantages for study purposes and interested peoples over other useable systems
