`Case 4:20-cv-07572-JSW Document 54-11 Filed 08/25/21 Page 1 of 14
`
`EXHIBIT K
`EXHIBIT K
`
`
`
`Case 4:20-cv-07572-JSW Document 54-11 Filed 08/25/21 Page 2 of 14
`
`See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/311795558
`
`An overview of massive mimo system in 5G
`
`Article · January 2016
`
`CITATIONS
`3
`
`3 authors, including:
`
`Koushik Barman
`Lovely Professional University
`
`18 PUBLICATIONS 14 CITATIONS
`
`SEE PROFILE
`
`READS
`3,984
`
`Some of the authors of this publication are also working on these related projects:
`
`I AM Coauthor of this paper. View project
`
`All content following this page was uploaded by Koushik Barman on 17 May 2020.
`
`The user has requested enhancement of the downloaded file.
`
`
`
`Case 4:20-cv-07572-JSW Document 54-11 Filed 08/25/21 Page 3 of 14
`
`I J C T A, 9(11) 2016, pp. 4957-4968
`© International Science Press
`
`AN OVERVIEW OF MASSIVE MIMO SYSTEM
`IN 5G
`Sk. Saddam Hussain*, Shaik Mohammed Yaseen2 and Koushik Barman3
`
`Abstract: 4G is proving good speeds up to 1Gbps. Then why do we need anything more. The problem is that it is
`not able to provide real time applications. 5G is the name given to the next generation of mobile data connectivity.
`It will definitely provide great speeds between 10Gbps to 100Gbps and it will have enough capacity. But the thing
`that separated 5G from 4G is latency; the latency provided by 4G is between 40ms to 60ms, whereas in 5G it will
`provide ultra latency between 1ms to 10ms. The standards for 5G will be set till 2020 and it will be applicable by
`2022/23. In this paper we have discussed about 5G and its advantages, a probable architecture for 5G and some
`challenges in 5G. The main technology that maybe used in 5G are massive MIMO, millimetre wave communica-
`tion, device to device communication, beam division multiple access etc. In this paper we have discussed about
`massive MIMO, channel estimate in massive MIMO, beam division multiple access technique to be used in mas-
`sive MIMO, antenna selection in massive MIMO, capacity and energy efficiency in massive MIMO. In future 5G
`is going to be a technology which will be invisible, I will be just there everywhere just like electricity. It is a very
`good area for research as standards and frequency band for 5G are yet to be standardised.
`Keywords: Massive MIMO, Beam Division Multiple Access (BDMA), channel estimate, energy efficiency, an-
`tenna selection.
`
`1. INTRODUCTION
`Mobile networking is a wireless technology than can provide voice and/or data networking, through a ra-
`dio transmission. Mobile phone is one of the most famous applications of mobile networking. In past cir-
`cuit switching was used to transmit voice over a network, then we moved on to use both circuit-switching
`and packet-switching for voice and data, now presently we are using packet switching only, this is how
`spectrum has expanded from 1G to 4G [1]. Today and in upcoming future wireless networks need to be
`improved for meeting the demand for increased data rate, improved capacity, reduced latency and good
`quality of service. We are in the 4th generation of wireless communication, so now research is going on
`for developing new standards for the next generation beyond 4G i.e. 5G. With increasing demands of
`subscribers definitely 4G will be replaced by 5G with the help of some advanced technologies like mas-
`sive MIMO, device-to-device communication, millimetre wave communication, Beam division multiple
`access in massive MIMO etc. The technologies used in 4G like High-Speed Packet Access (HSPA) and
`Long Term Evolution (LTE) will be used as a part of future advancement. For this advancement we may
`use different methods, It may happen that we may use different spectrum access technique, increased fre-
`quency range, deploying large number of antennas etc. [1]
`This whole thing started in 1970s, till now the mobile wireless communication has come a long way
`from analog communication to today’s modern digital mobile communication providing the subscribers
`with improved data rate of megabits per second over wide area and few hundreds of megabits per second
`in a local area. We are going on well toward next stepping stone in future i.e. 5G.It is predicted that 5G will
`be in operation by 2020, hence immense research in going on in this field. The world is imagining a future
`where there is no restriction to the access and sharing of information from anywhere by anyone.
`
`* Department of Electronics and Communications Lovely Professional University, Punjab, India
`
`Email: shaik.hussain.saddam@gmail.com, smdyaseen.619@gmail.com2, koushik.15737@lpu.co.in3
`
`
`
`Case 4:20-cv-07572-JSW Document 54-11 Filed 08/25/21 Page 4 of 14
`
`4958
`
`2. WHAT IS 5G AND WHY DO WE NEED IT?
`5G is the name given to the next generation of wireless connectivity. It will provide great speeds and a
`good capacity. We are in the 4G now, having speeds of up to 150Mbps in areas of double LTE connections,
`300Mbps for LTE-A connections and Pocket-lint (the largest independent gadget news and reviews site in
`the UK) has predicted that the speeds will improve up to 1Gbps in 4G. This speed is more than enough,
`then why on earth we need something more, why we need 5G? it is sure that 5G will provide unbelievable
`speeds between 10Gbps and 100Gbps. But latency is the thing that is very important, in 4G it is between
`40ms and 60ms. This is a very low latency but not able to provide real-time applications like in a multi-
`player game we want our server to respond very quickly when a button is pressed. When it comes to 5G,
`they have promised a ultra-low latency between 1ms to 10ms. Then in future we can actually watch a
`cricket or football or any conference actually live without any delay. 5G is a technology that will appear to
`be invisible; it will be just there like electricity. Management of the available bandwidth is very important
`for improving the capacity, one idea is that as not all devices need the same bandwidth, we may provide
`bandwidth according to the needs and hence improve the capacity.
`Some of the key technologies to be used in 5G are massive MIMO, device-to-device communication,
`millimetre wave communication and some multiple access techniques like beam division multiple access
`(BDMA). Everything around us will be connected to network, the sensors network, the ad-hoc networks,
`our accounts, laptops, pc etc. Analysis tells that by the year 2020, every person in UK will have 27 internet
`connected devices and 50 billion connected devices worldwide. This is definitely going to happen in fu-
`ture and it is given the name internet of things and beyond this it is internet of everything [1]. The devices
`connected may be mobile phones, tablets, watches, smart cloths etc. some may require significant amount
`of data to be transferred back and forth, the others may just need small packets of data, hence depending
`on these bandwidth can be allotted for the improvement of overall capacity of the system.
`
`Figure 1. Things that will happen in future [1]
`
`3. EVOLUTION OF 5G
`First Generation (1G)-1981: The 1G was based on analog communication. They had poor traffic density
`i.e. only one call per channel, poor voice quality and they were insecure without any encryption.
`Second Generation (2G)-1991: The 2G was based on digital communication with different standards.
`Among these standards the most famous were GSM (Global System for Mobile), CDMAOne (Code
`
`Sk. Saddam Hussain, Shaik Mohammed Yaseen and Koushik Barman
`
`
`
`Case 4:20-cv-07572-JSW Document 54-11 Filed 08/25/21 Page 5 of 14
`
`4959
`
`Division Multiple Access One), IS-136, and PDC (Pacific Digital Cellular). GSM was the most famous of
`all; it’s being used even now. GSM used a frequency band between 900MHz and 1800 MHz, they devel-
`oped a technology called SIM for authenticate a subscriber for identification and billing purposes, and for
`encryption of data.
`Second to Third Generation Bridge (2.5G)-2000: In 2.5G the data was added along with voice. In be-
`tween 2G and 3G a famous service called GPRS (general Packet Radio Service) was introduced, which
`provided services like send and receive e-mail and picture messages. They provide operation speeds up to
`115kbps, which was increased up to 384Kbps by using EDGE (Enhanced Data rates for Global Evolution).
`Third Generation (3G)-2003: 3G used a higher frequency bands and CDMA for data transmission with
`speeds up to 2Mbps and supported multimedia services like MMS. The famous standard in 3G was WCD-
`MA (Wideband Code Division Multiple Access) which achieved speeds between 384Kbps and 2048Kbps.
`They continued using SIM authentication for billing systems and for encryption of data.
`Fourth Generation (4G)-2007: 4G can provide speeds up to 150Mbps in areas of double LTE connec-
`tions, 300Mbps for LTE-A connections and Pocket-lint (the largest independent gadget news and reviews
`site in the UK) has predicted that the speeds will improve up to 1Gbps in 4G., ad hoc networking model is
`used as a base as there is no need for a fixed infrastructure. The famous standards used are LTE-A (Long
`Term Evolution- Advance) by 3GPP and Wimax by IEEE. They provide latency between 40ms and 60ms.
`
`Table 1
`Difference between 1G, 2G, 3G, 4G, 5G [11]
`
`Technologies
`/ Features
`Evolution
`Deployment
`Data Rate
`
`Famous
`Standards
`
`Technology
`behind
`
`1G
`
`1970
`1984
`2 kbps
`
`AMPS
`
`Analog cellular
`technology
`
`2G/2.5G
`
`1980
`1999
`14.4-64 kbps
`
`3G
`
`1990
`2002
`2 Mbps
`
`2G: GSM,C]DMA
`2.5G: GPRS,
`EDGE, 1xRTT
`Digital cellular
`technology
`
`WCDMA,
`CDMA-2000
`
`Broad bandwidth
`CDMA, IP tech-
`nology
`
`Service
`
`Voice
`
`2G: Digital Voice,
`SMS
`2.5G: Voice+Data
`
`Integrated high
`quality audio,
`video and data
`
`Multiplexing
`Type of Switching
`
`FDMA
`Circuit
`
`TDMA,CDMA
`2G: Circuit
`2.5G: Circuit and
`packet
`Horizontal
`
`CDMA
`Packet
`
`Horizontal
`
`Horizontal
`
`Handoff
`
`Core
`Network
`
`PSTN
`
`PSTN
`
`Packet network
`
`4G
`
`5G
`
`2000
`2010
`200 Mbps to
`1 Gbps for low
`mobility
`LTA, WiMAX
`
`2010
`2015
`10 Gbps to 100
`Gbps
`
`Not yet defined
`
`Undefined IP and
`seamless combina-
`tion of broadband.
`LAN/WAN/PAN/
`WLAN
`Dynamic informa-
`tion access, wear-
`able devices
`
`CDMA
`Packet
`
`Undefined IP and
`seamless combi-
`nation of broad-
`band. LAN/WAN/
`PAN/WLAN
`Dynamic infor-
`mation access,
`wearable devices
`with AI capabili-
`ties
`CDMA
`Packet
`
`Horizontal and
`Vertical
`Internet
`
`Horizontal and
`Vertical
`Internet
`
`An Overview of Massive MIMO System in 5G
`
`
`
`Case 4:20-cv-07572-JSW Document 54-11 Filed 08/25/21 Page 6 of 14
`
`4960
`
`4. CAPABILITIES OF 5G
`To enhance such a wide range of technologies, 5G obviously have to concentrate on some parameters
`which lead to the requirements and capabilities for the network to differ from other generations. Some of
`them are listed below Energy consumption and low cost: It has been always the great challenge for mobile
`communication to provide the services and features for low energy and low cost. However, to avail all
`the services for wireless sensor network wherein we have millions of sensors, subsystems and actuators
`connected, work has been done in many energy efficient protocols and algorithms and thus in 5G they are
`yet to be implemented.
`Performance of Network: As the device energy consumption was up to manageable with high energy
`efficient algorithms there exists a problem of ‘High Network Energy Performance’ which is again a major
`emerging task for operator. Recent technologies are relaying on large solar panels for power supply, thus
`the energy problems in remote areas are widely handled by these solar panels.so energy efficient of large
`network is always a challenge for an operator to fulfill all its services [12].
`Lower Latency: Latency is mainly defined as the delay response of the device.as the name suggest, it
`is the important parameter to achieve the promising services as higher data rates and high response time.
`However, to achieve the low latency it’s always been a challenge for developers. As the 5G deals with
`higher data rates there exists a main issue of how to lower the latency. To support such lower latency ap-
`plications should be given end-end latency of less than 1ms.
`It is somehow achieved for fast growing applications as
` ● Traffic safety
` ● Control of infrastructure
` ● Industrial processes
`High availability & Reliability: Another important aspect after lower latency is high availability and high
`reliability. High reliability includes the system services as well as hardware architecture where in high
`availability includes the channel bandwidth, providing a higher bandwidth is again a difficult task. Con-
`nectivity with the required characteristics is essentially available with less deviation [11].
`Very large System Capacity: Traffic services for cellular communication systems are dramatically
`increasing. To enhance with such traffic in simple way, 5th Generation networks must be capable of trans-
`ferring data at much lower cost on bit rate compared to present networking system. However, in order to
`operate with the same or even lower the energy consumption, 5G has to work on lower energy consump-
`tion per bit delivered. As compared with present scenario 5G system must be capable of supporting huge
`number of devices. Thus it’s again a challenge for 5G operation in millions of wireless sensor networks
`which include sensors, actuators, sink, and sources etc. This challenge is mainly in terms of efficient use
`of protocols [13].
`
`5. 5G ARCHITECTURE
`In general a research have shown that a mobile subscriber stays inside for approximately 80 percentage
`of time and outside for approximately 20 percentage of time. From this scenario for a subscriber inside
`will receive a call when signal penetration through the walls, then that signal will undergo many losses
`and hence efficiency will be less, bit rate will be low and low energy efficiency. This is happening because
`there is only one base station at the middle of the cell site that handles all these. When it comes to 5G ar-
`chitecture it has different models for outside and inside. By doing so some of the penetration losses can be
`reduced. This will be implemented using massive MIMO technology by deploying hundreds of antennas.
`
`Sk. Saddam Hussain, Shaik Mohammed Yaseen and Koushik Barman
`
`
`
`Case 4:20-cv-07572-JSW Document 54-11 Filed 08/25/21 Page 7 of 14
`
`4961
`
`Normally in MIMO system we utilized two or four antennas, by using massive MIMO we are increasing
`number of transmitter and receiver antennas approximately between ten to hundred, by doing so we are
`increasing the capacity gain [1]. In massive MIMO network two things are setup for establishing a reliable
`network. First, a base station will be installed in a cell site with multiple antennas on it or in the area of
`cell; these are connected with the base station using optical fibre cables. When a subscriber is outside he
`is connected to the base station directly or connected via multiple hops from the antennas creating virtual
`massive MIMO network. Secondly an antenna array will be installed in every building; these antennas
`will be in line of sight with the base station. The communication inside is done using technologies like
`Wi-Fi, visible light communication, millimetre wave communication etc [1].
`
`Figure 2. General 5G cellular network architecture [7]
`
`6. MASSIVE MIMO
`MIMO stands for Multiple Input and Multiple Output that means we use multiple antennas at the trans-
`mitter and receiver, this is called spatial diversity. Up until the 1990s, spatial diversity was often limited
`to systems that switched between two antennas. If we use multiple antennas at the transmitter we call it
`as transmitter diversity and at receiver we call it as receiver diversity. By doing so we are increasing the
`channel capacity and reliability of the wireless network. During the start of this technology point-to-point
`MIMO were used were both transmitter and receiver have multiple antennas, soon it was over taken by
`multi-user MIMO where there were multiple antennas at the base station which communicated with the
`single antenna receiver. Due to this cost of the whole system was reduced because now costly antennas
`were only needed at the base stations, cheap antennas can be used at the single antenna end [3].
`One advantage of this technology is that we can increase the capacity and reliability, the other is that
`we can reduce the error rate. If we can transmit multiple versions of our message through different chan-
`nels the probability all the signals will be affected same will be less. At the receiver these multiple copies
`are received and processed to get our original message. Hence Diversity also helps to stabilise a com-
`munication link, improves its performance, and reduces error rate. Due to all these advantages MIMO
`technology is deployed as a part of communication standards such as 802.11 (WiFi), 802.16 (WiMAX),
`and LTE [3].
`
`An Overview of Massive MIMO System in 5G
`
`
`
`Case 4:20-cv-07572-JSW Document 54-11 Filed 08/25/21 Page 8 of 14
`
`4962
`
`The communication in MIMO take place in two formats called spatial diversity and spatial multiplex-
`ing. In spatial diversity, the same data is transmitted through different paths; the data is received at the
`multiple antennas and processed. By spatial multiplexing we can improve the reliability of the link. The
`other technique is spatial multiplexing, where the data is divided into small parts and different part is
`transmitted through different path, by doing so we are increasing the speed, but reliability is less.
`A MIMO system consists of a number of transmitter and receiver antennas and a fading channel
`through which the data will be sent. Let us consider we have M, number of transmitter antennas and N,
`number of receiver antenna i.e. we form a matrix for transmitter and receiver antennas having t number of
`rows in transition matrix similarly r number of rows in receiver matrix.
`The basic equation for MIMO system is given by Y= H.X + W
`Where, Y = N x 1 Receiver matrix
`
`H = N x M Channel matrix
`
` X = M x 1 Transition matrix
`
`W = Noise
`
`Figure 3: MIMO System
`
`Figure 4: Matrix Representation of MIMO
`In future to achieve more gain and to reduce the signal processing, massive MIMO or large-scale
`antenna system (LSAS) have been proposed. The general MIMO system consists of not more than 10 an-
`tennas, whereas in massive MIMO there could be 100 or more antennas [4], [5]. But not all the antennas
`will work at the same time; a limited number of antennas will be operating at a time because of the limita-
`tions to acquire channel state information. Massive MIMO technology can be made possible by combin-
`ing the conventional TDMA, FDMA and OFDM multiplexing technology. Future prediction is that the
`Massive MIMO technology will use very low power in the order of milliwatts. The major challenges are
`
`Sk. Saddam Hussain, Shaik Mohammed Yaseen and Koushik Barman
`
`
`
`Case 4:20-cv-07572-JSW Document 54-11 Filed 08/25/21 Page 9 of 14
`
`4963
`
`multiuser multiplexing gains, error in channel state information and interference. The power consumption
`at the base stations is a growing concern [6]. We assume that the number of antennas at the base station is
`more than the number of users; hence we have more degree of freedom, so that we can perform effective
`transmition and avoid interference [7]. Another advantage of massive MIMO system is energy efficiency,
`prediction is that a single-antenna user in a massive MIMO system can reduce down its transmit power
`proportional to the number of antennas at the base station with perfect channel state information (CSI) or
`to the square root of the number of base station antennas with imperfect CSI, to get the same performance
`as a corresponding single-input single-output (SISO) system. So there will be higher energy efficiency and
`this is very important for wireless networks where excessive energy consumption is a growing concern
`[8], [9], [10]. If adequate power is available at the base station then massive MIMO system can increase
`the range of operation compared to SISO system.
`
` Figure 5: Illustration of Massive MU-MIMO systems
`Massive MIMO system can be built with inexpensive and low power gadgets. The high power ampli-
`fiers may be replaced by low cost amplifier with output power in the range of milli-watt. Several expensive
`and bulky equipment like coaxial cable used for connecting the BS with other BS and mobile switching
`centre, can be eliminated. The massive MIMO system works on the principal that the noise, fading, any
`imperfections are averaged out when signals from several antennas are combined. Massive MIMO system
`has high degree of freedom, because they have more than 100 antennas but not all are working at the same
`time. Massive MIMO system will have very low latency. Latency in a system is due to fading, when the
`signal travel through multi path and reach at the receiver and add destructively. As in massive MIMO sys-
`tem there are going to be many antennas and high degrees of freedom this latency can be reduced. There
`are some limitations of massive MIMO that might be channel reciprocity and pilot contamination. These
`might happen due to adjacent cell interference, which need to be taken care.
`
`7. BEAM DIVISION MULTIPLE ACCESS
`The aim of mobile communication is to provide flexible and improved connection to everyone at low
`cost. As in future more and more subscribers are going to join to the network increasing the capacity, so
`future requirement is to provide a good capacity and quality of service. It’s like there should not be any
`drop in speed wherever the subscriber goes and any number of them are connected at the same time to the
`network. The frequency band for 5G is yet to be decided, an prediction is millimetre band is going to be
`used 30 to 300 GHz may be used. The main obstacle in mobile communication is limited frequency and
`time, so to overcome this we have used many multiple access techniques like Frequency Division Multiple
`Access (FDMA), Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA),
`Orthogonal Frequency Division Multiple Access (OFDMA) techniques, etc. [2]
`
`An Overview of Massive MIMO System in 5G
`
`
`
`Case 4:20-cv-07572-JSW Document 54-11 Filed 08/25/21 Page 10 of 14
`
`4964
`
`The time and frequency are divided among many users but it is limited as frequency and time are
`limited. In future there will be more mobile station and will be increasing, the previous technique are
`not enough to manage. We need a new technique for 5G, so the Korean research and development came
`up with the idea of new multiple access technique called as Beam Division Multiple Access (BDMA).
`An orthogonal beam is provided by the base station to each mobile station. To allow multiple accesses in
`BDMA the beam is divided according to the location and improving the capacity. The base station and
`mobile station are in line of sight communication when they know each other’s position, and hence avoid-
`ing the interference. BDMA is a new space division multiple access technique which uses phased antenna
`array, use beam forming technique to produce directive beam and uses multiple beam forming patterns for
`multiple access [2].
`
`Figure 6: Beam Division Multiple Access [2]
`When mobile stations are present at different positions or angles, each one of them are provided with a
`beam separately. If the mobile stations are in same location then they use a single beam, by using the avail-
`able frequency/time for multiple accesses. The base station can change the direction, number of beams and
`width of the beam according to the position and speed of the mobile station. The available beam can be
`divided into three-dimensions and hence improving the capacity. The steps followed for set of connection
`are as follows:
` ● Initially the base station and mobile station are unknown to each, the mobile station determine its loca-
`tion and speed and transmit this information omni-directionally to the base station.
` ● The base station determines the direction and width of the beam depending on the information re-
`ceived from the mobile station. This beam is called downlink beam as it is from base station to the
`mobile station.
` ● Now the base station transmits this downlink beam to the mobile station.
` ● The mobile station on receiving this downlink beam track the direction of this beam for sending an
`uplink beam in the set direction.
` ● Base station on receiving this uplink beam establishes a communication. The periodic updating of
`beam must be done for communication to carry out smoothly.
`
`Sk. Saddam Hussain, Shaik Mohammed Yaseen and Koushik Barman
`
`
`
`Case 4:20-cv-07572-JSW Document 54-11 Filed 08/25/21 Page 11 of 14
`
`4965
`
`8. CHANNEL ESTIMATE IN MASSIVE MIMO
`In massive MIMO the communication is happening through spatial multiplexing, which require channel
`estimate in both uplink and downlink direction. In regular MIMO channel state information (CSI) is re-
`quired at the base station (BS) for precoding in downlink and for detection in uplink. Channel estimate
`in MIMO is proportional to number of transmit antenna and is nothing to do with number of receiver
`antennas. In frequency division duplex (FDD), as uplink and downlink use different frequency there is
`a need to find the CSI in uplink and downlink separately. For uplink channel estimate a pilot sequence
`is send by all users to the BS, and this is independent of the number of antennas at the BS. However
`for downlink channel estimate there are two stages, first the BS send a pilot symbol to all users, next
`the users send the feedback with estimate CSI to the BS. The time required to transmit the downlink
`pilot symbol proportional to number of antennas at the BS. More the number of antennas at the BS the
`channel estimate become impractical. This problem can be overcome by using time division duplex
`(TDD), where channel reciprocity is used as the same channel is used for uplink and downlink. So just
`the channel estimate is one direction is enough. A TDD protocol is proposed in [14], shown below. This
`protocol says that, first all user synchronously send user uplink data, next user send a uplink pilot se-
`quence which is used by BS to estimate the CSI for that user in that cell. BS uses this CSI to know the
`uplink data and form a beamforming signal for downlink transmission. But the pilot sequence from the
`neighbouring cell and the pilot sequence within the cell are not orthogonal, so there is problem of pilot
`contamination [4]. Linear min-mean square error (MMSE) method is used which can provide optimal
`results with less complexity. In addition to linear MMSE, a compressive sensing-based channel estima-
`tion approach is proposed in [15], a time-frequency training sequence design is developed in [16] for
`improving the spectral efficiency.
`
`Figure 7: MIMO TDD protocol [14]
`
`9. ANTENNA SELECTION
`Due to the increasing demands of the subscribers there is a need for new technology which can handle this
`situation, such that it should improve the channel efficiency, data rate and provide required quality of ser-
`vice. MIMO is one of the solutions for this situation, it is able to provide the required performance using
`multiple transmitter and receiver antennas. By increasing the number of antennas we are improving our
`performance but it is costly in terms of size and hardware at the base station and the computation power at
`the base station. So we require a efficient method to reduce this cost, one way of doing this by using a fast
`antenna selection algorithm. Antenna selection algorithm can be applied at transmitter, receiver or both.
`For channel maximization we require a proper selection of transmitter antennas, there are some algorithms
`where selection is done based on power, channel correlation matrix and channel state information [19].
`Some of the antenna selection algorithms have been discussed in [21] [22] and [23].
`
`10. CAPACITY AND ENERGY EFFICENCY IN MASSIVE MIMO
`Massive MIMO system will improve the capacity 10 times and the energy efficiency is improved 100
`times that of a conventional MIMO system. The improvement in capacity is due to the use of spatial mul-
`tiplexing. The beam division multiple access (BDMA) technique to be used in massive MIMO will allot
`
`An Overview of Massive MIMO System in 5G
`
`
`
`Case 4:20-cv-07572-JSW Document 54-11 Filed 08/25/21 Page 12 of 14
`
`4966
`
`a beam for each used which are orthogonal to each other. The mobile users in a same location will use
`the same beam using multiple access techniques like TDMA/FDMA, hence improving the capacity. The
`increase in the energy efficiency is also due to focusing of the beam in particular target location [17].
`Figure 9 shows the concept of coherent superposition of wavefronts. The BS makes sure that the
`waveforms generated by all the antennas add constructively at the target and destructively anywhere else.
`Figure 8 from [8], shows the trade-off between the energy efficiency in terms of the total number of bits
`(sum-rate) transmitted per Joule per terminal receiving service of energy spent, and spectral efficiency in
`terms of total number of bits (sum-rate) transmitted per unit of radio spectrum consumed. This figure11
`shows the spectral efficiency for uplink transmission from mobile users to the BS. The graph shows that
`uplink spectral efficiency is improved 10 times and the radiated power efficiency is improved by 100 times
`for massive MIMO [8].
`
`Figure 8: Spectral-Efficiency (bits/s/Hz) Vs Relative Energy-Efficiency (bits/J)/(bits/J)
`
`Figure 9: Relative field strength around a target terminal in a scattering environment of size 800λ×800λ, when the
`base station is placed 1600λ to the left. Average field strengths are calculated over 10000 random placements of 400
`scatterers, when two different linear precoders are used: a) MRT precoders and b) ZF precoders.
`
`11. CONCLUSION
`5G will provide great speed and enough capacity; it’s like wherever the mobile station moves there will
`be no drop in speed even though any numbers of mobile users are connected to the network at the same
`
`Sk. Saddam Hussain, Shaik Mohammed Yaseen and Koushik Barman
`
`
`
`Case 4:20-cv-07572-JSW Document 54-11 Filed 08/25/21 Page 13 of 14
`
`4967
`
`time. Massive MIMO is the future technology which will help to attain the requirements of 5G. TDMA,
`FDMA and other multiple access techniques may not be applicable to provide good capacity efficiency as
`the frequency and time are limited. So we need a new technique called Beam Division Multiple Access to
`be used in Massive MIMO to improve the capacity. The channel estimation in massive MIMO is a great
`challenge so as to provide low bit error rate. By using massive MIMO the system capacity is increased
`10times and energy efficiency is improved by 100times. As the cost of infrastructure for 5G will be ex-
`pensive, so one way to reduce the cost is by reducing the processing at the transmitter and receiver which
`can be achieved using a appropriate antenna selection algorithm. If all things fall in place 5G may be ap-
`plicable by 2022/23. So there is going to be a Bright future ahead.
`
`Refrence
`1. Akhil gupta and Rakesh kumar jha, “A survey of 5g network: architecture and emerging technologies” IEEE Access, July
`2015.
`2. Chen Sun, Xiqi Gao, Shi Jin, Michail Matthaiou, Zhi Ding, Chengshan Xiao,” Beam Division Multiple Access Transmis-
`sion for Massive MIMO Communications”, IEEE, 2015.
`3. Lu Lu, Geoffrey Ye Li, A. Lee Swindlehurst, Alexei Ashikhmin, and Rui Zhang, “An Overview of Massive MIMO: Ben-
`efits and Challenges”, IEEE journal of selected topics in signal processing, Vol.8, No.5, October 2014.
`4. T. L. Marzetta, “Multi-cellular wireless with base stations employing unlimited numbers of antennas,” in Proc. UCSD Inf.
`Theory Applicat. Workshop, Feb. 2010.
`5. T. L.Marzetta, “Noncooperative cellular wireless with unlimited numbers of base station antennas,” IEEE Trans. Wireless
`Commun., vol. 9, no. 11, pp. 3590–3600, Nov. 2010.
`6. Vahid Tarokh, Hamid Jafarkhani, A. Robert Calderbank, “Space–Time Block Coding for Wireless Communications: Per-
`formance Results”, IEEE Journal, vol.17, 1999.
`7. E. G. Larsson, “Very large MIMO systems: Opportunities and challenges,” 2012 [Online]. Available: http://www.kth.se/
`polopoly_fs/1.303070!/Menu/general/column-content/attachment/Large_MIMO.pdf
`8. H. Q.Ngo,E.G.Larsson, and T. L.Marzetta, “Energy and spectral efficiency of v