Report on Antenna and base station systems

        From that past data the demand of mobile networks is increasing on daily basis so due to this many mobile communication systems has been introduced from the last few years. Base station is a powerful equipment that is placed at specific location for managing and controlling the operation of million calls on daily basis, due to this reason a huge number of antennas and bas stations are required to support the users of mobile network. The subsystem of base station depends on two types in which one is base station controller and the second is base transceiver station.

        A BTS location consist of four main parts that are towers between 25 to 75 meters for the antennas, BTS machine. Power source and power amplifier, where the data transmission and receiving of radio frequency signals occurs. Between 1 to 16 transceivers, each BTS serves as one cell that are installed in the cover area depending on the user density. This research is completely depend on the BTS site and include all type of information just like BTS machine 

B. For GMS the Base transceiver station and Antenna and base station systems

            The infrastructure of BTS consist of user devices connected like computers and mobile phones to the network of operators. In the global system for GSM, this type is normally used for a 2G network. It include antennas to send the signals to the wanted source and towers with transceivers to receive the signals from different resources that is already mentioned in the introduction. One of the main functions of BTS is making sure hopping signals are cancelled out so that on the same frequency no two signals hop.

        Signals passes through the BTS machine where different processes occurs like modulation/demodulation, multiplexing, encryption/decryption and speech encoding and decoding. As we know voice is depend on analog signals and GSM is a digital system so this process must be done. This is done with the help of encoding and decoding that signals need to be converted into digital signals before move through antennas and back to receiver to AC. Between the mobile system, BTS and Air interference, the encryption process is used for the security of users and done only for the connection. To minimize the number of antennas needed, this can be done through just multiplying and combine them together for making it single signal. After the encoding process, modulation is normally done to assign amplitude values for the data encoded and after that again trough source going to be demodulate. While the signals are being transmitted, this process is normally used to minimize the out of band interference.

        For receive and sends signals, the BTS antennas are going to used as components. With gain between 15 to 21 dB, typical antennas are about 1 to 2 meters long. The antennas are connected with the help of 50 W coaxial cable and from the BTS this should be not located more than 100 meters away.  Throughout the years there are many types of antennas are going to used but for mobile communication the most common  type used in the GSM network are the Omni directional and directional antennas used in the system.

C. For LTE eNode B of Antenna and base station systems

        For even high speed wireless communication, long term evaluation was created in the current years. In the LTE architecture, using the SI interface and not included a controller and this controller is quite near to the base station and connected with main network unlike the GSM and UMTS. Evolved Node B is known as the base station for LTE that include more than one eNode B and placed in the E-UTRAN. By using the X2 interference, different eNode b’s are connected together. The function of controller are performed and separated by eNode CN and B because of the absence of the RNC equivalent through this network. By the Uu interference, through this connection between the two nodes are represented in proper way.

        6 sectors handled by the eNode B and with this, 3 antennas are appointed at each sector. For both the download link and uplink procedures, for designing there are different antennas are used. The procedure from uplink is done with the help of MUX that contain single input and many outputs, and downlink procedure is done by the multiple inputs multiple output antennas. Bandwidths starting from the 5 MHz to 20MHz with 5 MHz difference for each and work done with eNode B.

D. For UMTS Node B of Antenna and base station systems

        After the development of BTS throughout the year and then to support the Universal mobile telephone system 3G wireless network, Node B was created. This just like BTS but having different name. there are different Universal terrestrial radio access network that contain more than Node Bs but there is only one radio controller is present and all of these are involved in making the radio network subsystem and UMTS use this system. One or more RNSs are included in the UTRAN system.  The main function of node b is to transfer the data flow between the RNC and user equipment, respectively with Uu and Iub interference.

        power control and spreading/dispreading control. In the spreading function, the signals are going to spread with large bandwidth into a larger wideband signal then the narrowband signals originally and in dispreading process the wideband signals are converted back to original form of signals. This complete process is going to used to decrease the interference to other random receivers and to increase privacy of the users. For measuring the single interface ratio from those signals that are transmitted from UE, this can be done through inner loop power control and it is also called fast power control. This process is important because through this the signals coming from near and far are maintained easily. For measuring this signal the power control is decreased in the start and after this it is increased.

            With the help of Multimedia file, the block can be constructed easily and simulations are performed through uploading audio files.  From analogue o digital the audio file should be converted and by using the uniform encoder this process will be done which quantize the input into required number of bits and move to integer of bit converter. It is the transmission end and both blocks collectively act as an analog to digital convertor. The signals should be converted back to an analogue signals when the signals then reach the receiving and this process will be completed by the inverse of blocks send in the first place that work as digital to analogue converter for the signals. Where Bit to integral convertor and uniform decoder, the block is used to act like a DAC. At the end, the signals are going to reached to audio device writer in this the audio can be used again. From this the quality of the audio signal can be determine easily. Both of these signals are constructed in the same figure.

        There is a use of software for plotting the graphs and this can be done through MATLAB. This is because it is using bit number like 2, 4, 8 and 16 bit accordingly. For storing the input data a proper script is written, and can be used for plotting graphs. The data is stored in two workspace files and can be transferred to blocks.  Due to quantization noise, the receiving signal is involved in using 2 and 4 bits but this data is not like the exact data from the transmitted signal. The reason is that there is only one problem quantization level is extremely 

            For the voice telephony between 128-256 are required by the number of quantization levels needed. Because the transmitting signals there are number of bits are present in the data that are involved in optimizing the data in proper way. Through this the signal is transfer in proper way and clear voice is obtain. In the given table the number of quantization levels using the equation the 2, 4,8and 16 bits calculated. In equation L is the number of quantization levels and number of bits represented by m. this table also explain that as the level of quantization are 256 the 8 bit transmitter for voice telephoney will be enough and for 16 bit transmitter the 65536 that is more than the requirement happen for this type of transmission.

        If to increase the power of the signal maximum power is needed to achieve required level so transmitting data from 8 bit to 16 bit will be cheaper, as observations says this.

        The energy per bit to noise ratio against Bit Error Rate is plotted finally, and without consideration bandwidth restrictions without considering MATLAB produced by theoretical Results were compared to the results taken by simulations. For 2,4,8 and 16-PAM the simulations have been included by the Plot. The most stable curve in Figure B-7 is the 2-PAM the plot includes the simulations, and for all the other simulations an average power of 1 W has been used. AS it needed to be performed on least E/N capacity for the production of most transmission capacity.

 References of Antenna and base station systems

 B.  Lindmark and C.  Beckman, "The evolution of base station antennas for mobile communications", 2007 International Conference on Electromagnetics in Advanced Applications, 2007.

 M.  Adhikari, "A Survey and Review of GSM Base Transceiver System Installation, Architecture and Uplink/Downlink", Jawaharlal Nehru Technological University, Kakinada, A.P, India, 2015.

 A.  Mehrotra, GSM system engineering, 1st ed. Boston: Artech House, 1997, pp. 43-46.

J.  Scourias, "Overview of the Global System for Mobile Communications", University of Waterloo, 1995.

R.  Sutton, Secure communications, 1st ed. Chichester: John Wiley & Sons, Ltd., 2001, p. 177.

 A.  Toskala and H.  Holma, WCDMA for UMTS: HSPA Evolution and LTE, 1st ed. Wiley, 2010, pp. 67-72.

S.  Kasera and N.  Narang, 3G Networks, 1st ed. New Delhi: Tata McGraw-Hill Education Private, 2012, pp. 90-91.

B.  Furht and S.  Ahson, Long Term Evolution, 1st ed. Boca Raton, FL: CRC Press/Taylor & Francis, 2009, p. 138.

K.  Watanabe and M.  MAchida, "Outdoor LTE Infrastructure Equipment (eNodeB)", FUJISTU Sci. Tech. J., vol. 48, no. 1, 2012.