Adaptive Techniques in Advanced 4G Cellular Wireless Networks By

ISSN 2319-8885 Vol.06,Issue.16 April-2017,

Pages:3002-3007

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Adaptive Techniques in Advanced 4G Cellular Wireless Networks by using 8 * 8 Antennas 1 2 KAREEM MOHAMMED YASEEN AL.SAUDI , B.BHASKARA RAO 1PG Scholar, Acharya Nagarjuna University, Andhrapradesh, India, E-mail: [email protected]. 2Assistant Professor, Dept of ECE, Acharya Nagarjuna University, Andhrapradesh, India, E-mail:[email protected].

Abstract: The ability of 4G mobile wi-fi networks like long time Evolution advanced may be extended by means of large bandwidth for multicarrier operation, better quantity of antennas for extra spatial multiplexing, tighter reuse of radio cells the use of the same frequency spectrum and optimization of the community configuration in popular. The potentially better capability might be performed most effective if the entire wi-fi community can be more or less perfectly tailored to the current real environment at any time. This actual environment which incorporates as an example the radio channel, the user visitors, the gadget performance and the community configuration can exchange, but, inside a time scale of a wide variety from under 1 ms up to more than a hundred s. suitable linear or nonlinear adaptive strategies that are able to track those changes are defined for wideband linear power amplifier, a couple of input multiple(8*8) output antenna structures, heterogeneous networks and self- organising networks which includes the corresponding realisation and overall performance aspects.

Keywords: Wireless Networks, Wi-Fi Community, GSM, GPRS, TDMA.

I. INTRODUCTION the evolution of GSM to GPRS, using the same air interface A. LTE Overview and access method, TDMA (Time Division Multiple LTE (Long Term Evolution) or the E-UTRAN (Evolved Access). To reach higher data rates in UMTS (Universal Universal Terrestrial Access Network), introduced in 3GPP Mobile Terrestrial System) a new access technology R8, is the access part of the Evolved Packet System (EPS). WCDMA (Wideband Code Division Multiple Access) was The main requirements for the new access network are high developed. The access network in UMTS emulates a circuit spectral efficiency, high peak data rates, short round trip switched connection for real time services and a packet time as well as flexibility in frequency and bandwidth. switched connection for datacom services (black in figure 1). In UMTS the IP address is allocated to the UE when a datacom service is established and released when the service is released. Incoming datacom services are therefore still relying upon the circuit switched core for paging. The Evolved Packet System (EPS) is purely IP based. Both real time services and datacom services will be carried by the IP protocol. The IP address is allocated when the mobile is switched on and released when switched off. The new access solution, LTE, is based on OFDMA (Orthogonal Frequency Division Multiple Access) and in combination with higher order modulation (up to 64QAM), large bandwidths (up to 20 MHz) and spatial multiplexing in the downlink (up to 4x4) high data rates can be achieved. The highest theoretical peak data rate on the transport channel is 75 Mbpsin the uplink, and in the downlink, using spatial multiplexing, the rate can be as high as 300 Mbps. Figure1. Network Solutions from GSM to LTE.

The LTE access network is simply a network of base GSM was developed to carry real time services, in a stations, evolved NodeB (eNB), generating a flat architecture circuit switched manner (blue in figure 1), with data services (figure 2). There is no centralized intelligent controller, and only possible over a circuit switched modem connection, the eNBs are normally inter-connected viathe X2-interface with very low data rates. The first step towards an IP based and towards the core network by the S1-interface (figure 2). packet switched (green in figure 1) solution was taken with

KAREEM MOHAMMED YASEEN AL.SAUDI, B. BHASKARA RAO The reason for distributing the intelligence amongst the 1 GHz. This bandwidth is divided up into 6-MHz wide base-stations in LTE is to speed up the connection set-up and channels. Initially, one TV station or channel used a single reduce the time required for a handover. For an end-user the 6-MHz band. But with digital techniques, multiple TV connection set-up time for a real time data session is in many channels may share a single band today thanks to cases crucial, especially in on-line gaming. The time for a compression and multiplexing techniques used in each handover is essential for real-time services where end-users channel. This technique is also used in fiber optic tend to end calls if the handover takes too long. communications systems. A single fiber optic cable has enormous bandwidth that can be subdivided to provide FDMA. Different data or information sources are each assigned a different light frequency for transmission. Light generally isn’t referred to by frequency but by its wavelength (λ). As a result, fiber optic FDMA is called wavelength division multiple access (WDMA) or just wavelength division multiplexing (WDM). One of the older FDMA systems is the original analog telephone system, which used a hierarchy of frequency multiplex techniques to put multiple telephone calls on single line. The analog 300-Hz to 3400-Hz voice signals were used to modulate subcarriers in 12 channels from 60 kHz to 108 kHz. Modulator/mixers created single sideband (SSB) signals, both upper and lower sidebands. These subcarriers were then further frequency multiplexed on subcarriers in the 312-kHz to 552-kHz range

Figure2. X2 and S1 Interfaces. using the same modulation methods. At the receiving end of the system, the signals were sorted out and recovered with Another advantage with the distributed solution is that the filters and demodulators. Original aerospace telemetry MAC protocol layer, which is responsible for scheduling, is systems used an FDMA system to accommodate multiple represented only in the UE and in the base station leading to sensor data on a single radio channel. Early satellite systems fast communication and decisions between the eNB and the shared individual 36-MHz bandwidth transponders in the 4- UE. In UMTS the MAC protocol, and scheduling, is located GHz to 6-GHz range with multiple voice, video, or data in the controller and when HSDPA was introduced an signals via FDMA. Today, all of these applications use additional MAC sub-layer, responsible for HSPA scheduling TDMA digital techniques. was added in the NB. The scheduler is a key component for the achievement of a fast adjusted and efficiently utilized C. TDMA radio resource. The Transmission Time Interval (TTI) is set TDMA is a digital technique that divides a single channel to only 1ms. or band into time slots. Each time slot is used to transmit one byte or another digital segment of each signal in sequential B. FDMA serial data format. This technique works well with slow FDMA is the process of dividing one channel or voice data signals, but it’s also useful for compressed video bandwidth into multiple individual bands, each for use by a and other high-speed data. A good example is the widely single user (Fig3). Each individual band or channel is wide used T1 transmission system, which has been used for years enough to accommodate the signal spectra of the in the telecom industry. T1 lines carry up to 24 individual transmissions to be propagated. The data to be transmitted is voice telephone calls on a single line (Fig4). Each voice modulated on to each subcarrier, and all of them are linearly signal usually covers 300 Hz to 3000 Hz and is digitized at mixed together. an 8-kHz rate, which is just a bit more than the minimal Nyquist rate of two times the highest-frequency component needed to retain all the analog content.

Fig3.

The best example of this is the cable television system. Fig4. The medium is a single coax cable that is used to broadcast hundreds of channels of video/audio programming to homes. The digitized voice appears as individual serial bytes that The coax cable has a useful bandwidth from about 4 MHz to occur at a 64-kHz rate, and 24 of these bytes are interleaved, producing one T1 frame of data. The frame occurs at a International Journal of Scientific Engineering and Technology Research Volume.06, IssueNo.16, April-2017, Pages: 3002-3007 Adaptive Techniques in Advanced 4G Cellular Wireless Networks by using 8 * 8 Antennas 1.536-MHz rate (24 by 64 kHz) for a total of 192 bits. A signals can occupy the same channel simultaneously. For single synchronizing bit is added for timing purposes for an example, using 64 unique chipping codes allows up to 64 overall data rate of 1.544 Mbits/s. At the receiving end, the users to occupy the same 1.25-MHz channel at the same individual voice bytes are recovered at the 64-kHz rate and time. At the receiver, a correlating circuit finds and identifies passed through a digital-to-analog converter (DAC) that a specific caller’s code and recovers it. The third generation reproduces the analog voice. The basic GSM (Global System (3G) cell-phone technology called wideband CDMA of Mobile Communications) cellular phone system is (WCDMA) uses a similar method with compressed voice TDMA-based. It divides up the radio spectrum into 200-kHz and 3.84-Mbit/s chipping codes in a 5-MHz channel to allow bands and then uses time division techniques to put eight multiple users to share the same band. voice calls into one channel. Figure 3 shows one frame of a GSM TDMA signal. The eight time slots can be voice A. OFDMA signals or data such as texts or e-mails. The frame is OFDMA is the access technique used in Long-Term transmitted at a 270-kbit/s rate using Gaussian minimum Evolution (LTE) cellular systems to accommodate multiple shift keying (GMSK), which is a form of frequency shift users in a given bandwidth. Orthogonal frequency division keying (FSK) modulation. multiplexing (OFDM) is a modulation method that divides a channel into multiple narrow orthogonal bands that are spaced so they don’t interfere with one another. Each band is divided into hundreds or even thousands of 15-kHz wide subcarriers. The data to be transmitted is divided into many lower-speed bit streams and modulated onto the subcarriers. Time slots within each subchannel data stream are used to Fig5. package the data to be transmitted (Fig. 5). This technique is very spectrally efficient, so it provides very high data rates. D. CDMA It also is less affected by multipath propagation effects. CDMA is another pure digital technique. It is also known as spread spectrum because it takes the digitized version of an analog signal and spreads it out over a wider bandwidth at a lower power level. This method is called direct sequence spread spectrum (DSSS) as well (Fig. 4). The digitized and compressed voice signal in serial data form is spread by processing it in an XOR circuit along with a chipping signal at a much higher frequency. In the cdma IS-95 standard, a 1.2288-Mbit/s chipping signal spreads the digitized compressed voice at 13 kbits/s.

Fig7.

To implement OFDMA, each user is assigned a group of subchannels and related time slots. The smallest group of subchannels assigned is 12 and called a resource block (RB). The system assigns the number of RBs to each user as needed. Fig6. B. Multiple-Antenna Techniques II. SPREAD SPECTRUM IS THE TECHNIQUE OF As discussed above, transmission and reception techniques CDMA for multiple-antenna systems can roughly be divided into The compressed and digitized voice signal is processed in spatial multiplexing techniques, spatial diversity techniques, an XOR logic circuit along with a higher-frequency coded and smart antenna techniques (see Fig. 5 for an overview of chipping signal. The result is that the digital voice is spread the various techniques discussed in the previous sections). In over a much wider bandwidth that can be shared with other addition to this classification, there are other options for users using different codes. The chipping signal is derived categorizing multiple-antenna techniques: SIMO, MISO, and from a pseudorandom code generator that assigns a unique MIMO techniques Transmission techniques for multiple- code to each user of the channel. This code spreads the voice antenna systems can be distinguished according to the signal over a bandwidth of 1.25 MHz. The resulting signal is number of transmit and receive antennas used. Techniques at a low power level and appears more like noise. Many such that only utilize multiple receive antennas (such as diversity

International Journal of Scientific Engineering and Technology Research Volume.06, IssueNo.16, April-2017, Pages: 3002-3007

KAREEM MOHAMMED YASEEN AL.SAUDI, B. BHASKARA RAO reception schemes [4]) are referred to as single-input knowledge at the transmitter (such as the transmitter-sided multiple output (SIMO) techniques in the literature. beamformingtechniques [5] or the limited feedback schemes Similarly, techniques that utilize multiple transmit antennas [148], [149] discussed in Section IV) are called closed-loop only are called multiple-input single-output (MISO) techniques. Finally, transmission techniques that require techniques. Finally, techniques that require multiple neither channel knowledge at the transmitter nor at the antennas at both ends of the wireless link (e.g., spatial receiver side are called non-coherent techniques. For multiplexing techniques such as the BLAST scheme [1]) are example, the differential space-time transmission techniques called multiple-input multiple-output (MIMO) techniques. [118]-[120] discussed in Section III-H are an important class Narrowband and broadband techniques Transmission of non-coherent multiple-antenna techniques. Co-located and techniques that are designed for frequency flat fading distributed MIMO systems In a conventional MIMO system, channels are called narrowband techniques. For example, the antennas at transmitter and receiver are part of some sort OSTBCs [55] or the original BLAST scheme [1] are typical of antenna array (co-located MIMO system). In contrast to narrowband techniques. In contrast to this, transmission this, antennas can also be spatially distributed on a large techniques that are suitable for frequency-selective fading scale (distributed MIMO system). Examples include virtual channels (e.g., multipleantenna techniques that are based on MIMO systems employing a distributed space-time coding OFDM) are referred to as wideband or broadband scheme [134]-[137], cf. Section III-J. Single-user and techniques. multiuser MIMO techniques Finally, one can distinguish between single-user and multiuser MIMO techniques, either for broadcast scenarios or for multiple-access scenarios. The above discussion has shown that the various multiple antenna techniques available in the literature are quite diverse, in terms of their specific requirements and objectives.

C. AMC Albanian Mobile Communications Sh.A. (AMC) was a telecommunications company that operated in Albania for 19 years. AMC has been part of the COSMOTE Group since 2000 and in 2008 joined the Deutsche Telekom group. Since July 2015, the company is operating as Telekom Albania. When COSMOTE acquired AMC, the company had 11,000 subscribers actually making outgoing calls.[3] In December 2001 AMC customer base exceeded 273,000 customers and in 2009 it had reached a customer base of 1.9 million.

Fig8. Open-loop, closed-loop, and non-coherent techniques Transmission techniques for multiple-antenna systems that Currently, the company’s network covers 99.6% of require no channel knowledge at the transmitter side are thepopulation and 95% of the geographical area However, in referred to as open-loop techniques, because no feedback of 2011 its customer base retreated to 1.8 million. In 2011 channel state information from the receiver to the transmitter AMC entered in the Albanian landline market, the second is required. For example, space-time coding techniques and company in Albania that offers landlines in all country. spatial multiplexing techniques such as the BLAST scheme AMC was the second mobile operator that provides 3G [1] are typical open-loop techniques. In contrast to this, technology in Albania. On September 2011 the Albanian transmission techniques that require full or partial channel government awarded the second 3G network license to AMC International Journal of Scientific Engineering and Technology Research Volume.06, IssueNo.16, April-2017, Pages: 3002-3007 Adaptive Techniques in Advanced 4G Cellular Wireless Networks by using 8 * 8 Antennas for € 15.1 million ($20.6 million) outbidding Eagle detection, which is the 3GPP LTE Rel. 8 flagship feature.[3] Mobile which offered 12.9 million euros.On January 2012 Newly added base stations should be self-configured in line AMC Launched 3G services in Albania, only 3 months with a "plug-and-play" paradigm while all operational base following the 3G license acquisition. On June of the same stations will regularly self-optimize parameters and year AMC 3G infrastructure extended to approximately 95% algorithmic behavior in response to observed network of the country. By upgrading its service with the 3G performance and radio conditions. Furthermore, self-healing platform, AMC has fulfilled another technological milestone mechanisms can be triggered to temporarily compensate for in its history. AMC has fulfilled the HSPA(Evolved High- a detected equipment outage, while awaiting a more Speed Packet Access) standard, aiming to provide its permanent solution. subscribers with the same quality of service in different areas F. WLPA of the country. WLPA (1490 AM, "ESPN Radio 92.7") is a commercial

AM radio station licensed to serve Lancaster, Pennsylvania. D. MIMO The station is owned by Hall Communications and In radio, multiple-input and multiple-output, or MIMO is simulcasts the sports programming of sister station WONN- a method for multiplying the capacity of a radio link using FM. WLPA is one of Pennsylvania's oldest radio stations. multiple transmit and receive antennas to exploit multipath propagation.[1] MIMO has become an essential element of G. HETNET wireless communication standards including IEEE 802.11n A heterogeneous network is a network connecting (Wi-Fi), IEEE802.11ac (Wi-Fi), HSPA+ (3G),WiMAX(4G), computers and other devices with different operating and Long Term Evolution (4G). More recently, MIMO has systems and/or protocols. For example, local area networks been applied to power-line communication for 3-wire (LANs) that connect MicrosoftWindows and Linux based installations as part of ITU G.hn standard and HomePlug personal computers with Apple Macintosh computers are AV2 specification.[2][3] At one time, in wireless the term heterogeneous. The word heterogeneous network is also "MIMO" referred to the use of multiple antennas at the used in wireless networks using different access transmitter and the receiver. In modern usage, "MIMO" technologies. For example, a wireless network which specifically refers to a practical technique for sending and provides a service through a wireless LAN and is able to receiving more than one data signal simultaneously over the maintain the service when switching to a cellular network is same radio channel by exploiting multipath propagation. called a wireless heterogeneous network.Reference to MIMO is fundamentally different from smart antenna a HetNet often indicates the use of multiple types of access techniques developed to enhance the performance of a single nodes in a wireless network. A Wide Area Network can data signal, such as beamforming and diversity. use macrocells, picocells, and/or femtocells in order to offer wireless coverage in an environment with a wide variety of wireless coverage zones, ranging from an open outdoor environment to office buildings, homes, and underground areas. Mobile experts define a HetNet as a network with complex interoperation between macrocell, small cell, and in some cases WiFi network elements used together to provide a mosaic of coverage, with handoff capability between network elements. A study from ARCchart estimates that Fig9. HetNets will help drive the mobile infrastructure market to account for nearly $57 Billion in spending globally by E. SON 2017.[4] Small Cell Forum defines the HetNet as ‘multi-x A Self-Organizing Network (SON) is an automation environment – multi-technology, multi-domain, multi- technology designed to make the planning, configuration, spectrum, multi-operator and multi-vendor. It must be able management, optimization and healing of mobile radio to automate the reconfiguration of its operation to deliver access networks simpler and faster. SON functionalityand assured service quality across the entire network, and behavior has been defined and specified in generally flexible enough to accommodate changing user needs, accepted mobile industry recommendations produced by business goals and subscriber behaviours. organizations such as 3GPP (3rd Generation Partnership Project)and the NGMN (Next Generation Mobile Networks). III. CONCLUSION SON has been codified within 3GPP Release 8 and Different adaptive techniques have been presented for subsequent specifications in a series of standards including different layers of a cellular wireless network based on the 36.902,[1] as well as public white papers outlining use cases LTE-Advanced standard. These techniques are workingon from the NGMN.[2] The first technology making use of SON top of each other and have to cover a large time scale in features will be Long Term Evolution (LTE), but the order to react appropriately to the different environmental technology has also been retro-fitted to older radio access changes, e.g., in the radio channeland in the user traffic. The technologies such as Universal Mobile Telecommunications interdependency between the different adaptive algorithms System (UMTS). The LTE specification inherently supports has to be taken intoconsideration carefully in order to SON features like Automatic Neighbor Relation (ANR) achieve an optimal capacity of the wireless network. International Journal of Scientific Engineering and Technology Research Volume.06, IssueNo.16, April-2017, Pages: 3002-3007

KAREEM MOHAMMED YASEEN AL.SAUDI, B. BHASKARA RAO The future 5G standard for cellular wireless networks, which will be based on larger bandwidth, much higher number of antennas and more sophisticated cell deployments,will require most likely even more sophisticated adaptive techniques. IV. REFERENCES [1] CE Shannon, W Weaver, TheMathematical Theory of Communication. (University of Illinois Press, Illinois, 1949). [2]S Sesia, I Toufik, M Baker, LTE —the UMTS Long Term Evolution. (John Wiley & Sons, Chichester, West Sussex, UK, 2011). [3] M Bossert, B Haetty, P Klund, in ITG-Fachbericht 124. Propagation aspects on railway environment in the GSM frequency range (InformationstechnischeGesellschaft, Frankfurt, Germany, 1993), pp. 319–330. [4] G Fettweis, M Lohning, D Petrovic, M Windisch, P Zillmann, W Rave, in IEEE 16th International Symposium on Personal, Indoor andMobile Radio Communications, 2005.PIMRC. Dirty, RF: a new paradigm (IEEE, Berlin, Germany, 2005). [5] PB Kenington, High-Linearity RF Amplifier Design. (Artech House, London, 2000). [6] E Aschbacher, Digital pre-distortion of microwave power amplifiers.PhDthesis.TechnischeUniversitätWien,Fakultätfür Elektrotechnik und Informationstechnik (2005). [7] M Schetzen, The VolterraandWiener Theories of Nonlinear Systems. (John Wiley, New York, 1980). [8] 3GPP TS 45.005: Technical specification group GSM/EDGE radio access network; radio transmission and reception (Release 12, March 2015). http://www.3gpp.org. [9] A Splett, H-J Dreßler, A Fuchs, R Hofmann, B Jelonnek, H Kling, E Koenig, A Schultheiß, in IEEE 2001 Custom Integrated Circuits Conference, CICC. Solutions for highly integrated future generation software radio basestation transceivers (IEEE, San Diego, USA, 2001). [10] TH Lee, The Design of CMOS Radio-Frequency Integrated Circuits(Cambridge University Press, Cambridge, 2004). [11]H Holma, AToskala, LTE for UMTS Evolution to LTE- Advanced. (John Wiley &Sons, Chichester, West Sussex, UK, 2011). [12] E Dahlman, S Parkvall, J Sköld, 4G LTE/LTE- Advanced forMobile Broadband. (Academic Press, Oxford, UK, 2011). [13] 3GPP TS 36.213: Technical specification group radio access network; Evolved Universal Terrestrial Radio Access (E-UTRA); physical layer procedures (Release 12, June 2015). http://www.3gpp.org. [14] 3GPP TR 36.897: Technical specification group radio access network; study on elevation beamforming/full- dimension (FD) MIMO for LTE (Release 13, July 2015). http://www.3gpp.org. [15]EU ProjectMETIS:Mobile and wireless communications enablers for the twenty-twenty information society. https://www.metis2020.com.

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