Nokia_1 LTE Overview Nokia

LTE: Long Term Evolution SAE: System Architecture Evolution

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WLAN: Wireless Local Area Network GSM: Global System for Mobile UMTS: Universal Mobile Telecommunications System

Worldwide demand for mobile data services is primed for explosive growth, fueled by rapidly improving quality and availability. Across the spectrum, consumers are demanding more from mobile. They want expanded services, richer multimedia experiences, easier access and greater personalization. The key applications for the next generation of mobile users include person-toperson communications, content delivery, social networking, business services and mobile commerce. To deliver these applications with the quality of service that customers expect, mobile networks must achieve higher performance. The prerequisites are high-speed, broadband-like access via mobile devices, delivered anywhere and at any time.

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Latency is a measure of time delay experienced in a system, the precise definition of which depends on the system and the time being measured. In communications, the lower limit of latency is determined by the medium being used for communications. In reliable two-way communication systems, latency limits the maximum rate that information can be transmitted, as there is often a limit on the amount of information that is "in-flight" at any one moment. In the field of human-machine interaction, perceptible latency has a strong effect on user satisfaction and usability GPRS

-> Latency -> 700ms

EDGE

-> Latency -> 300ms

WCDMA -> Latency -> 200ms HSDPA -> Latency -> 130ms HSUPA -> Latency -> 100ms

802.11n The newest IEEE standard in the Wi-Fi category is 802.11n. It was designed to

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improve on 802.11g in the amount of bandwidth supported by utilizing multiple wireless signals and antennas (called MIMO technology) instead of one.When this standard is finalized, 802.11n connections should support data rates of over 100 Mbps. 802.11n also offers somewhat better range over earlier Wi-Fi standards due to its increased signal intensity. 802.11n equipment will be backward compatible with 802.11g gear. Pros of 802.11n - fastest maximum speed and best signal range; more resistant to signal interference from outside sources Cons of 802.11n - standard is not yet finalized; costs more than 802.11g; the use of multiple signals may greatly interfere with nearby 802.11b/g based networks. IEEE 802.16 is a series of Wireless Broadband standards written by the Institute of Electrical and Electronics Engineers (IEEE). Although the 802.16 family of standards is officially called WirelessMAN in IEEE, it has been commercialized under the name "WiMAX" (from "Worldwide Interoperability for Microwave Access")

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WiMAX, (Worldwide Interoperability for Microwave Access), is a data transmission standard that uses radio waves at frequencies from 2.3 to 3.5 GHz and can be covered up to 60 km The 802.16d standard for fixed terminals, and 802.16e for moving stations The WIMAX best known versions are the 802.16d and 802.16e, the 802,16d adds mobility to be used in portable devices Style Smart Phones and tablets and finally 802.16 m, like Wi-Fi 802.11n significantly increases transmission capacity increasing the width data channel and using technologies like MIMO, beamforming, etc.. although it has not been adopted yet. Standars:  802.16d -> About 70 Mbps -> Channels up to 10 MHz  802.16e -> About 70 Mbps -> Channels up to 10 MHz

 802.16m -> Resting 1 Gbps and 100Mbps on move -> Channels up to 20 MHz

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3G services are expanding the market for mobile networks. Operators must evolve by providing multimedia services at higher data rates and lower costs. The solution is to deliver all IP-based content services over the air interface. Market factors are mandating a near-term, industry-wide evolution from WCDMA/HSPA to HSPA+ or direct to LTE. Companies have responded by creating UTRAN products, solutions andmigration scenarios that enable operators to capitalize on emerging and long-term market demands

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Transparent Flat Rate: It charges a fixed amount, regardless of the number of hours you use the connection. ARPU: Average Revenue Per Use -> It is calculated by dividing the total income

earned in the period between the total assets of the business users

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LTE SAE System Overview

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Technical advantages to 3G: High data throughput, PS transmission, lower latency, wider coverage and downward compatibility

Confidential Information of Huawei. No Spreading Without Permission

Backwards Compatibility: In programming languages, backward compatibility

refers to the ability of a compiler for version N of the language to accept programs or data that worked under version N - 1. By this definition, if previous versions (N - 1, N - 2, etc.) were also backward compatible, which is often the case, then, by induction, version N will also accept input that worked under any prior version after, and including, the latest one that was not backward compatible. However, in practice, features are often deprecated and support is dropped in a later release, which is yet thought of as backward compatible. In other contexts, a product or a technology is said to be backward compatible when it is able to fully take the place of an older product, by inter-operating with products that were designed for the older product. Turbo Code :In information theory, turbo codes (originally in French Turbocodes) are a class of high-performance forward error correction (FEC) codes developed in 1993, which were the first practical codes to closely approach the channel capacity, a theoretical maximum for the code rate at which reliable communication is still possible given a specific noise level. Turbo codes are finding use in 3G mobile communications and (deep

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space) satellite communications as well as other applications where designers seek to achieve reliable information transfer over bandwidth- or latencyconstrained communication links in the presence of data-corrupting noise FEC: Forward Error Correction -> The forward error correction is a type of error correction mechanism that allows correction in the receiver without retransmission of the original information WLAN IW: Wireless Local Area Network InterWorking: Interacciones de las redes WLAN con otras redes WCDMA: Wideband Code Division Multiple Access EPC: Envolved Packet Core IMS: IP Multimedia Subsystem

Multimedia Broadcast Multicast Services (MBMS) is a point-tomultipoint interface specification for existing and upcoming 3GPP cellular networks, which is designed to provide efficient delivery of broadcast and multicast services, both within a cell as well as within the core network • In telecommunication and information theory, broadcasting refers to a method of transferring a message to all recipients simultaneously.

• In computer networking, multicast is the delivery of a message or information to a group of destination computers simultaneously in a single transmission from the source.

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MIMO: The Multiple Input Multiple Output antenna solution is a powerful technique for baseband signal processing. MIMO uses on array of transmitand-receive antennas to obtain an improved link budget in urban areas where there are a number of signal reflections. The 2x2 MIMO solution uses only two transmit and two receive antennas. Operator benefits include better signal propagation in urban areas and higher throughput capability. In telecommunications the round-trip delay time (RTD) or round-trip time (RTT) is the length of time it takes for a signal to be sent plus the length of time it takes for an acknowledgment of that signal to be received. This time delay therefore consists of the propagation times between the two points of a signal.

Reassigning government-regulated electromagnetic spectrum for services with higher value. The users of the existing spectrum are forced out, although they may be compensated in some manner. The frequency bands are assigned to communications services that yield greater economic or social benefit. Scalability of bandwidth Urban areas: Most likely LTE will be deployed. Stepwise deployment in UMTS 2.1 bands will be possible at a later stage. Rural areas: Option 1: deploy UMTS in 900 MHz band. Advantage: rollout can start now Disadvantage: a block of 5 MHz need to be taken out of the GSM band. Not a lot of operators can affort to take out this much of spectrum due to heavy usage in this band Option 2: Introduce LTE in 900 MHz band Advantage:

reuse of GSM 900 Sites.

granularity (1.4 / 3 / 5 /…MHz).

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ITU: International Telecommunication Union

WiMAX (Worldwide Interoperability for Microwave Access) is a wireless communications standard designed to provide 30 to 40 megabitper-second data rates,[1] with the 2011 update providing up to 1 Gbit/s for fixed stations

Cost per Mbyte decreases with intoduction of new technologies. From HSPA > LTE cost per Mbyte will reduce with more than 70% Why?

-Increased spectral efficiency > bits per Hz per cell for LTE (2X2 Mimo) ~ 1.7 -Flat architecture. -Reuse of spectrum > refarming of existing 900 MHz band in rural areas possible. For urban larger bandwidth expected in 2.6 GHz.

The targets for the evolution of the radio-interface and radio-access network architecture should be: - Significantly increased peak data rate e.g. 100 Mbps (downlink) and 50 Mbps (uplink) - Increase "cell edge bitrate" whilst maintaining same site locations as deployed today

- Significantly improved spectrum efficiency ( e.g. 2-4 x Release 6) - Possibility for a Radio-access network latency (user-plane UE – RNC (or corresponding node above Node B) UE) below 10 ms - Significantly reduced C-plane latency (e.g. including the possibility to exchange user-plane data starting from camped-state with a transition time of less than 100 ms (excluding downlink paging delay)) - Scaleable bandwidth - 5, 10, 20 and possibly 15 MHz - [1.25,] [1.6,] 2.5 MHz: to allow flexibility in narrow spectral allocations where

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the system may be deployed - Support for inter-working with existing 3G systems and non-3GPP specified systems ETSI 3GPP TR 25.913 version 8.0.0 Release 8 7 ETSI TR 125 913 V8.0.0 (2009-01) - Further enhanced MBMS

- Reduced CAPEX and OPEX including backhaul - Cost effective migration from Release 6 UTRA radio interface and architecture - Reasonable system and terminal complexity, cost, and power consumption. - Support of further enhanced IMS and core network - Backwards compatibility is highly desirable, but the trade off versus performance and/or capability enhancements should be carefully considered.

- Efficient support of the various types of services, especially from the PS domain (e.g. Voice over IP, Presence) - System should be optimized for low mobile speed but also support high mobile speed - Operation in paired and unpaired spectrum should not be precluded - Possibility for simplified co-existence between operators in adjacent bands as well as cross-border co-existence

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AMPS: Advanced Mobile Phone System

Wireless communication is the transfer of information between two or more points that are not connected by an electrical conductor.

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FDD: Frequency-division duplexing (FDD) means that

the transmitter and receiver operate at different carrier frequencies. The term is frequently used in ham radio operation, where an operator is attempting to contact a repeater station. The station must be able to send and receive a transmission at the same time, and does so by slightly altering the frequency at which it sends and receives. This mode of operation is referred to as duplex mode or offset mode. Time-division duplexing (TDD) is the application of time-division multiplexing to separate outward and return signals. It emulates full duplex communication over a half duplex communication link. Time-division duplexing has a strong advantage in the case where there is asymmetry of the uplink and downlink data rates. As the amount of uplink data increases, more communication capacity can be dynamically allocated, and as the traffic load becomes lighter, capacity can be taken away. The same applies in the downlink direction.

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TTI: Transmission Time Interval In information theory, the Shannon–Hartley theorem tells the maximum rate at which information can be transmitted over a communications channel of a specified bandwidth in the presence of noise. It is an application of the noisy channel coding theorem to the archetypal case of a continuous-time analog communications channel subject to Gaussian noise Peak Data Rate E-UTRA should support significantly increased instantaneous peak data rates. The supported peak data rate should scale according to size of the spectrum allocation.

Note that the peak data rates may depend on the numbers of transmit and receive antennas at the UE. The targets for downlink (DL) and uplink (UL) peak data rates are specified in terms of a reference UE configuration comprising: a) Downlink capability – 2 receive antennas at UE

For this baseline configuration, the system should support an instantaneous downlink peak data rate of 100Mb/s within a 20 MHz downlink spectrum allocation (5 bps/Hz) and an instantaneous uplink peak data rate of 50Mb/s (2.5 bps/Hz) within a 20MHz uplink spectrum allocation. The peak data rates should then scale linearly with the size of the spectrum allocation. In case of spectrum shared between downlink and uplink transmission, EUTRA does not need to support the above instantaneous peak data rates simultaneously.7 Significantly reduced C-plane latency a) Transition time (excluding downlink paging delay and NAS signalling delay) of less than 100 ms from a camped-state, such as Release 6 Idle Mode, to an active state such as Release 6 CELL_DCH, in such a way that the user plane is established. b) Transition time (excluding DRX interval) of less than 50 ms between a dormant state such as Release 6 CELL_PCH and an active state such as Release 6 CELL_DCH.

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RAT: Radio Access Technology

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Capital expenditures (CAPEX or capex) are expenditures creating future benefits. A capital expenditure is incurred when a business spends money either to buy fixed assets or to add to the value of an existing fixed asset with a useful life extending beyond the taxable year. An operating expense, operating expenditure, operational expense, operational expenditure or OPEX is an ongoing cost for running a product, business, or system. Its counterpart, a capital expenditure (CAPEX), is the cost of developing or providing nonconsumable parts for the product or system. For example, the purchase of a photocopier involves CAPEX, and the annual paper, toner, power and maintenance costs represents OPEX. For larger systems like businesses, OPEX may also include the cost of workers and facility expenses such as rent and utilities.


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Evolved Packet Data Gateway: ePDG (Evolved Packet Data Gateway): The main function of the ePDG is to secure the data transmission with a UE connected to the EPC over an untrusted non-3GPP access. For this purpose, the ePDG acts as a termination node of IPsec tunnels established with the UE.


ARQ : Automatic Repeat Request HARQ: Hybrid Automatic Repet reQuest MIMO: Multiple Input- Multiple Output IGUAL A 3G: HARQ: HARQ solo se usa en 3g para HSDPA en adelante. IP transport layer: Qos Aware GTP.

Existen 3 tipos de algoritmos de scheduling: PF: proportional fair mas exigente: solo le da servicio a los user que tengan mejor C/I: CARRIER/ INTERFERENCE interactivos y background (NRT) AF: accurate forwarding intermedio: c/i target menos exigente que el PF  streaming (RT) RR: mas justo: a todos los usuarios los trata de atender sin importar el c/i.  voz (RT) Para LTE se usa solo PF porq LTE lleva servicios NRT.

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The following requirements are applicable to inter-working between E-UTRA and other 3GPP systems: a) E-UTRAN Terminals supporting also UTRAN and/or GERAN operation should be able to support measurement of, and handover from and to, both 3GPP UTRA and 3GPP GERAN systems correspondingly with acceptable impact on terminal complexity and network performance.

b) E-UTRAN is required to efficiently support inter-RAT measurements with acceptable impact on terminal complexity and network performance, by e.g. providing UE's with measurement opportunities through downlink and uplink scheduling. c) The interruption time during a handover of real-time services between EUTRAN and UTRAN is less than 300 msec d) The interruption time during a handover of non real-time services between E-UTRAN and UTRAN should be less than 500 msec

e) The interruption time during a handover of real-time services between EUTRAN and GERAN is less than 300 msec f) The interruption time during a handover of non real-time services between E-UTRAN and GERAN should be less than 500 msec

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g) Non-active terminals (such as one being in Release 6 idle mode or CELL_PCH) which support UTRAN and/or GERAN in addition to E-UTRAN shall not need to monitor paging messages only from one of GERAN, UTRA or EUTRA h) The interruption time during a handover between an E-UTRA broadcast stream and a UTRAN unicast stream providing the same service (e.g. same TV channel) is less than FFS. (Value to be agreed following SA guidance)

i) The interruption time during a handover between an E-UTRA broadcast stream and a GERAN unicast stream providing the same service (e.g. same TV channel) is less than FFS. (Value to be agreed following SA guidance) j) The interruption time during a handover between an E-UTRA broadcast stream and a UTRAN broadcast stream providing the same service (e.g. same TV channel) is less than FFS. (Value to be agreed following SA guidance) The above requirements are for the cases where the GERAN and/or UTRAN networks provide support for E-UTRAN handover. Reduction in network and terminal complexity and cost by not mandating support for the measurements and handovers to/from GERAN/UTRAN should be considered. Note: The interruption times above are to be considered as maximum values. These values may be revisited

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GUTI =GUMMEI + M-TMSI =(MCC + MNC + MMEI) + M-TMSI =(MCC + MNC + (MMEGI + MMEC)) + M-TMSI =(MCC + MNC + MMEGI) + S-TMSI GUMMEI：Globally Unique MME Identifier MMEI：MME Identifier

MMEGI: MME Group Identifier TMSI: Temporary Mobile Subscriber Identity MMEI=MMEGI + MMEC S-TMSI=MMEC + M-TMSI R8: 5 CATEGORIES R10: 8 categories



The eNB hosts the following functions: Functions for Radio Resource Management: Radio Bearer Control, Radio Admission Control, Connection Mobility Control, Dynamic allocation of resources to UEs in both uplink and downlink (scheduling); IP header compression and encryption of user data stream; Selection of an MME at UE attachment when no routing to an MME can be determined from the information provided by the UE; Routing of User Plane data towards Serving Gateway; Scheduling and transmission of paging messages (originated from the MME); Scheduling and transmission of broadcast information (originated from the MME or O&M); Measurement and measurement reporting configuration for mobility and scheduling; Scheduling and transmission of PWS (which includes ETWS: Earthquake and Tsunami Warning Systemand CMAS) messages (originated from the MME).



Mobility Management Entity (MME): The MME manages mobility, UE identities and security parameters. MME functions includes: NAS signalling; NAS signalling security; AS Security control; Inter CN node signalling for mobility between 3GPP access networks;

Idle mode UE Reachability (including control and execution of paging retransmission); Tracking Area list management (for UE in idle and active mode); PDN GW and Serving GW selection; MME selection for handovers with MME change; SGSN selection for handovers to 2G or 3G 3GPP access networks; Roaming; Authentication; Bearer management functions including dedicated bearer establishment; Support for PWS (which includes ETWS and CMAS) message transmission; Optionally performing paging optimisation.



RRC deals with all the signaling between the UE and the E-UTRAN in addition to transporting NAS signaling between the UE and the MME PDCP: IP header compression and sequencing / duplicate packet detection Encryption - Control Plane and User Plane. Integrity Checking - Control Plane. IP Header Compression - User Plane. Sequencing and Duplicate Detection - User Plane. Radio Link Control: TM (Transparent Mode) connectionless service UM (Unacknowledged Mode) - like that of TM +sequencing, segmentation and concatenation. AM (Acknowledged Mode) - this supports ARQ (Automatic Repeat Request) thereby operating in a connection orientated mode.  Medium Access Control: Mapping, Multiplexing ( generacion de TB), HARQ, radio resource allocation ( scheduling depending on the qos)  Physical Rate Matching: The rate matching for turbo coded transport channels is defined per coded block and consists of interleaving the three information bit streams dk(o), dk(1) and dk(2), followed by the collection of bits and the generation of a circular buffer Beamforming: single beam, dual beam (mejora de throuhgput) and multiple beam (mejora eficiencia espectral)



UE context: S1 link



X2 AP: Mobility management dentro del TA, load, error reporting, setting/ resett x2, configuration update. Stream Control Transmission Protocol: TX confiable, delivery secuencial, mejora la capacidad de recuperacion de la data, control de flujo, seguridad. GTP-U tunnels are used to carry encapsulated PDU (Protocol Data Unit) and signaling messages between endpoints. 1 TUNEL gtu p POR CADA eps bearer.


Time division multiple access (TDMA) is a channel access method for shared medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, one after the other, each using its own time slot. This allows multiple stations to share the same transmission medium (e.g. radio frequency channel) while using only a part of its channel capacity. TDMA is used in the digital 2G cellular systems such as Global System for Mobile Communications (GSM) Frequency Division Multiple Access or FDMA is a channel access method used in multiple-access protocols as a channelization protocol. FDMA gives users an individual allocation of one or several frequency bands, or channels. It is particularly commonplace in satellite communication. FDMA, like other Multiple Access systems, coordinates access between multiple users. Code division multiple access (CDMA) is a channel access method used by various radio communication technologies. CDMA is an example of multiple access, which is where several transmitters

can send information simultaneously over a single communication channel. This allows several users to share a band of frequencies. To permit this to be achieved without undue interference between the users CDMA employs spread-spectrum technology and a special coding scheme (where each transmitter is assigned a code).

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BPSK (also sometimes called PRK, phase reversal keying, or 2PSK) is the simplest form of phase shift keying (PSK). It uses two phases which are separated by 180° and so can also be termed 2-PSK. It does not particularly matter exactly where the constellation points are positioned, and in this figure they are shown on the real axis, at 0° and 180°. This modulation is the most robust of all the PSKs since it takes the highest level of noise or distortion to make the demodulator reach an incorrect decision. It is, however, only able to modulate at 1 bit/symbol (as seen in the figure) and so is unsuitable for high data-rate applications. Sometimes this is known as quaternary PSK, quadriphase PSK, 4-PSK, or 4QAM. (Although the root concepts of QPSK and 4-QAM are different, the resulting modulated radio waves are exactly the same.) QPSK uses four points on the constellation diagram, equispaced around a circle. With four phases, QPSK can encode two bits per symbol, shown in the diagram with gray coding to minimize the bit error rate (BER) — sometimes misperceived as twice the BER of BPSK. Quadrature amplitude modulation (QAM) is both an analog and a

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digital modulation scheme. It conveys two analog message signals, or two digital bit streams, by changing (modulating) the amplitudes of two carrier waves, using the amplitude-shift keying (ASK) digital modulation scheme or amplitude modulation (AM) analog modulation scheme. The two carrier waves, usually sinusoids, are out of phase with each other by 90° and are thus called quadrature carriers or quadrature components — hence the name of the scheme. The modulated waves are summed, and the resulting waveform is a combination of both phase-shift keying (PSK) and amplitude-shift keying (ASK), or (in the analog case) of phase modulation (PM) and amplitude modulation. In the digital QAM case, a finite number of at least two phases and at least two amplitudes are used. PSK modulators are often designed using the QAM principle, but are not considered as QAM since the amplitude of the modulated carrier signal is constant. QAM is used extensively as a modulation scheme for digital telecommunication systems. Arbitrarily high spectral efficiencies can be achieved with QAM by setting a suitable constellation size, limited only by the noise level and linearity of the communications channel.

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Automatic Repeat reQuest (ARQ), also known as Automatic Repeat Query, is an error-control method for data transmission that uses acknowledgements (messages sent by the receiver indicating that it has correctly received a data frame or packet) and timeouts (specified periods of time allowed to elapse before an acknowledgment is to be received) to achieve reliable data transmission over an unreliable service. If the sender does not receive an acknowledgment before the timeout, it usually retransmits the frame/packet until the sender receives an acknowledgment or exceeds a predefined number of re-transmissions. Hybrid automatic repeat request (hybrid ARQ or HARQ) is a combination of high-rate forward error-correcting coding and ARQ error-control. In standard ARQ, redundant bits are added to data to be transmitted using an errordetecting (ED) code such as a cyclic redundancy check (CRC). Receivers detecting a corrupted message will request a new message from the sender. In Hybrid ARQ, the original data is encoded with a forward error correction (FEC) code, and the parity bits are either immediately sent along with the message or only transmitted upon request when a receiver detects an erroneous message. The ED code may be omitted when a code is used that can perform

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both forward error correction (FEC) in addition to error detection, such as a Reed-Solomon code. The FEC code is chosen to correct an expected subset of all errors that may occur, while the ARQ method is used as a fall-back to correct errors that are uncorrectable using only the redundancy sent in the initial transmission. As a result, hybrid ARQ performs better than ordinary ARQ in poor signal conditions, but in its simplest form this comes at the expense of significantly lower throughput in good signal conditions. There is typically a signal quality cross-over point below which simple hybrid ARQ is better, and above which basic ARQ is better. HARQ: HSDPA EN 3G.

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Spectrum flexibility a) Support for spectrum allocations of different size 1) E-UTRA shall operate in spectrum allocations of different sizes, including 1.25 MHz, 1.6MHz (intended primarily for use due spectrum compatibility on the bands with 1.28 Mcps TDD), 2.5 MHz, 5 MHz, 10 MHz, 15 MHz and 20 MHz. in both the uplink and downlink. Operation in paired and unpaired spectrum shall be supported. 2) E-UTRA shall enable the flexibility to support broadcast transmission in both modes: “Downlink–only”, and “Downlink and Uplink” allowing an optimised usage of the available spectrum. 3) E-UTRA shall enable the flexibility to modify the radio resource allocation for broadcast transmission according to specific demand or operator’s policy. Eg: Emergency situation, special local or global events. 4) Unnecessary fragmentation of technologies for paired and unpaired band operation shall be avoided. This shall be achieved with minimal additional complexity. b) Support for diverse spectrum arrangements 1) The system shall be able to support (same and different) content delivery

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over an aggregation of resources including Radio Band Resources (as well as power, adaptive scheduling, etc) in the same and different bands, in both uplink and downlink and in both adjacent and non-adjacent channel arrangements. 2) The degree to which the above requirement is supported is conditioned on the increase in UE and network complexity and cost. 3) A "Radio Band Resource" is defined as all spectrum available to an operator.

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Note instruction Font: FrutigerNext LT Regular Font Size: 11 Item symbol Size: 70% Row Space: 1.25 Segment: 3 pound





OFDM has a history of 40 years in application, and it is initially used in radio communications in military. In 1950s, American military established the first multi-carrier modulation system. In 1970s, the OFDM system with massive subcarriers appeared. However, mass commercial application did not appear due to the system complexity and high costs.

In 1990s, with the development of digital communication technologies, IFFT on the OFDM transmitter side and FFT on the OFDM receiver side reduces system complexity, enabling OFDM to be widely used.



S-P：串并转换



PAPR: sumatoria de los simbolos en un t especifico



In traditional FDMA transmission, a channel is divided into multiple independent sub-channels to transmit data streams in parallel, and the subchannels are separated by a group of filters on the receiver. This method is simple and direct while the spectral efficiency is low because guard-bands are required between sub-channels, which is difficulty to achieve by filters. However, subcarriers in the OFDM system are overlapping and orthogonal, which greatly improves the spectral efficiency compared with common FDA systems, as shown in the preceding figure. The orthogonal modulation and demodulation in each sub-channel can be performed using IDFT and DFT. For systems with large N value, FFT can be used. IFFT and FFT are easy to perform with the development of large-scale integrated circuit and DSP technologies, as shown in the preceding figure.



Withstand: RESISTENCIA ante el ambiente multipath. 2G: TRAINING SEQUENCE 3G: RAKE RECEIVER 4G: CP



A Cyclic Prefix is utilized in most OFDM systems to combat multipath delays. The extended Cyclic Prefix is designed for larger cells pero se reduce la capacidad, porq se reduce la cantidad de simbolos por segundo.



Deep fading does not occur simultaneously in all subcarriers due to the frequency selectivity. Therefore, dynamic bit or subcarrier allocation technology can be used to utilize the sub-channels with high SNR and improve the system performance. In a multi-user system, a subcarrier that is in poor performance for a user probably is in good performance for another user. Therefore, a sub-channel is not disabled unless it is in poor performance for all users, which occurs at a low probability. The single-carrier system performs adaptive modulation and coding (AMC) based on the average SINR in the entire system, while the multi-carrier system performs AMC based on the average SINR in different frequency bands. MCS: modulation and coding squeme.



Orthogonality is required because spectrums of sub-channels overlap each other. Frequency offset of radio signals, such as Doppler Shift, can be caused by radio channel change with time. In addition, the difference between transmitter carrier frequency and receiver oscillator frequency can also cause frequency offset, destroying the orthogonality of subcarriers in the OFDM system. As a result, inter-carrier interference (ICI) among sub-channels is generated, deteriorating the BER of the system. The vulnerability to the frequency offset is the primary disadvantage of the OFDM system. Foffset es el corrimiento de la fcentral de cada subcarrier



Different from single-carrier systems, multi-carrier system outputs combined signals of multiple sub-channels. If these signals are in the same phase, the power of combined signals must be higher than the average power of signals, resulting in a high PAR. To reduce the high PAR, high linearity of the PA in the transmitter is required. If the dynamic range of the PA cannot adjust to the signal change, signals are deformed, changing the spectrum of the combined signals. As a result, the orthogonality of signals in multiple sub-channels is destroyed, leading to interference and deteriorated system performance. Si forzo el enodeb a un nivel de potenica muy alto, las señales se deforman, perdiendo la ortogonalidad y generando interferencia.


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The multiple-access technology is used to distinguish users in a system, including FDMA, TDMA, and CDMA. FDMA: The first-generation mobile telecommunications uses FDMA, which divides a frequency into multiple channels and is easy to deploy. However, the system capacity is limited due to limited frequency resources. TDMA: Based on FDMA, TDMA divides each frequency in both the frequency domain and time domain, increasing the system capacity and improving the spectral efficiency. CDMA: CDMA distinguishes users based on the frequency, time, and code. In this way, the system capacity is further improved. However, CDMA has a high requirement in interference resistance technology. In terms of capacity, the capacity of a TDMA system is four to six times as large as that of an FDMA system while the capacity of a CDMA system is ten to twenty times as large as that of an FDMA system. The system capacity is closely related to the carrier-to-interference ratio (CIR), which refers to a ratio of the strength of a carrier signal to the strength of an interfering signal in a radio channel. If a large CIR is required, the interference resistance of the system is weak, and the system capacity is small. In terms of deployment, FDMA is the easiest one while CDMA is the most complicated one. Confidential Information of Huawei. No Spreading Without Permission




Compared with CDMA, OFDMA has the following advantages: Effectively eliminating multipath interference in radio communications by using cyclic prefixes Achieving orthogonal frequency multiplexing between users with an ensured spectral efficiency Combining OFDM and MIMO Technology Supporting frequency link adaptation and multi-user scheduling OFDMA is a multiple-access modulation scheme based on resources in the time and frequency domains. The scheduling resource in the frequency domain is subcarriers and the smallest unit in the time domain is slot.



Compared with OFDMA, SC_FDMA has the following advantages: Lower PAPR, facilitating the design of UE PAs Achieving orthogonal frequency multiplexing between users with an ensured spectral efficiency Achieving multiplexing by using DFT and orthogonal subcarrier mapping Supporting frequency link adaptation and multi-user scheduling



DFT: Reacomodacion de las señales de un mismo user para que queden en subcarriers seguidas a traves de la insercion de 0s. Como hacve esta insercion de 0s?






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SC-FDMA also performs better when in larger cells.







NDL= EARFCN: evolved absolute radio frequency channel number FDL= FRECUENCIA DEL OPERADOR, frecuencia central. NOffs-DL is the lowest defined EARFCN for the band El Raster Channel es de 100 KHz en todos los canales






Subframe 1 canales. Ts: periodo basico The symbol (Ts) consists of a guard period, i.e. the cyclic prefix, and the Tb data duration which is 2048 LTE time units for both the normal and extended 15kHz option Demostracion: http://www.lteportal.com/Files/MarketSpace/Download/325_523commsdesign.pdf Ts: Tsample 15360: numero de samples que se transmiten en 7 symbols. CP FIRST= 160 USEFUL SYMBOL= 2048 CP = 144 SAMPLES Total de samples= 15360.


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IPR (Intellectual Property Rights) Comments concerning IPR: -UMTS: high number of essentials and many IPR holders, very aggressive licensing policy (Qualcomm) by holders without product business, no effective IPR regulation (forming licensing pools) in place -LTE /SAE: also many patents and IPR holders, but aggressive ones are not so dominant, most patents hold by infrastructure & terminal vendors, increased IPR awareness /lessons learned from 3G), additional IPR regulations planed via NGNMN (early declaration of IPR licensing fees, forming licensing pools possible) -WIMAX: nearly same number of patents and patent holders as for LTE, but many of them will not provide Wimax products, expectation of aggressive licensing (Qualcomm, Wi-Lan), licensing pool initiated by INTEL up till now not successful, slightly lower number of essential patents expected than for LTE Economy of scale: -UMTS/HSPA: designed for evolution of GSM networks, therefore new terminals will contain UMTS/HSPDA too  leverage of GSM footprint, same is for Basestations (site and component sharing) /and Core network entities -Wimax: mainly driven from Notebook market (INTEL Chipsets will include

WIMAX),i.e. datacards. dedicated handsets expected to follow, but extend

-LTE: GSM and UMTS network footprint can be leveraged. High terminal volumes can be expected (GSM/UMTS/LTE multimode terminals from beginning), also platform sharing in Basestations. Spectrum availability and cost impact: -UMTS/HSPA: paired spectrum assign in 2GHz band in many regions, in Europe partly high costs due to auctions, continuous 5MHz bandwith required

-Wimax: currently suited for TDD spectrum, in 3,5 Ghz band and in some

regions probably also in 2,5 Ghz band as well as in unlicensed bands, more cost intensive due to 3,5 Ghz band -LTE: planned for 2,6 Ghz band (W-Cdma extension bands) and refarming of GSM frequency bands (scalable bandwitdth) Terminal variety: -UMTS/HSPA: designed for evolution of GSM networks, therefore also broad availability of GSM/UMTS multimode terminals -Wimax: currently starting with datacards of Notebooks only, but terminals

planned, unsure how many terminals vendors will provide Wimax terminal, especially which multimode capabilities exist -LTE: as evolution of GSM and UMTS network a wide variety of terminals can be expected, probably most of them supporting GSM/UMTS as well Voice performance: -UMTS/HSPA: Circuit switched was as well as Voice over HSPA in future -Wimax: No circuit switched voice, VOIP only, pure QoS management

-LTE: VoIP only, but lowest latency in Air-I/F and network due to flat architecture and QoS mechanism, at the beginning also directing of voice traffic to GSM/UMTS overlay network possible Broadband data performance:

-UMTS/HSPA: up to 14 Mbit/s DL, 5,6 UL -Wimax: high data performance upt to 50 Mbits/s

-LTE: highes data performance up to 160 Mbit/s (DL) and 50 Mbit/s UL, high

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spectral efficiency Lean Architecture: -UMTS/HSPA: 4 Node architecture (Node-B, RNC; SGSN, GGSN) -Wimax: 3 Node architecture (AP, ASN-GW, CSN-GW)

-LTE: Ultra flat architecture 2 Nodes only (eNodeB, SAE-GW) Compatibility with existing systems: UMTS/HSPA: internat. roaming, HO to GSM systems Wimax: currently no IW to other systems, difficult to implement LTE: Full IW with GSM /UMTS networks will be defined and implemented, also IW to other systems like WIMAX /CDMA2000 planned

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Nokia_1 LTE Overview Nokia

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