CN109792372B

CN109792372B - Method and device for transmitting signals

Info

Publication number: CN109792372B
Application number: CN201880003380.0A
Authority: CN
Inventors: 许华
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2017-01-27
Filing date: 2018-01-16
Publication date: 2020-06-16
Anticipated expiration: 2038-01-16
Also published as: WO2018137517A1; CN109792372A; TWI676380B; TW201828632A

Abstract

A method and apparatus for transmitting a signal are provided. In the method, all control channel elements of a physical downlink control channel candidate are allocated on one orthogonal frequency division multiplexing symbol and the physical downlink control channel is transmitted on the orthogonal frequency division multiplexing symbol using the physical downlink control channel candidate.

Description

Method and device for transmitting signals

This application claims priority to U.S. provisional application 62/451,256 filed on 27.01.2017, the entire contents of which are incorporated herein by reference.

Technical Field

The present invention relates to the field of communications, and in particular, to a method and apparatus for transmitting signals.

Background

In a Long Term Evolution (LTE) system, a Physical Downlink Control Channel (PDCCH) is transmitted on the first few Orthogonal Frequency Division Multiplexing (OFDM) symbols across the entire system bandwidth at the beginning of a subframe.

Compared to the LTE system, in a 5G New Radio (NR) system, especially at a higher frequency bandwidth (>6GHz), more spectrum can be used, and some new techniques such as Beam Forming (BF) are adopted. The use of BF will on the one hand increase the BF gain and reduce interference, and on the other hand the higher frequency wavelengths will reduce the size of the antenna array and make its implementation feasible. The PDCCH may also benefit from BF transmission to ensure its coverage and robustness.

In the 5G new wireless system, how to design PDCCH while efficiently supporting and using BF has become an urgent issue to be solved.

Disclosure of Invention

The present invention discloses a PDCCH design considering BF characteristics, which is novel and different from a PDCCH design in an LTE system.

In one embodiment, the technology herein includes providing a method of transmitting a signal. In this method, all Control Channel Elements (CCEs) of a PDCCH candidate are allocated on one OFDM symbol, and a PDCCH is transmitted on the OFDM symbol using the PDCCH candidate.

In one embodiment, the technology herein includes providing a method of transmitting a signal. In the method, a set of PDCCH candidates is configured for PDCCH, and the PDCCH is repeatedly transmitted on different OFDM symbols using the set of PDCCH candidates.

In one embodiment, the technology herein includes providing a method of transmitting a signal. In the method, a set of PDCCH candidates is configured for PDCCH, and the set of PDCCH candidates is spread over different OFDM symbols.

In one embodiment, the technology herein includes providing a method of transmitting a signal. In the method, PDCCH candidates allocated to the same OFDM symbol are used to transmit PDCCHs with different beams.

In one embodiment, the technology herein includes providing a method of allocating resources. In this method, all CCEs of one PDCCH candidate are allocated on the same OFDM symbol.

In one embodiment, the technology herein includes providing a method of allocating resources. In this method, all PDCCH candidates configured for one PDDCH are allocated on the same symbol.

In one embodiment, the technology herein includes providing a method of allocating resources. In this method, all PDCCH candidates configured for one PDCCH are scattered over different symbols.

Drawings

Fig. 1 shows a wireless communication system.

Fig. 2 shows a terminal.

Fig. 3 shows a network device.

Fig. 4 shows a PDCCH structure in LTE.

Fig. 5 shows an example of a PDCCH candidate.

Fig. 6 shows beam-link pairs in a 5G NR system.

Fig. 7 shows a diagram of PDCCH candidates transmitted with different beams on different OFDM symbols.

Fig. 8 shows a diagram of PDCCH candidates transmitted with different beams on the same OFDM symbol.

Fig. 9 shows a schematic diagram in which a set of PDCCH candidates is spread (split).

Fig. 10 shows another schematic diagram in which a set of PDCCH candidates are dispersed.

Fig. 11 shows a schematic diagram in which PDCCH candidates are reallocated.

Fig. 12 is a block diagram of an apparatus for transmitting a signal according to an embodiment of the present invention.

Fig. 13 is a block diagram of an apparatus according to an embodiment of the present invention.

Detailed Description

Fig. 1 shows a wireless communication system according to an embodiment of the invention. The wireless communication system shown in fig. 1 may operate in a high frequency band, which includes, but is not limited to, a Long Term Evolution (LTE) system, a fifth generation (5G) system for future evolution, a New Radio (NR) system, and a machine to machine (M2M) system. The wireless communication system shown in fig. 1 is merely an example of the technical solution of the embodiment of the present invention, and is not intended to limit the scope of the embodiment of the present invention. It will be appreciated by those skilled in the art that as network architectures evolve and new business scenarios emerge, the solutions presented herein are equally applicable to solving similar technical problems arising therein.

As shown in fig. 1, a wireless communication system 100 may include one or more network devices 101, one or more terminals 103, and a core network 111.

Network device 101 may be a base station that may communicate with one or more terminals and may also communicate with base stations that have terminal capabilities. In a 5G NR system, the base station may be a gNB (G-Node B). Terminals 103 may be distributed in the wireless communication system 100. The terminal 103 may be fixed or mobile. In some embodiments, terminal 103 may be a mobile device, mobile station, mobile unit, M2M terminal, wireless unit, remote unit, user agent, mobile client, or the like. The network device 101 may communicate with the terminal 103 under the control of a controller (not shown in the figure). In some embodiments, the controller may be part of the core network 111 or integrated into the network device 101. The network devices 101 may also communicate with each other directly or indirectly through a backhaul interface 107, such as an X2 interface. The network device 101 may be used to transmit control information or user data to the core network 111 through a backhaul interface 109, such as an S1 interface. A terminal 103 may be located within the coverage of one or more cells 105.

Fig. 2 shows a terminal 200. The terminal 200 may include one or more terminal processors 201, memory 202, a communication interface 203, a bus 204, a receiver 205, a transmitter 206, a coupler 207, an antenna 208, a user interface 209, input/output devices (e.g., microphone, keypad, display, etc.), and the like. The processor 201, communication interface 203, receiver 205, and transmitter 206 may be connected by a bus 204 or otherwise. The terminal 200 can communicate with other communication devices such as network devices through the communication interface 203. Transmitter 206 may be used to transmit, e.g., perform signal modulation, on signals output from terminal processor 201. Input/output devices 210 may be used to enable interaction between terminal 200 and a user/external environment. A memory 202 is connected to the terminal processor 201 for storing various software programs and/or instructions. Terminal processor 201 may be configured to read and execute computer readable instructions, such as stored in memory 202.

Fig. 3 shows a network device 300. Network device 300 may be a gbb. Network device 300 may include one or more network device processors 301, memory 302, communication interface 303, transmitter 305, receiver 306. The above components may be connected by a bus 304 or other means. As shown in fig. 3, the network device 300 may also include a coupler 307 and an antenna 308 connected to the coupler. The communication interface 303 may be used for the network device 300 to communicate with other communication devices, such as terminal devices or other network devices. The transmitter 305 may be used to transmit, e.g., perform signal modulation, a signal output from the network device processor 301. The network device processor 301 may be used for radio channel management, communication link establishment, and cell handover control for users within a control area, etc. The network device processor 301 is also operable to read and execute computer readable instructions, such as computer readable instructions stored in a memory 302 coupled to the network device processor 301.

Term(s) for

Physical Downlink Control Channel (PDCCH): the PDCCH is a set of physical resource elements carrying downlink control information, which includes transport format, resource allocation, uplink scheduling grant, power control, uplink retransmission information, and the like.

In a Long Term Evolution (LTE) system, as shown in fig. 4, a PDCCH is transmitted on one or more sets of resources called Control Channel Elements (CCEs), and each CCE is further divided into a plurality of Resource Element Groups (REGs). REGs from different PDCCHs are interleaved and spread throughout a Downlink (DL) control region to obtain diversity gain.

PDCCH candidate (candidate): a PDCCH candidate is a set of time-frequency Resource Elements (REs) that may be used to transmit the PDCCH. The set of PDCCH candidates includes at least one candidate that may be configured for one PDCCH.

CCE aggregation level (AL; also known as aggregation level or aggregation level): CCE AL denotes the number of consecutive CCEs occupied by the PDCCH. Different CCE AL may accommodate different performance requirements of the PDCCH. For each CCE AL, there may be multiple PDCCH candidates.

When scheduling the UE, the eNB will select the correct CCE AL and candidates and transmit the PDCCH using the set of time-frequency resources. On the UE side, the UE will Blind Decode (BD) these PDCCH candidates until finding its PDCCH. As shown in fig. 5, different PDCCH candidates for different CCE ALs may overlap in time-frequency. As can be seen from fig. 5, CCE AL ═ 1 indicates that one PDCCH candidate occupies one CCE, and similarly, CCE AL ═ 3 indicates that one PDCCH candidate occupies three CCEs.

Beam Link Pair (BLP) and application thereof

As described above, BF can be adopted in the 5G NR system, and both the system side and the user equipment side can use transmission BF and reception BF to increase BF gain. As shown in fig. 6, different transmission beams and reception beams may form different BLPs and the reception performance of each BLP may be different.

From a transmission (transmit) perspective, if analog BF techniques are used, the entire OFDM symbol may be transmitted on the same beam. Thus, to ensure that the PDCCH can be transmitted to the UE on the correct beam, the system may transmit the PDCCH to the UE using different beams at different times. This operation on the system side is transparent to the UE, since the handover may occur dynamically and the system side may not send any signal to the UE to inform the UE of such a change before transmitting the PDCCH. In view of this problem, the PDCCH candidates and the search space may be designed to cope with the problem, and the BLP handover can be improved and the robustness of PDCCH transmission can be improved.

Allocation of entire PDCCH candidates

As an embodiment, in a method of transmitting a signal, all CCEs of one PDCCH candidate are allocated to one OFDM symbol, and a PDDCH is transmitted on the OFDM symbol using the PDCCH candidate. This process can be better understood from fig. 7 and 8. In fig. 7 and 8, each block on an OFDM symbol represents a candidate. In this way, the UE may first search for its PDCCH candidates directly on the first symbol, if not decoded correctly, the UE may start searching for its PDCCH candidates on the second symbol, and so on. This may therefore facilitate blind decoding of the UE.

It should be noted that, for convenience of explanation, an OFDM symbol is used as an example herein, but the technical solution of the embodiment of the present invention may also be applied to other symbols such as a single-carrier frequency-division multiple access (SC-FDMA) symbol and other symbols and carriers for carrying a PDCCH that may occur in the future.

The scheme proposed herein differs from the LTE scheme shown in fig. 4 in that in the PDCCH candidate allocation scheme proposed herein, an entire PDCCH candidate (and corresponding CCE) is allocated to the same OFDM symbol. In other words, the resource allocation is performed in units of candidates, not in units of REGs.

Whereas in the LTE system shown in fig. 4, REGs for the same PDCCH candidate are allocated across different OFDM symbols in the control region, as can be seen from fig. 4, each square in a symbol represents one REG. The reason for this difference between the allocation scheme of the present invention and that of LTE is the motivation and the difference in the technology used. In LTE, BF techniques are not used for the PDCCH, and therefore, the PDCCH is divided into multiple CCEs and further into multiple groups of REGs, and the REGs of different PDCCHs are interleaved across different OFDM symbols to obtain diversity gain in time and frequency. In contrast, in the 5G NR system, BF techniques are used and different OFDM symbols are used for transmission on different transmission beams.

As described above, a set of PDCCH candidates (possibly including one or more PDCCH candidates) may be configured for one PDCCH. Based on this, how PDCCH candidates for one PDDCH are allocated on an OFDM symbol and how the PDCCH is transmitted will be described below. For example, in a method of transmitting a signal, a set of PDCCH candidates configured for one PDCCH may be allocated on one OFDM symbol, and the PDCCH may be transmitted with different beams on the OFDM symbol using the set of PDCCH candidates. The PDCCH may be transmitted repeatedly on different OFDM symbols. Alternatively, a set of PDCCH candidates configured for one PDCCH may be spread (split, also referred to as "split", "divide", etc.) over different OFDM symbols, that is, over two or more OFDM symbols, and the PDCCH may be transmitted on the different OFDM symbols using the same or different beams. These solutions will be described in detail below.

Example 1

In this embodiment, we will discuss how PDCCH candidates are used to transmit PDCCH on different OFDM symbols.

As shown in fig. 7, a plurality of PDCCH candidates are allocated on different OFDM symbols, and the PDCCH may be transmitted with beams in different directions, respectively, using the PDCCH candidates. PDCCH candidates for PDCCH #1 and PDCCH #2 are allocated on different OFDM symbols, i.e., OFDM symbol #1 and OFDM symbol #2, respectively, and PDCCH on each OFDM symbol is transmitted using different beams. This may facilitate transmission of PDCCH on different transmission beams, and thus may reduce the risk of beam mismatch and improve the robustness of PDCCH transmission.

PDCCH candidates (in fig. 7, only one candidate is shown on one OFDM symbol for each PDCCH) may be repeatedly allocated on different OFDM symbols, and thus PDCCHs using these PDCCH candidates may be repeatedly transmitted on different OFDM symbols with different beams. Referring to fig. 7, PDCCH candidates (together with corresponding CCEs) allocated on OFDM symbol #1 are repeatedly allocated on OFDM symbol # 2.

For one PDCCH, PDCCH candidates configured for the PDCCH may be allocated on one OFDM symbol.

Alternatively, PDCCH candidates configured for one PDCCH may be scattered over different symbols, and the PDCCH may be transmitted in different beams on the different symbols using the PDCCH candidates. That is, different PDCCH candidates (along with corresponding CCEs) may be allocated on different OFDM symbols, and the PDCCH may be transmitted on different OFDM symbols using these PDCCH candidates. This will be described in detail in example 3 below.

Different/same PDCCH candidates (along with all corresponding CCEs) may be allocated on different OFDM symbols and PDCCH may be transmitted on different beams using these PDCCH candidates, thus exploiting BF gain while avoiding beam mismatch between the system and the UE.

Alternatively, the PDCCH using PDCCH candidates allocated to different OFDM symbols may be transmitted using the same beam. For example, if the load on one OFDM symbol is very small, or there are few or no candidates allocated on that OFDM symbol, different OFDM symbols may be transmitted using the same beam. That is, whether to use the same or different beams for different symbols is not strictly limited, but may be flexibly configured according to, for example, the load of the symbols.

Example 2

In this embodiment, we will discuss how PDCCH is transmitted using PDCCH candidates on the same symbol.

It is assumed that the system side or the gNB in a 5G NR system (which is similar to the eNB in LTE, and here can also be other access devices) has multiple antenna array transceiver panels, i.e. assuming digital BF is used, different transmit/receive beams can be formed on the same OFDM symbol. In this case, PDCCHs using different PDCCH candidates configured for them may be transmitted on the same OFDM symbol and from different transmission beams to increase beam coverage and obtain energy gain, which is particularly advantageous especially when the UE is moving.

As shown in FIG. 8, PDCCH #1 will be transmitted in different beams using PDCCH candidate #1-a and PDCCH candidate #1-b, which fall within the coverage of the different beams, respectively. The same applies to PDCCH # 2. PDCCH #2 will be transmitted in different beams using PDCCH candidate #2-a and PDCCH candidate #2-b, which fall within the coverage of the different beams, respectively.

Similar to embodiment 1, four PDCCH candidates on the OFDM symbol shown in fig. 8 may be repeatedly allocated to other OFDM symbols, and the PDCCH may be transmitted with a beam different from that of the OFDM symbol shown in fig. 8.

These embodiments may facilitate blind decoding by the UE if the UE does not receive information about the total number of OFDM symbols of the control region. The UE may first search for its PDCCH candidates directly on the first symbol, and if not successfully decoded, may start searching for its PDCCH candidates on the second symbol, and so on. The method according to embodiments of the present invention also reduces the decoding delay on the UE side, because the UE can start decoding the PDCCH candidates on the first symbol after receiving them without buffering the second and third OFDM symbols before starting the PDCCH decoding process.

However, such a repeated allocation approach as described above may increase the total number of PDCCH candidates, and thus increase the amount of blind decoding for the UE. In view of this, another embodiment is given below.

Example 3

To keep the overall blind decoding unchanged, the PDCCH candidates may also be separated and allocated on different OFDM symbols. For example, as shown in fig. 9, PDCCH candidates for different CCE ALs are evenly spread over different OFDM symbols. The PDCCH candidates allocated to each OFDM symbol may include PDCCH candidates of different CCE ALs.

Fig. 10 shows another possible way of dispersion. Unlike fig. 9, in fig. 10, PDCCH candidates are not evenly dispersed. PDCCH candidates for the same CCE AL may be allocated to different symbols or on the same symbol. For example, a PDCCH candidate with CCEAL ═ 4 is allocated on OFDM symbol # 2. Of course, these dispersion modes are merely exemplary, and the embodiments of the present invention are not limited thereto.

Such a PDCCH candidate allocation scheme provided in embodiment 3 may be semi-statically configured and transmitted to the UE through a higher layer signal. The configuration information may include the total number of PDCCH candidates allocated per OFDM symbol, the number of PDCCH candidates per CCE AL allocated per OFDM symbol, and may also be location information of PDCCH candidates per OFDM symbol. The configuration information may further include a total number of OFDM symbols to which PDCCH candidates of the UE may be allocated, which may be the same as or different from the total number of OFDM symbols of the control region. For example, if the total control region (or control resource set) has three OFDM symbols in the time domain, the configuration information of a certain UE may include only the first two OFDM symbols, i.e., the first OFDM symbol and the second OFDM symbol. In another example, the configuration information of the UE may include only the last two OFDM symbols, i.e., the second OFDM symbol and the third OFDM symbol of the three OFDM symbol control resource sets. The different number of PDCCH candidates allocated per OFDM symbol may be based on the coverage of the beam, the beam formed per OFDM symbol (e.g., other beam-related information such as the number of beams, the type of beam, and the location of the beam, which is not limited in this disclosure), and the load on each OFDM symbol. For example, if the gNB knows that the UE is within the coverage of a beam, the gNB may allocate most PDCCH candidates for the UE on the OFDM symbols transmitted on that beam. If the UE is in a coverage area where the two beams overlap, the gNB may allocate PDCCH candidates on OFDM symbols transmitted on the two beams, respectively.

Example 4

Alternatively, if the load on one OFDM symbol (i.e., the number of PDCCH candidates for all UEs transmitting on that OFDM symbol) is saturated (full) or nearly saturated (for which the gNB may determine based on Discontinuous Transmission (DTX) fed back from the UEs), the gNB may allocate PDCCH candidates to other OFDM symbols. Here, different OFDM symbols may be transmitted with the same or different beams, thus making resource allocation more flexible.

An example is shown in fig. 11. As shown in fig. 11, initially, five PDCCH candidates for PDCCH #1 and two PDCCH candidates for PDCCH #2 are allocated on OFDM symbol #1, and no candidates are allocated on OFDM symbol # 2. Here, the load of OFDM symbol #1 may be large, and in view of balance and transmission reliability, two PDCCH candidates for PDCCH #1 and one PDCCH candidate for PDCCH #2 may be shifted, for example, from OFDM symbol #1 to OFDM symbol #2, with the shifted result shown in the lower half of fig. 11. Alternatively, all PDCCH candidates for PDCCH #2 may be shifted onto OFDM symbol #2, while PDCCH candidates for PDCCH #1 remain on OFDM symbol # 1.

The technical solutions described in the different embodiments above can be combined with and replaced by each other without conflict. For example, the technical solution of embodiment 4 may be combined with any one of embodiments 1 to 3.

The technical scheme provided by the invention can support BF of the PDCCH, and is convenient for transmitting the PDCCH on different transmission beams, so that the risk of beam mismatch is reduced, and the robustness of PDCCH transmission is improved. The technical scheme can be used for more effectively distributing the control resources for the control channel on different OFDM symbols and reducing the overall blocking rate. Such flexible resource allocation of PDCCH candidates may reduce the BD of the UE.

In addition, in order to reduce BD and blocking rate, the number of PDCCH candidates allocated for each UE may be semi-statically configured. For example, if a UE is at the cell edge and has difficulty receiving PDCCH, the gNB may allocate more PDCCH candidates for the UE; because the UE is assigned more PDCCH candidates, the UE may have more opportunities to receive correctly. Conversely, if the UE is in the center of the cell and has a good signal to interference plus noise ratio (SINR), the total amount of PDCCH candidates for the UE may be reduced, thereby leaving more resources for other UEs and lowering the BD of the UE for power saving. Based on the above principle, the PDCCH candidates for each CCE AL may also be adjusted in a semi-static manner for each UE.

Device

According to the embodiment of the invention, the invention also provides a device for transmitting the signal. In particular implementations, the apparatus may use the PDCCH design described above and may be configured to perform the method of transmitting signals described above.

Fig. 12 is a block diagram showing the apparatus for transmitting a signal. As shown in fig. 12, the apparatus 40 may include an allocation unit 42 and a transmission unit 44. The device 40 may be arranged on the gbb side and communicate with the UE. The allocation unit 42 may be a processor integrated with resource configuration functionality. The transmission unit 44 may be a transmitter, a transceiver, an antenna, a wireless transmission device, and other devices equipped with transmission functions.

In transmitting a signal, allocation unit 42 may be configured to allocate all CCEs of a PDCCH candidate onto one OFDM symbol, and transmission unit 44 may be configured to transmit a PDCCH using PDCCH candidates on that OFDM symbol.

In one embodiment, transmission unit 44 may transmit the PDCCH with different beams on the same OFDM symbol using PDCCH candidates for the PDCCH. In another embodiment, transmission unit 44 may transmit the PDCCH with the same or different beams on different OFDM symbols using PDCCH candidates.

The details of the above method embodiment are also applicable to this device embodiment and will not be described here again.

Certain aspects of embodiments of the invention described herein may be implemented as a computer program product or software which may include, for example, a computer-readable storage medium or a non-transitory machine-readable medium having stored thereon instructions which may be used to program a computer system (or other electronic device) or processor to perform a method of allocating resources or a method of transmitting signals according to embodiments of the invention. A non-transitory machine-readable medium may include any storage mechanism for storing information in a form (e.g., software, processing application, etc.) readable by a machine (e.g., a computer). Forms of non-volatile machine-readable media may include, for example, but are not limited to, magnetic storage media, optical storage media (e.g., CD-ROM), magneto-optical storage media, Read Only Memory (ROM), Random Access Memory (RAM), erasable programmable memory, flash memory, and the like.

Based on this, fig. 13 shows a device 50, in which device 50 a processor 52 is provided, and one or more interfaces 56 connected with processor 52 via a bus 54.

Processor 52 may be configured to read and execute computer-readable instructions. In one embodiment, the processor 52 may mainly include a controller, an arithmetic unit, and a register, and the hardware architecture of the processor 52 may be an Application Specific Integrated Circuit (ASIC) architecture, a microprocessor with no internal interlocked pipeline (MIPS) architecture, an advanced Reduced Instruction Set (RISC) machine (ARM) architecture, or a Network Processor (NP) architecture.

The interface 56 may be used to input data to be processed to the processor 52 and/or to output a processing result of the processor 52 to the outside. The interface 56 may be connected to one or more peripheral devices such as a display (e.g., a Liquid Crystal Display (LCD)), a camera, a radio frequency module, etc.

In conjunction with the technical solution provided by the embodiment of the present invention, the processor 52 may call a program related to the method for transmitting a signal according to the embodiment of the present invention from the memory, and execute instructions included in the program to implement relevant operations such as resource configuration and signal transmission. The interface 56 may be used to output the results of the resource allocation so that the transceiver can transmit signals based on the allocated resources.

With the technical solution described herein, a new PDCCH design is provided that can adapt to the requirements of a 5G NR system. The PDCCH design can support BF of the PDCCH, avoid beam mismatching of the PDCCH, support flexible resource allocation of PDCCH candidates, and reduce BD of each UE and the overall blocking rate.

Although the present invention has been described with reference to specific features and embodiments thereof, it will be understood that the above embodiments are merely examples and the scope of the present invention is not limited thereto. Various alterations, modifications, additions, and improvements may be made to the embodiments of the invention. The above-described functions may be separated or combined in different programs, or described using different terminology in different embodiments of the present invention.

Claims

1. A method for transmitting signals is applied to a 5G new wireless system and comprises the following steps:

allocating all control channel elements of a physical downlink control channel candidate to the same orthogonal frequency division multiplexing symbol, and transmitting a physical downlink control channel on the orthogonal frequency division multiplexing symbol by using the physical downlink control channel candidate;

the physical downlink control channel candidates allocated to the same orthogonal frequency division multiplexing symbol include physical downlink control channel candidates with different control channel unit polymerization degrees, and the physical downlink control channel candidates are a group of time-frequency resource elements used for transmitting the physical downlink control channel.

2. The method according to claim 1, wherein a set of physical downlink control channel candidates is configured for the physical downlink control channel, the method further comprising:

repeatedly transmitting the physical downlink control channel on different orthogonal frequency division multiplexing symbols using the set of physical downlink control channel candidates.

3. The method according to claim 1, wherein a set of physical downlink control channel candidates is configured for the physical downlink control channel, the method further comprising:

and dispersing the group of physical downlink control channel candidates to different orthogonal frequency division multiplexing symbols.

4. The method of claim 3, further comprising:

transmitting the physical downlink control channel with the same beam on the different orthogonal frequency division multiplexing symbols using the set of physical downlink control channel candidates.

5. The method of claim 3, further comprising:

transmitting the physical downlink control channel with different beams on the different orthogonal frequency division multiplexing symbols using the set of physical downlink control channel candidates.

6. The method according to any of claims 3-5, wherein the set of physical downlink control channel candidates is scattered over the different orthogonal frequency division multiplexing symbols based on at least one of: beam coverage, a beam formed on each orthogonal frequency division multiplexing symbol, a load on each orthogonal frequency division multiplexing symbol.

7. The method according to any of claims 3-5, wherein the configuration of spreading the set of physical downlink control channel candidates over the different orthogonal frequency division multiplexing symbols is done via a higher layer signal.

8. The method of claim 7, wherein the configuration comprises at least one of: the total number of the physical downlink control channel candidates on each orthogonal frequency division multiplexing symbol, the number of the physical downlink control channel candidates of each control channel element polymerization degree allocated on each orthogonal frequency division multiplexing symbol, the position of the physical downlink control channel candidates on each orthogonal frequency division multiplexing symbol, and all orthogonal frequency division multiplexing symbol information allocated with the physical downlink control channel candidates.

9. The method of claim 1 or 2, further comprising:

transmitting the physical downlink control channel with different beams on different orthogonal frequency division multiplexing symbols using physical downlink control channel candidates.

10. The method of claim 1 or 2, further comprising:

transmitting the physical downlink control channel with different beams on the same orthogonal frequency division multiplexing symbol using physical downlink control channel candidates.

11. The method according to claim 1, wherein the total number of physical downlink control channel candidates allocated to a user equipment and/or the number of physical downlink control channel candidates per degree of control channel element aggregation allocated to the user equipment is configured via higher layer signals.

12. A method for transmitting signals is applied to a 5G new wireless system and comprises the following steps:

allocating all control channel elements of a physical downlink control channel candidate onto the same orthogonal frequency division multiplexing symbol and transmitting a physical downlink control channel on the orthogonal frequency division multiplexing symbol with a beam different from beams used for other orthogonal frequency division multiplexing symbols using the physical downlink control channel candidate;

13. The method of claim 12, further comprising:

transmitting the physical downlink control channel with different beams on the same orthogonal frequency division multiplexing symbol using different physical downlink control channel candidates for the physical downlink control channel.

14. The method according to claim 12 or 13, wherein the physical downlink control channel candidates for the physical downlink control channel are allocated on the same orthogonal frequency division multiplexing symbol.

15. The method according to claim 12 or 13, wherein the physical downlink control channel candidates for the physical downlink control channel are allocated on different orthogonal frequency division multiplexing symbols.

16. An apparatus for transmitting a signal, comprising:

an allocation unit, configured to allocate all control channel elements of a physical downlink control channel candidate to a same orthogonal frequency division multiplexing symbol; and

a transmission unit, configured to transmit a physical downlink control channel on the ofdm symbol using the physical downlink control channel candidate;

17. The apparatus according to claim 16, wherein in transmitting the physical downlink control channel on the orthogonal frequency division multiplexing symbol using the physical downlink control channel candidate, the transmitting unit is further configured to:

transmitting the physical downlink control channel on the orthogonal frequency division multiplexing symbol with a beam different from beams used for other orthogonal frequency division multiplexing symbols using the physical downlink control channel candidates.

18. The apparatus according to claim 16 or 17, wherein the transmission unit is further configured to transmit the physical downlink control channel with different beams on the same orthogonal frequency division multiplexing symbol using different physical downlink control channel candidates for the physical downlink control channel.

19. The apparatus according to claim 16 or 17, wherein the transmission unit is further configured to repeatedly transmit the physical downlink control channel on two orthogonal frequency division multiplexing symbols using a set of physical downlink control channel candidates.

20. An apparatus for transmitting a signal, comprising a processor and a memory connected to the processor and for storing instructions that, when executed by the processor, cause the processor to perform the method of any of claims 1 to 11.

21. An apparatus for transmitting signals, comprising a processor and a memory connected to the processor and for storing program instructions which, when executed by the processor, cause the processor to carry out the method according to any one of claims 12 to 15.

22. A computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the method of any one of claims 1 to 11.

23. A computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the method of any one of claims 12 to 15.