Data transmission and reception method and system

Abstract

A method realized by a MIMO OFDM transmitter (100) of a base station for transmitting data to at least a first user equipment (21) having MIMO OFDM receiver (200) using a first service type having a first numerology (M) and to a second user equipment (22) having MIMO OFDM receiver (200) using a second service type having a second numerology (N), where said first numerology (M) and said second numerology (N) are different than each other, characterized by comprising following steps: receiving at least a first input signal having n number of OFDM symbols to be transmitted to the first user equipment (21); applying n number of inverse fast Fourier transform (IFFT) to the first input signal, adding a first virtual cyclic prefix (411) to each OFDM sample and generating first OFDM symbols (410) for the first service; applying a first fast Fourier transform (FFT) having larger FFT size than n and m to first OFDM symbols; receiving (410) at least a second input signal having m number OFDM samples to be transmitted to the second user equipment (22); applying m number of inverse fast Fourier transform (IFFT) to the second input signal, adding a second virtual cyclic prefix (421) to each OFDM sample and generating second OFDM symbols (420) for the second service; where first cyclic prefix and second cyclic prefix are different than each other; and first cyclic prefix and second cyclic prefix are lower in size than the largest cyclic prefix in a predetermined numerology table; applying the first fast Fourier transform (FFT) to second OFDM symbols (420); multiplexing (420) first OFDM symbols (410) and second OFDM symbols (420) depending on number of transmitting antennas (190); applying Inverse Fast Fourier Transform (IFFT) to multiplexed first OFDM symbols (410), second OFDM symbols (420), adding an encapsulating prefix (310) and generating encapsulating OFDM symbols (300) for each transmitting antenna; transmitting encapsulating OFDM symbols (300) symbols through transmitting antennas (190).

Description

[0001] DATA TRANSMISSION AND RECEPTION METHOD AND SYSTEM

[0002] TECHNICAL FIELD

[0003] The invention relates to a MIMO OFDM transmitter of a base station for transmitting data to at least a first user equipment having MIMO OFDM receiver using a first service type having a first numerology and to a second user equipment having MIMO OFDM receiver using a second service type having a second numerology; a transmitting and receiving method thereof; and MIMO OFDM receiver of a user equipment.

[0004] BACKGROUND

[0005] For wide-band channels with multiple taps, precoding in the time domain results in additional complexity, and one way to overcome this problem is by using an additional baseband operation, which is Orthogonal Frequency Division Multiplexing (OFDM) precoding (Fast Fourier Transform (FFT) and cyclic prefix (CP) addition operations). This allows us to split the channel into parallel channels with smaller bandwidth occupation, and as a result, frequencyflat response over such channels is obtained. Assuming a multiple-input-multiple-output (MIMO) system, at each tone, or subcarrier, we have an image of the channel matrix. Therefore, precoding is performed for each subcarrier based on its channel realization.

[0006] An OFDM modulator (demodulator) has two cascaded operations: Fourier transformation and cyclic redundancy addition (removal). At transmitter side, it is a precoding with two cascaded operations; inverse fast Fourier transformation (IFFT) is performed then redundancy is added. At receiver side, on the other hand, the fast Fourier transform (FFT) is used after cyclic redundancy removal.

[0007] All user equipment (UEs) are multiplexed based on the frequency-domain channel realizations on carriers seen by all communication terminals. On the other hand, for multi-service systems, UEs belonging to different services use different Fourier transformation sizes, which means they will not experience exactly the same frequency-domain channel representation. As a result, each service requires a separate OFDM pre-coder at the receiver side and precoding will not be a straightforward process. The precoding at each service side does not necessarily end in complete interference elimination as OFDM signals are distorted during CP removal. The main reason for that is using a different number of samples in the frequency domain for the same allocated band. Those services with a larger number of samples (i.e., larger FFT size) not interfere on UEs belonging to services with smaller sizes by proper precoding as they consider all their subcarriers. On the other hand, those with smaller FFT size will interfere on UEs with larger OFDM symbols as part of the subcarriers seen by the latter is not considered in precoding for the former.

[0008] In wireless communication systems that support multiple subcarrier spacings (numerologies) such as 5G, inter-numerology interference (INI) can occur when signals transmitted using different subcarrier spacings overlap in the frequency domain. INI is a type of interference that can occur between different numerologies or subcarrier spacing. It can degrade the signal quality and affect the performance of the wireless communication system. The cause of INI is that different numerologies use different subcarrier spacings, and the subcarriers of each numerology are not orthogonal to the subcarriers of the other numerologies. Therefore, when signals transmitted using different numerologies overlap in the frequency domain, they can interfere with each other, causing INI.

[0009] For above mentioned problem, there are some solutions in the prior art. To deliver information to each UE independently while eliminating interference, one solution is precoding at the transmitter side. Precoding might also be combined, to a given extent, with combining at the UEs’ sides. Both precoding and combining are basically beamforming based on the estimated channel state information (CSI) to create eigen channels, which have minimum interference (i.e., channel matrix diagonalization).

[0010] Precoding is performed for each subcarrier based on its channel realization. However, the main problem is that unmatching subcarriers will introduce interference as precoding will not be performed to all seen subcarriers by UEs. In addition, at a given user belonging to one service, received OFDM signals from other services get distorted during CP removal, thus, the classical OFDM-MIMO transceiver becomes unsuitable. Consequently, precoding will not remove INI for some services.

[0011] One approach for the mentioned INI problem is INI pre-cancellation as given in X. Cheng, R. Zayani, H. Shaiek and D. Roviras, "Inter-Numerology Interference Analysis and Cancellation for Massive MIMO-OFDM Downlink Systems," in IEEE Access, vol. 7, pp. 177164-177176, 2019, doi: 10.1 109 / ACCESS.2019.2957194. In this solution, INI from small-FFT-size UE to large-FFT-size UE is calculated in advance with the knowledge of the MIMO channel response and signals after the precoding for the small-FFT-size UE. After calculation, it is removed from the transmitted signal of users with larger FFT size so that the received signal is a signal without interference. Greater selectivity and / or larger difference between different FFT sizes leads to greater interference.

[0012] Another approach for is INI elimination with spatial multiplexing in H. Son, G. Kwon, H. Park and J. S. Park, "Massive MIMO Precoding for Interference-Free Multi-Numerology Systems," in IEEE Transactions on Vehicular Technology, vol. 71 , no. 9, pp. 9765-9780, Sept. 2022, doi: 10.1 109 / TVT.2022.3182408. This approach gives a complete elimination of INI with relaxed accurate channel knowledge requirement as in the previous approach. In this approach, the characteristic of massive MIMO channel is exploited ensure orthogonality and prevent INI. However, similar to the approach in previous solution, the solution has significantly increased system complexity. It is required to have RF chains more than every used CP samples for every user in the network, which requires increased system resources, increased hardware resources.

[0013] All the problems mentioned above have made it necessary to make an innovation in the relevant technical field as a result.

[0014] BRIEF DESCRIPTION OF THE INVENTION

[0015] The present invention relates to a transmitting method, a receiving method, a transmitter and receiver to eliminate the above-mentioned disadvantages and bring new advantages to the relevant technical field.

[0016] An object of the invention is to eliminate INI between services having different numerologies.

[0017] Another object of the invention is to reduce system resources used while transmitting and receiving MIMO OFDM signals.

[0018] To achieve all the objects mentioned above and that will emerge from the following detailed description, the present invention relates to a method realized by a MIMO OFDM transmitter of a base station for transmitting data to at least a first user equipment having MIMO OFDM receiver using a first service type having a first numerology and to a second user equipment having MIMO OFDM receiver using a second service type having a second numerology, where said first numerology and said second numerology are different than each other, Accordingly, it is characterized by comprising following steps: receiving at least a first input signal having n number of OFDM symbols to be transmitted to the first user equipment; applying n number of inverse fast Fourier transform (IFFT) to the first input signal, adding a first virtual cyclic prefix to each OFDM sample and generating first OFDM symbols for the first service; applying a first fast Fourier transform (FFT) having larger FFT size than n and m to first OFDM symbols; receiving at least a second input signal having m number OFDM samples to be transmitted to the second user equipment; applying m number of inverse fast Fourier transform (IFFT) to the second input signal, adding a second virtual cyclic prefix to each OFDM sample and generating second OFDM symbols for the second service; where first cyclic prefix and second cyclic prefix are different than each other; and first cyclic prefix and second cyclic prefix are lower in size than the largest cyclic prefix in a predetermined numerology table; applying the first fast Fourier transform (FFT) to second OFDM symbols; multiplexing first OFDM symbols and second OFDM symbols depending on number of transmitting antennas; applying Inverse Fast Fourier Transform (IFFT) to multiplexed first OFDM symbols, second OFDM symbols, adding an encapsulating prefix and generating encapsulating OFDM symbols for each transmitting antenna where encapsulating cyclic prefix is the largest in size in said predetermined numerology table;; transmitting encapsulating OFDM symbols symbols through transmitting antennas. Thus, INI between different services having different numerology is eliminated.

[0019] A possible embodiment of the invention is characterized in that comprising the step of: reducing virtual cyclic prefixes by at least first ratio that is recorded on a memory means.

[0020] Invention is also a method realized by a MIMO OFDM receiver of a user equipment using a first service type for receiving data from a MIMO OFDM transmitter of a base station. Accordingly, it is characterized by comprising steps of: receiving encapsulating OFDM symbols; removing an encapsulating cyclic prefix from said encapsulating OFDM symbols and acquiring first OFDM symbols where encapsulating prefix is the largest in size in said predetermined numerology table; removing a first virtual cyclic prefix from OFDM symbols where first cyclic prefix is lower in size than the largest cyclic prefix in said predetermined numerology table; applying fast Fourier transform (FFT) and acquiring a first input signal.

[0021] Invention is also a MIMO OFDM transmitter of a base station for transmitting data to at least a first user equipment having MIMO OFDM receiver using a first service type having a first numerology and to a second user equipment having MIMO OFDM receiver using a second service type having a second numerology, where said first numerology and said second numerology are different than each other. Accordingly it is characterized by comprising; multiple receive antennas configured to receive at least a first input signal having n number of OFDM symbols to be transmitted to the first user equipment and at least a second input signal having m number of OFDM symbols to be transmitted to the second user equipment; at least a S1 first IFFT module configured to apply n number of inverse fast Fourier transform (IFFT) to the first input signal; at least a S1 V-CP adder (141 ) configured to add a first virtual cyclic prefix to the first input signal, and generating first OFDM symbols for the first service; at least a S2 first IFFT module configured to apply m number of inverse fast Fourier transform (IFFT) to the second input signal; at least a S2 V-CP adder configured to add a second virtual cyclic prefix to the second input signal, and generating second OFDM symbols for the second service; where first cyclic prefix and second cyclic prefix are different than each other; and first cyclic prefix and second cyclic prefix are lower in size than the largest cyclic prefix in a predetermined numerology table; at least a S1 FFT module configured to apply a first fast Fourier transform (FFT) to first OFDM symbols; at least a S2 FFT module configured to apply the first fast Fourier transform (FFT) to second OFDM symbols; a precoding unit configured to multiplex first OFDM symbols and second OFDM symbols; at least an encapsulating IFFT module provided for each transmitting antenna configured to apply Inverse Fast Fourier Transform (IFFT) to multiplexed first OFDM symbols and second OFDM symbols; at least an E-CP adder provided for each transmitting antenna and configured to add an encapsulating prefix to multiplexed first OFDM symbols and second OFDM symbols and generating a encapsulating OFDM symbols for each transmitting antenna; multiple transmitting antenna configured to transmit encapsulating OFDM symbols.

[0022] Invention is also a MIMO OFDM receiver of a user equipment using a first service type for receiving data from a MIMO OFDM transmitter of a base station, characterized by comprising; equipment receive antennas configured to receive first encapsulating OFDM symbols; at least an E-CP remover configured to remove an encapsulating cyclic prefix from said encapsulating OFDM symbols and acquire OFDM symbols where encapsulating prefix is the largest in size in said predetermined numerology table; at least a S1 V-CP remover configured to remove a first virtual cyclic prefix from OFDM symbols where first cyclic prefix is lower in size than the largest cyclic prefix in said predetermined numerology table; at least an equipment S1 FFT module configured to apply fast Fourier transform (FFT) and acquire a first input signal.

[0023] BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a drawing illustrating INI in prior art systems when subcarriers are not matched for different services as FFT sizes are different for the same bandwidth. Figure 2 is a drawing illustrating INI in prior art systems, when received signals from other services at a user belonging to one service are distorted during CP removal as they have different sizes and their CPs do not match.

[0025] Figure 3 is a drawing illustrating top schematic view of MIMO OFDM transmitter of a base station and MIMO OFDM receiver of user equipment.

[0026] Figure 4 is a drawing illustrating encapsulated OFDM symbol, first OFDM symbols and second OFDM symbols.

[0027] DETAILED DESCRIPTION OF THE INVENTION

[0028] In this detailed description, the subject matter is explained with references to examples without forming any restrictive effect only in order to make the subject more understandable.

[0029] Reference is made to Third Generation Partnership Project (3GPP) system, in accordance with embodiments of the present disclosure. The present application employs abbreviations, terms and technology defined in accord with Third Generation Partnership Project (3GPP) technology standards, including the following standards and definitions. 3GPP technical specifications (TS) and technical reports (TR) incorporated in their entirety by reference herein, define the related terms and architecture reference models that follow.

[0030] OFDM: Orthogonal Frequency Division Multiplexing

[0031] MIMO: Multiple Input Multiple Output

[0032] CP: Cyclic Prefix

[0033] FFT: Fast Fourier Transform

[0034] IFFT: Inverse Fast Fourier Transform

[0035] TP: Transmission Point

[0036] UE: User Equipment

[0037] WRAN: Wireless Radio Access Network

[0038] NR: New Radio

[0039] In a conventional OFDM-MIMO transceiver, each antenna port has its own FFT and CP operation at both the transmitter and receiver sides. The multi-tap channel for every possible path between transmit and receive ports is converted into parallel channels over subcarriers. Equivalently, every subcarrier has a single-tap MIMO channel, and those channels for adjacent subcarriers are correlated. If all users use the same subcarrier spacing, i.e., same service, then their single-tap MIMO channels in the frequency domain match as they have the same number of subcarriers. Thus, they can be multiplexed spatially over each subcarrier as if it is a classical MIMO channel. In multi-service systems, users belonging to different services have different subcarrier spacings and CP sizes. If the conventional OFDM-MIMO transceiver were to be used, then each service should have its own FFT and CP operations at every transmitting port, which increases complexity. Referring to figure 2, In the frequency domain, subcarriers are not matched for different services as FFT sizes are different for the same bandwidth. So precoding is not sufficient to multiplex all users spatially, and the result is inter-numerology interference (INI). Additionally, referring to figure 2, received signals from other services at a user belonging to one service are distorted during CP removal as they have different sizes and their CPs do not match. In figure 2 FFT windows (600) for a first numerology (M) and a second numerology (N) is shown. Cyclic Prefix of First Numerology (M) (Mcp) and Cyclic Prefix of Second Numerology (N) (Nep) are different than each other.

[0040] Referring to figure 1 , present invention is a MIMO OFDM transmitter (100) of a base station for transmitting data to multiple user equipment (for instance; first user equipment (21 ) and second user equipment) (22) that use different services than each other where said services uses different numerologies and a method thereof. Present invention is also a MIMO OFDM receiver (200) of a user equipment for receiving such data and a method thereof.

[0041] User equipment refers to the end-user device in a wireless communication system that is used to send and receive data over the wireless network. UE can be any device that has a wireless interface, such as a mobile phone, tablet, laptop, or other portable device. Base station, also known as a cell site or cell tower, is a component in a wireless communication system that connects user equipment (UE) to the core network. The base station includes a transmitter and receiver that operate on specific frequency bands and use specific communication protocols, such as LTE or 5G. The base station communicates with the UE to establish and maintain a connection for data transmission.

[0042] MIMO OFDM transmitter comprises receive antennas (1 10) that is configured to receive input signals to be transmitted to user equipment. In more detail, receive antennas (110) is configured to receive at least a first input signal having n number of OFDM samples to be transmitted to a first user equipment (21 ) using a first service where said first service has a first numerology; (M) and receive a second input signal having m number of OFDM samples to be transmitted to a second user equipment (22) using a second service where first service has a second numerology (N). First numerology (M) and second numerology (N) are different than each other. MIMO OFDM transmitter comprises a power allocation unit (120) for allocating power of first input signal and second input signal.

[0043] MIMO OFDM transmitter (100) comprises a S1 first IFFT module (131 ) that is configured to apply n number of IFFT to first input signal. MIMO OFDM transmitter (100) comprises a S1 first V-CP adder which is configured to add a first virtual cyclic prefix (411 ) to first input signal and acquire first OFDM symbols (410) (Figure 4). MIMO OFDM transmitter (100) comprises a

[0044] 51 FFT module (151 ) (241 ) which is configured apply a first FFT to first OFDM symbol (410).

[0045] First FFT is larger than FFT first signal and second signal’s initial FFT.

[0046] MIMO OFDM transmitter (100) comprises a S2 first IFFT module (132) that is configured to apply m number of IFFT to second input signal. MIMO OFDM transmitter (100) comprises a

[0047] 52 first V-CP adder is which is configured to add a second virtual cyclic prefix (421 ) to second input signal and acquire second OFDM symbols (420) (Figure 4). MIMO OFDM transmitter (100) comprises a S2 FFT module (152) (242) which is configured apply the first FFT to second OFDM symbol (420). First V-CP and second V-CP are cyclic prefixes that are lower or equial in size than a largest numerology in a predetermined numerology table. Such table for 5g NR is given in table 1.

[0048] The size of the numerology in wireless communication systems refers to the subcarrier spacing between adjacent subcarriers, and it determines the bandwidth of each subcarrier and the overall bandwidth of the signal. For instance, first numerology (M) and second numerology (N) may be two of numerology 0-3. Since subcarrier spacing is the highest.

[0049] Table 1 In this description components for generating transmission signals suitable for first service and second service are given as example. Depending on the service and user count, IFFT modules, V-CP adders and FFT modules are increased and can be in any suitable number.

[0050] MIMO OFDM transmitter (100) comprises plurality of transmitting antennas (190) that is configured to transmit data to user equipment.

[0051] MIMO OFDM transmitter further comprises a precoding unit (160). Precoding unit (160) multiplexes first OFDM symbols (410) and second OFDM symbols (420). MIMO OFDM transmitter (100) comprises at least a second IFFT module (171 ) for each transmitting antenna (190) that is configured to apply IFFT to multiplexed first OFDM symbols (410) and second OFDM symbols (420).

[0052] MIMO OFDM transmitter (100) comprises, at least an E-CP adder (181 ) provided for each transmitting antenna (190) that adds an encapsulating cyclic prefix (310) to multiplexed first OFDM symbols (410) and second OFDM symbols (420). Encapsulating cyclic prefix (310) is larger than or equal to first virtual cyclic prefix (411 ) and second virtual cyclic prefix (421 ). Preferably encapsulating cyclic prefix (310) is the largest in size in said predetermined numerology table. Referring to table 1 , encapsulating cyclic prefix (310) may be Numerology 4 in such numerology table. Then, transmitting antennas (190) transmits encapsulating OFDM symbols that they are assigned to.

[0053] Thus virtual channels are created for users with no interference to others, whether they are in the same or different service. It represents an OFDM modulator with actual OFDM symbols, along with their CPs, as data samples. The output of S1 V-CP adder (141 ) and S1 V-CP adder (141 ) are first OFDM symbol (410) and second OFDM symbols (420) with an attached related virtual cyclic prefixes. It is taken back to frequency domain to be precoded as if it is data symbols. However, it is not only one symbol taken back to the frequency domain but multiple ones. The size of an OFDM symbol in service i is Mt, but the size of that FFT block, second precoding module, taking time samples back to frequency domain is M0- M0should be equal to the size of multiple OFDM symbols along with their CPs; M0= L i (M_i + C i), where L i is the number of encapsulated OFDM symbols in c- {th} service and is the length of V-CP attached to each one. Encapsulated OFDM symbols has multiple OFDM symbols. IFFT with CP addition followed by bigger FFT operation acts as if samples are taken back to frequency domain with higher sampling resolution. This may be implemented directly with one linear transformation.

[0054] In a possible embodiment, virtual cyclic prefixes are variable. Power allocation unit (120) is configured to shorten cyclic prefixes by a predetermined ratio. Said predetermined ratio is known to both user equipment and base station. Predetermined ratio may be dynamically calculated based on user equipment’s channel status.

[0055] Shortening allows first OFDM symbols (410) and second OFDM symbols (420) to shorten, thus reducing overheading. Such information may fed back to the user equipment after uplink channel estimation possibly at two different rates; user equipment might be informed at the small-scale fading rate, or at the large-scale fading rate. In the former, the base station informs back each service of its variable cyclic prefix size after each channel estimation. In the latter, the variable cyclic prefix size changes whenever the E-CP changes, depending only on the delay spread at each service. In another possible embodiment possibility is that users, after channel estimation, report back a shortening indicator or shortening matrix indicator to inform base station of the proper shortening. Base station, in its turn, decides on the shortening for all multiplexed users based on the reports received from the user equipment.

[0056] Referring to figure 3, present invention is also a MIMO OFDM receiver (200) of a user equipment for receiving encapsulating OFDM symbols without INI.

[0057] MIMO OFDM receiver (110) comprises equipment receive antennas (1 10) that is suitable for receiving encapsulating OFDM symbols. For instance, MIMO OFDM receiver (200) may belong to a user equipment that uses first service. MIMO OFDM receiver (200) comprises a S1 E-CP remover (221 ) for removing first encapsiulating OFDM symbols and acquires first OFDM symbols (410). MIMO OFDM receiver (200) comprises a S1 V-CP remover (231 ) for removing first virtual cyclic prefix (411 ) from first OFDM symbols (410) and acquiring input signal. MIMO OFDM receiver (200) further comprises an equipment S1 FFT module (241 ) for applying FFT to input signal. Thus, user equipment can receive and process input signal in a MIMO system that transmits signals belonging to different services that has different numerologies without INI.

[0058] A second user equipment (22) that uses a second service type that uses different numerology may comprise CP remover specific to that service. User equipment may upgrade its V-CP remover with the predetermined ratio information received from base station as described above.

[0059] The scope of protection of the invention is specified in the attached claims and cannot be limited to those explained for sampling purposes in this detailed description. It is evident that a person skilled in the art may exhibit similar embodiments in light of the above-mentioned facts without drifting apart from the main theme of the invention.

[0060] REFERENCE NUMBERS GIVEN IN THE FIGURE

[0061] 100 MIMO OFDM Transmitter

[0062] 110 Receive antennas

[0063] 120 Power allocation unitPower allocating unit

[0064] 131 S1 first IFFT module

[0065] 132 S2 first IFFT module

[0066] 141 S1 V-CP adder

[0067] 142 S2 V-CP adder

[0068] 151 S1 FFT module

[0069] 152 S2 FFT module

[0070] 160 Precoding unit

[0071] 171 Encapsulating IFFT module

[0072] 181 E-CP adder

[0073] 190 Transmitting antenna

[0074] 21 First User Equipment

[0075] 22 Second User Equipment

[0076] 200 MIMO OFDM Receiver

[0077] 210 Equipment receiver means

[0078] 221 S1 E-CP remover

[0079] 231 S1 V-CP remover

[0080] 241 Equipment S1 FFT module

[0081] 201 Second MIMO OFDM Receiver

[0082] 210 Equipment receiver means

[0083] 222 S2 E-CP remover

[0084] 232 S2 V-CP remover

[0085] 242 Equipment S2 FFT module

[0086] 300 Encapsulating OFDM Symbol

[0087] 310 Encapsulating Cyclic Prefix

[0088] 410 First OFDM Symbol

[0089] 411 First virtual cyclic prefix

[0090] 420 Second OFDM Symbol

[0091] 421 Second virtual cyclic prefix

[0092] 510 First Signal

[0093] 520 Second Signal 600 FFT Window

[0094] M First Numerology

[0095] N Second Numerology

[0096] Mcp Cyclic Prefix of First Numerology Nep Cyclic Prefix of Second Numerology

Claims

CLAIMS1 . A method realized by a MIMO OFDM transmitter (100) of a base station for transmitting data to at least a first user equipment (21 ) having MIMO OFDM receiver (200) using a first service type having a first numerology (M) and to a second user equipment (22) having MIMO OFDM receiver (200) using a second service type having a second numerology (N), where said first numerology (M) and said second numerology (N) are different than each other, characterized by comprising following steps:- receiving at least a first input signal having n number of OFDM symbols to be transmitted to the first user equipment (21 ),- applying n number of inverse fast Fourier transform (IFFT) to the first input signal, adding a first virtual cyclic prefix (411 ) to each OFDM sample and generating first OFDM symbols (410) for the first service;- applying a first fast Fourier transform (FFT) having larger FFT size than n and m to first OFDM symbols;- receiving (410) at least a second input signal having m number OFDM samples to be transmitted to the second user equipment (22),- applying m number of inverse fast Fourier transform (IFFT) to the second input signal, adding a second virtual cyclic prefix (421 ) to each OFDM sample and generating second OFDM symbols (420) for the second service; where first cyclic prefix and second cyclic prefix are different than each other; and first cyclic prefix and second cyclic prefix are lower in size than the largest cyclic prefix in a predetermined numerology table,- applying the first fast Fourier transform (FFT) to second OFDM symbols (420);- multiplexing (420) first OFDM symbols (410) and second OFDM symbols (420) depending on number of transmitting antennas (190);- applying Inverse Fast Fourier Transform (IFFT) to multiplexed first OFDM symbols (410), second OFDM symbols (420), adding an encapsulating prefix (310) and generating encapsulating OFDM symbols (300) for each transmitting antenna (190) where encapsulating cyclic prefix is the largest in size in said predetermined numerology table;- transmitting encapsulating OFDM symbols (300) symbols through transmitting antennas (190).

2. The method according to claim 1 , characterized by comprising the step of:- reducing cyclic prefixes by at least first ratio that is recorded on a memory means.

3. A method realized by a MIMO OFDM receiver (200) of a user equipment using a first service type for receiving data from a MIMO OFDM transmitter (100) of a base station, characterized by comprising steps of:- receiving encapsulating OFDM symbols;- removing (300) an encapsulating cyclic prefix (310) from said encapsulating OFDM symbols and acquiring first OFDM symbols (410) where encapsulating prefix (310) is the largest in size in said predetermined numerology table;- removing a first virtual cyclic prefix (411 ) from OFDM symbols where first cyclic prefix is lower in size than the largest cyclic prefix in said predetermined numerology table;- applying fast Fourier transform (FFT) and acquiring a first input signal.

4. The method according to claim 3, characterized by comprising the step of:- reducing cyclic prefixes by at least first ratio that is recorded on a memory means.

5. A MIMO OFDM transmitter (100) of a base station for transmitting data to at least a first user equipment (21 ) having MIMO OFDM receiver (200) using a first service type having a first numerology (M) and to a second user equipment (22) having MIMO OFDM receiver (200) using a second service type having a second numerology (N), where said first numerology (M) and said second numerology (N) are different than each other, characterized by- multiple receive antennas (110) configured to receive at least a first input signal having n number of OFDM symbols to be transmitted to the first user equipment (21 ) and at least a second input signal having m number of OFDM symbols to be transmitted to the second user equipment;- at least a S1 first IFFT module (131 ) configured to apply n number of inverse fast Fourier transform (IFFT) to the first input signal,- at least a S1 V-CP adder (141 ) configured to add a first virtual cyclic prefix (411 ) to the first input signal, and generating first OFDM symbols (410) for the first service;- at least a S2 first IFFT module (132) configured to apply m number of inverse fast Fourier transform (IFFT) to the second input signal,- at least a S2 V-CP adder (142) configured to add a second virtual cyclic prefix (421 ) to the second input signal, and generating second OFDM symbols (420) for the second service; where first cyclic prefix and second cyclic prefix are different than each other; and first cyclic prefix and second cyclic prefix are lower in size than the largest cyclic prefix in a predetermined numerology table,- at least a S1 FFT module (151 ) (241 ) configured to apply a first fast Fourier transform (FFT) to first OFDM symbols;- at (410) least a S2 FFT module (152) (242) configured to apply the first fast Fourier transform (FFT) to second OFDM symbols (420);- a (420) precoding unit (160) configured to multiplex first OFDM symbols (410) and second OFDM symbols; (420)- at least an encapsulating IFFT module (171 ) provided for each transmitting antenna (190) configured to apply Inverse Fast Fourier Transform (IFFT) to multiplexed first OFDM symbols (410) and second OFDM symbols (420);- at least an E-CP adder provided for each transmitting antenna (190) and configured to add an encapsulating prefix (310) to multiplexed first OFDM symbols (410) and second OFDM symbols (420) and generating a encapsulating OFDM symbols for each transmitting antenna where encapsulating cyclic prefix is the largest in size in said predetermined numerology table;- multiple transmitting antenna (190) configured to transmit encapsulating OFDM symbols (300).

6. A MIMO OFDM receiver (200) of a user equipment using a first service type for receiving data from a MIMO OFDM transmitter (100) of a base station, characterized by comprising- equipment receive antennas (1 10) configured to receive first encapsulating OFDM symbols;- at (300) least an E-CP remover (221 ) configured to remove an encapsulating cyclic prefix from said encapsulating OFDM symbols and acquire OFDM symbols (410) where encapsulating prefix (310) is the largest in size in said predetermined numerology table;- at least a S1 V-CP remover (231 ) configured to remove a first virtual cyclic prefix (411 ) from OFDM symbols where first cyclic prefix is lower in size than the largest cyclic prefix in said predetermined numerology table;- at least an equipment S1 FFT module (151 ) (241 ) configured to apply fast Fourier transform (FFT) and acquire a first input signal.

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