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Question: Discuss About The Reception Or End Point Signal Transmission? Answer: Introducation Antennas: these are devices that propagate electromagnetic signals to or from electronic circuits using either conducting wires or conducting apertures. These devices are usually at the forefront of signal reception or end point of signal transmission. Furthermore, based on their design structure and propagation pattern, antennas are usually classified into three major categories; directional antennas, semi-directional antennas and Omni-directional antennas. Now, directional antennas usually propagate signals in one specific direction which improves their gain and directivity properties. Example Yagi Uda (Yagi) and Horn antenna. Semi-directional antennas, on the other hand, have their transmissions restricted in certain directions. Examples; patch and panel antennas. Finally, Omni-directional antennas that propagate signals in all directions. Example cellular antennas (MIT, 2004). Yagi antenna serving either as a directional or semi-directional antenna, Yagi antenna is one of the most common antenna used in the market having the ability to propagate RF waves in specific direction facilitated by high gains. Applications; Televisions set receivers. Strengths High gains that facilitate long distance transmission. Good directivity because of the design that focuses signals in one specific direction having a high gain. Simple to design and install, as they are made of simple metallic rods(radio-electronics, 2017). Horn antenna another good example of directional antennas but with higher gains and directivity levels. Due to these attributes, horn antennas are used to propagate electromagnetic signals with high frequencies i.e. UHF (Ultra-high frequencies ranging from 300MHz to 3 GHz). In addition to this, horn antennas are designed with a horn like structure where a significant aperture flares out at the end of the device. Application, transmission of microwaves signals.Horn antennas are designed with the attributes of gain and directivity in mind. This outcome is facilitated by their aperture structure that improves their gains tremendously. Secondly, horn antennas can operate with a wide range of frequencies and bandwidth. Requires extended lengths to operate effectively. Complex to design and install(Rouse, 2017). Cellular antenna the only Omni-directional antennas considered in this case, thus has the ability to propagate RF signals in all directions. However, this ability limits its gains and directivity outcomes (Carr, 2012). Nevertheless, its convenient for mobile devices thus is used in portable gadgets such as phones, tablets and even vehicles.For their size and design structure, cellular antennas have optimal boosting capability. Secondly, they are able to operate in all directions.Cellular antennas have minimal gains. Moreover, they have a short coverage distance. Future prospect for medium and long-distance application In this context (coverage distance) directional and sometimes semi-directional antennas are the best for the job as they focus the signal being transmitted (received) to the appropriate destination (source). Therefore, the future of wireless technology will rely on the same devices to accomplish the goal of transmitting RF signals across medium sized distances and beyond. However, these antennas maybe modified to fit the need for smart systems where the structure and design of Omni-directional antennas maybe incorporated(Carr, 2012). Multiple access protocols/techniques Multiple access techniques provide the users with the ability to use common communication channels to transmit their signals. These techniques help to optimise the available bandwidth which helps in resources allocations. Therefore, regardless of the technique adopted (CDMA or FDMA), the objective is always the same, that of sharing a common radio spectrum (corps, 2000). Furthermore, the same technique will enable users to share the capacity of communication channels while operating in different locations. In addition to this, the operational structure of the said techniques is always designed to avoid interferences, an outcome that designates the mode of transmission used. Type 1: CDMA (Code division multiple access) In this technique, unique pseudo codes are used to share the communication channel among the signals or users involved. In terms of operation, these codes are used as unique identifiers for the signals found in the communication channel, thus they act as identification tags. Now, these tags are usually attached at the onset of communication before, the signals are propagated into the channel being used. At the reception stage, the tags (codes) are again used to separate the signals thus transforming the signals into unique components as initially transmitted. A good example of this technique is the IS-95 standard, a CDMA standard that uses 64 Walsh code to transmits multiple signals under a common channel(corps, 2000). Type2: FDMA (Frequency division multiple access) as the name suggests, FDMA uses an array of frequency channels to transmit multiple signals on a common channel. Now, to start the transmission process, the frequency channels chosen must be unique i.e. non-overlapping to avoid signal interference either during transmission or at the reception stage. However, unlike the codes of the CDMA, the reception can fail to know the frequencies being used as the channel is usually segmented by the frequency channels chosen. Example; the technique is used in GSM communication where a 25MHz frequency channel is usually divided into 124 carrier sections. CDMA FDMA The frequency is common throughout the transmission process irrespective of the signals considered. The communication channel is split into different sections based on the frequency. Users/signals are uniquely identified by pseudo-codes. There are no unique identifiers used to signify the user/signals as unique channel segments are used. For effective communication, the receivers must know the codes of the transmitting devices. This attribute is not necessary for FDMA. For every signal transmitted, the receivers will only detect the necessary code while identifying the rest as noise Reception of signals is based on the frequency channels chosen. - FDMA will use filtering to eliminate interferences e.g. noise The overall concept is based on unique identification codes. A narrow range of frequency band is used. (Zahra, 2015) References Carr, J. (2012). Directional or Omnidirectional antenna? Joe Carr's Radio Tech-notes, Retrieved 14 August, 2017, from: https://www.dxing.com/tnotes/tnote01.pdf. corps, W. (2000). FDMA vs. TDMA vs. CDMA. Connecting Wireless, Retrieved 14 August, 2017, from: https://wirelessapplications.com/pdf/lf/FD_TD_CDMA.pdf. MIT. (2004). Chapter 3: Antennas. MIT, Retrieved 17 August, 2017, from: https://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-661-receivers-antennas-and-signals-spring-2003/readings/ch3new.pdf. radio-electronics. (2017). Yagi Antenna / Yagi-Uda Antenna. Antennas and propagation, Retrieved 14 August, 2017, from: https://www.radio-electronics.com/info/antennas/yagi/yagi.php. Rouse, M. (2017). Horn antenna. Research gate, Retrieved 17 August, 2017, from: https://searchmobilecomputing.techtarget.com/definition/horn-antenna. Zahra. (2015). FDMA-TDMA-CDMA. Multiple access techniques in wireless communication, Retrieved 16 August, 2017, from: https://www.slideshare.net/SammarKhan2/fdmatdmacdma.