CN110138536B

CN110138536B - Method and device for sending physical downlink control channel and storage medium

Info

Publication number: CN110138536B
Application number: CN201910500397.3A
Authority: CN
Inventors: 姚坤
Original assignee: Realme Mobile Telecommunications Shenzhen Co Ltd
Current assignee: Realme Mobile Telecommunications Shenzhen Co Ltd
Priority date: 2019-06-11
Filing date: 2019-06-11
Publication date: 2022-02-08
Anticipated expiration: 2039-06-11
Also published as: CN110138536A

Abstract

In the application, under the condition that the quality of a downlink channel is abnormal, the minimum aggregation level is still used for scheduling transmission resources, the transmission resources are prevented from being transferred to a larger aggregation level to be scheduled, the transmission resources used for transmitting a Physical Downlink Control Channel (PDCCH) are reduced, so that the resources used for transmitting a Physical Downlink Shared Channel (PDSCH) are increased, and the throughput rate of transmission service data can be improved; in addition, the raised transmission power is used for sending the PDCCH on the scheduled transmission resource, so that the anti-interference capability of transmitting the PDCCH caused by the quality deterioration of a downlink channel is improved, and the transmission reliability of the PDCCH can be improved.

Description

Method and device for sending physical downlink control channel and storage medium

Technical Field

The present invention relates to the field of wireless communications, and in particular, to a method, an apparatus, and a storage medium for transmitting a physical downlink control channel.

Background

In a 3GPP (third generation partnership project long term evolution) protocol, an evolved node B (eNodeB) transmits service data to User Equipment (UE) through a PDSCH (physical downlink shared channel), and a plurality of UEs in an attached state in a cell can receive the service data on the Physical Downlink Shared Channel (PDSCH) in a shared manner. In order to ensure that the UE can correctly receive and decode the traffic data carried in the PDSCH, other signals such as a Physical Downlink Control Channel (PDCCH), a Synchronization Signal (SS), and a Reference Signal (RS) are transmitted in the currently scheduled subframe. When the channel quality of a downlink channel is poor, the eNodeB allocates more transmission resources to other signals such as the PDCCH, the SS, and the RS, however, the number of scheduled downlink transmission resources is fixed, and accordingly, the number of transmission resources allocated to the PDSCH is reduced, and for the UE in the cell, the throughput rate of transmitting service data is reduced, so how to improve the throughput rate of transmitting service data is an urgent problem to be solved at present.

Disclosure of Invention

Embodiments of the present invention provide a sending method, an apparatus, and a storage medium for a physical downlink control channel, which, when the quality of a downlink channel is degraded, still use the minimum number of transmission resources to send a PDCCH, and simultaneously improve the transmission power of the PDCCH, and improve the reliability of PDCCH transmission, so that the occupation of the transmission resources by the PDCCH can be reduced, more pairs of transmission resources are allocated to a PDSCH in a resource block, and the throughput rate of user data on the PDSCH is improved.

In a first aspect, the present application provides a method for sending a physical downlink control channel, including:

when the channel quality of a downlink channel is abnormal, the network equipment schedules transmission resources according to a minimum aggregation level, wherein the minimum aggregation level represents an aggregation level with the minimum transmission resources in a plurality of aggregation levels supported by the PDCCH; the network equipment transmits PDCCH on the scheduled transmission resource with a first transmission power; and the second transmission power is the transmission power adopted by the PDCCH when the channel quality of the downlink channel is normal, and the first transmission power is greater than the second transmission power.

In a second aspect, the present application provides an apparatus for sending a physical downlink control channel, including:

the processing unit is used for scheduling transmission resources according to the minimum aggregation level when the channel quality of the downlink channel is abnormal; the minimum aggregation level is the aggregation level with the least transmission resources in the multiple aggregation levels supported by the PDCCH;

a transceiving unit, configured to the network device send a PDCCH with the first transmit power on a scheduled transmission resource; and the second transmission power is the transmission power of the PDCCH when the channel quality of the downlink channel is normal, and the first transmission power is greater than the second transmission power.

On the other hand, an embodiment of the present invention provides a sending apparatus for a physical downlink control channel, where the sending apparatus is used for a function of a network device behavior in the foregoing method. The functions can be realized by hardware, and the functions can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the above-described functions.

In one possible design, the network device includes a processor and a transmitter in the structure, and the processor is configured to support the network device to perform the corresponding functions in the above method. The transmitter is used for supporting communication between the network device and the terminal device and transmitting information or instructions related to the method to the terminal device. The network device may also include a memory, coupled to the processor, that retains program instructions and data necessary for the base station.

A further aspect of the present application provides a computer storage medium comprising instructions which, when executed on a computer, cause the computer to perform the method as set forth in any one of the various possible implementations of the first aspect to the first aspect.

A further aspect of the present application provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method according to any of the various possible embodiments of the first aspect to the first aspect.

By implementing the embodiment of the application, when the channel quality of the downlink channel is deteriorated, the second transmission power is increased according to a preset power increase rule to obtain the first transmission power, the transmission resource is scheduled according to the minimum aggregation level, and the PDCCH is transmitted on the scheduled transmission resource by using the first transmission power. Therefore, when the channel quality of the downlink channel is deteriorated, the transmission resources are still scheduled by using the minimum aggregation level, the transmission resources are prevented from being scheduled by using a larger aggregation level, and the transmission resources used for transmitting the PDCCH are reduced, so that the resources used for transmitting the PDSCH are increased, and the throughput rate of transmission service data can be improved; in addition, the raised transmission power is used for sending the PDCCH on the scheduled transmission resource, so that the anti-interference capability of transmitting the PDCCH caused by the quality deterioration of a downlink channel is improved, and the transmission reliability of the PDCCH can be improved.

Drawings

Fig. 1 is a schematic structural diagram of a communication system according to an embodiment of the present invention;

fig. 2 is a flowchart illustrating a method for transmitting a physical downlink control channel according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an apparatus according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of another apparatus provided in the embodiment of the present invention.

Detailed Description

Fig. 1 is a schematic diagram of an architecture of a communication system according to an embodiment of the present invention, where the communication system includes a network device and at least one terminal device. Fig. 1 shows that network device 100 has terminal device 100 and terminal device 102 camped in a cell of network device 100. network device 100 and terminal device 101 are in communication with terminal device 102. The communication system may be a global system for mobile communication (GSM), a Code Division Multiple Access (CDMA) system, a Wideband Code Division Multiple Access (WCDMA) system, a Worldwide Interoperability for Microwave Access (WiMAX) system, a Long Term Evolution (LTE) system, a 5G communication system (e.g., a new radio, NR) system, a communication system in which a plurality of communication technologies are merged (e.g., a communication system in which an LTE technology and an NR technology are merged), or a communication system in which a subsequent evolution is performed, forms and numbers of base stations and terminal devices shown in fig. 1 are only for example and do not constitute a limitation of the embodiments of the present invention.

The terminal equipment in the application is equipment with a wireless communication function, can be deployed on land and comprises an indoor or outdoor, a handheld, a wearable or a vehicle-mounted terminal; can also be deployed on the water surface (such as a ship and the like); and may also be deployed in the air (e.g., airplanes, balloons, satellites, etc.). The terminal device may be a mobile phone (mobile phone), a tablet computer (Pad), a computer with a wireless transceiving function, a Virtual Reality (VR) terminal device, an Augmented Reality (AR) terminal device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote medical (remote medical), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety (transportation safety), a wireless terminal in smart city (smart city), a wireless terminal in home (smart home), and the like. The terminal device may also be a handheld device having wireless communication capabilities, a vehicle mounted device, a wearable device, a computing device or other processing device connected to a wireless modem, or the like. The terminal devices in different networks may be called different names, for example: a terminal device, an access terminal, a subscriber unit, a subscriber station, a mobile station, a remote terminal, a mobile device, a user terminal, a wireless communication device, a user agent or user equipment, a cellular telephone, a cordless telephone, a Session Initiation Protocol (SIP) telephone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a terminal device in a 5G network or a future evolution network, etc.

The network device in this application may also be referred to as a base station device, and is a device deployed in a radio access network to provide a wireless communication function, including but not limited to: a base station (e.g., BTS (base transceiver station), a node B (NodeB, NB), an evolved node B (eNB or eNodeB), a transmission node or a transmission reception point (TRP or TP) or a next generation node B (gNB) in the NR system, a base station or a network device in a future communication network), a relay station, an access point, a vehicle-mounted device, a wearable device, a wireless fidelity (Wi-Fi) station, a wireless backhaul node, a small station, a micro station, and so on.

In the LTE communication system, a length of a radio frame (radio frame) is 10ms, each subframe includes 10 subframes (subframes), each subframe includes 2 slots (slots), and Orthogonal Frequency Division Multiple Access (OFDMA) symbols included in each slot are distinguished according to different cyclic prefix types, where the OFDMA symbols are hereinafter referred to as symbols. In the case that the cyclic prefix is a normal cyclic prefix, each slot includes 7 symbols; in the case where the cyclic prefix is an extended cyclic prefix, 6 symbols are included in each slot. The information included in the subframe includes a Physical Downlink Shared Channel (PDSCH), a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator Channel (PCFICF), a physical hybrid automatic repeat request Channel (PHICH), a Reference Signal (RS), and a Synchronization Signal (SS). The PDSCH is a physical channel carrier carrying traffic data and traffic types, and multiple users in an attached state in a cell can share the PDSCH. The PDCCH includes scheduling information of transmission resources of the PDSCH, and the UE can receive traffic data in the PDSCH only after correctly decoding the PDCCH. According to the specification of the 3rd generation partnership project (3 GPP) protocol, the PDCCH typically occupies the first few symbols in the time domain, and the number of symbols occupied by the PDCCH is controlled by the PCFICH. For example: in a frequency division multiplexing-long term evolution (FDD-LTE) protocol, the number of symbols occupied by the PDCCH is shown in table 1:

TABLE 1

The CCE is a unit of a transmission resource for transmitting the PDCCH, wherein 4 consecutive unoccupied Resource Elements (REs) form one Resource Element Group (REG), 9 REGs form one channel control factor (CCE), the network device configures different aggregation levels for the PDCCH according to channel qualities of different downlink channels, and the aggregation level (aggregation layer) indicates the number of CCEs scheduled for the PDCCH. For one subframe, the LTE protocol supports 4 CCE aggregation levels: 1. 2, 4 and 8. According to the specification of 3GPP protocol, 1 CCE is scheduled by the network side to transmit PDCCH under very good wireless channel condition; the network side schedules 2 CCEs to transmit PDCCH under the normal wireless channel condition; under the condition of poor wireless channel condition, the network side calls 4 CCEs under the robust configuration to transmit the PDCCH; in case of very bad wireless channel conditions, the network side invokes 8 CCEs under the most robust configuration to transmit PDCCH. The network side improves the robustness and reliability of the PDCCH transmission under the condition of poor channel quality by scheduling more transmission resources, namely, the worse the downlink channel quality is, the more the number of the transmission resources scheduled for the PDCCH by the network side is.

For example: when the bandwidth of a downlink channel is 10MHz and 1 symbol is occupied by a PDCCH in a time domain, a control region in a scheduled downlink transmission resource contains 600(12 × 50RB) resource elements in total, where 200 reference signal resource elements +16 physical PCFICH resource elements +84 physical hybrid retransmission indicator channels are 300 resource elements; the total available resource elements of the PDCCH under 3 symbols are 1800-.

According to the above analysis, in the current scheme for scheduling transmission resources of a PDCCH, the worse the channel quality of a downlink channel is, the more the number of transmission resources scheduled for the PDCCH is, and correspondingly, the fewer the number of transmission resources available for the PDSCH in a subframe is, which may affect the throughput rate of UEs in an attached state in a cell for receiving service data carried on the PDSCH, and especially when the number of UEs attached in the cell is too large, the faster the throughput rate of each UE for receiving service data decreases.

In order to solve the above-mentioned technical problem, the present application provides the following technical solutions:

referring to fig. 2, a schematic flow chart of a method for sending a physical downlink control channel according to an embodiment of the present invention is shown, where in the embodiment of the present invention, the method includes:

s201, when the channel quality of the downlink channel is abnormal, the network equipment schedules transmission resources according to the minimum aggregation level.

The downlink channel is a channel for the network device to send data to the terminal device, and the quality parameter value of the downlink channel is used for evaluating the channel quality of the downlink channel. The method for monitoring the state of the downlink channel by the network equipment comprises the following steps:

the network device measures an uplink reference signal sent by the terminal device, for example: the network device measures Signal quality of an uplink Sounding Reference Signal (SRS), where the Signal quality of the uplink SRS may include: the method includes the steps that one or more of Reference Signal Receiving Power (RSRP), Reference Signal Receiving Quality (RSRQ), Received Signal Strength Indication (RSSI) and signal to interference noise ratio (SINR) are selected, the channel quality of an uplink channel is judged to be abnormal or normal by comparing a measured value with a threshold value, the uplink channel and a downlink channel have the characteristic of reciprocity, and the channel quality of the uplink channel is regarded as the channel quality of the downlink channel.

For example: when the RSRQ of the uplink channel is smaller than the threshold value, determining that the channel quality of the uplink channel is abnormal, the channel quality of the corresponding downlink channel is abnormal, when the network equipment configures the TPC command, configuring the bit of the TPC command to be all 1, and when the terminal equipment analyzes that the bit of the TPC command is all 1, indicating that the channel quality of the uplink channel is abnormal, and increasing the uplink transmitting power; when the RSRQ of the uplink channel is greater than or equal to the threshold, determining that the channel quality of the uplink channel is normal, when the network device configures the TPC command, configuring the bit of the TPC command to all 0 s, and when the terminal device receives the TPC command, determining that the channel quality of the uplink channel is normal without increasing the uplink transmission power.

The network device configures a transmission mode according to the channel quality of the uplink channel, for example: a Transmission Mode (TM) is configured in Downlink Control Information (DCI), and different TMs correspond to different channel qualities. For example: the LTE communication system supports 9 TM as follows:

1, TM 1: the single antenna port transmission is mainly applied to the occasions of single antenna transmission.

TM 2: open loop transmit diversity does not need to feed back Precoding Matrix Indicator (PMI), is suitable for the conditions of complex cell edge channels and large interference, and is sometimes used for the conditions of high speed, and diversity can provide diversity gain.

TM 3: the open-loop spatial multiplexing is adopted, the PMI does not need to be fed back, and the method is suitable for the high-speed movement of the UE.

TM 4: closed-loop spatial multiplexing requires PMI feedback, is suitable for occasions with good channel conditions, and is used for providing high-data-rate transmission.

TM 5: multi-user multiple-input multiple-output (MU-MIMO) transmission mode (downlink multi-user MIMO): mainly to increase the capacity of the cell.

TM 6: closed loop transmit diversity, closed loop Rank1 precoded transmission: the PMI needs to be fed back, mainly suitable for the cell edge case.

TM 7: single-stream beamforming (beamforming) mode of Port 5: mainly at the cell edge, which can effectively combat interference.

TM 8: the dual-stream beamforming mode may be used for cell edges as well as for other scenarios.

TM 9: the transmission mode 9 is a newly added mode in long term evolution-advanced (LTE-a), and can support transmission up to 8 layers, mainly for improving the data transmission rate.

When the transmission mode is the preset transmission mode, the network equipment determines that the channel quality of the downlink channel is abnormal. For example: when the transmission mode is TM2, it is determined that the transmission power of the PDCCH needs to be raised.

In an LTE communication system, a terminal device measures and reports a Channel Quality Indication (CQI), evaluates channel quality of a downlink channel according to a measurement result (e.g., SINR), determines a block error rate (BLER) that can be obtained under the channel quality of the downlink channel, and reports a corresponding CQI to a network device according to a restriction that the BLER is less than 10%. The modulation scheme determines the modulation order, and the modulation end indicates the number of bits transmitted per symbol. A modulation order corresponding to Quadrature Phase Shift Keying (QPSK) is 2, a modulation order corresponding to 16quadrature amplitude modulation (16 QAM) is 4, and a modulation order corresponding to 64QAM is 6. The code rate is the ratio of the number of information bits in the transport block to the total number of physical channel bits, i.e.:

the code rate is the number of information bits/the total number of physical channels bits in the transport block is the number of information bits/(total number of symbols of physical channels modulation order) is the efficiency/modulation order.

Therefore, different values of the CQI determine the difference between the downlink modulation mode and the transport block size. The larger the CQI is, the higher the modulation and coding scheme adopted is, the higher the efficiency is, the larger the corresponding transport block is, and the higher the downlink peak throughput is provided. The larger the CQI is, the better the quality of the downlink channel is, whereas the smaller the CQI is, the worse the quality of the downlink channel is.

The network device compares the CQI reported by the terminal device with a threshold value to determine whether the quality of the downlink channel is abnormal or normal, for example: the network equipment receives the CQI (channel quality indicator) reported by the terminal equipment, wherein the CQI is greater than a threshold value 8, and the channel quality of a downlink channel is determined to be normal; another example is: and the network receives that the CQI reported by the terminal equipment is 7, the CQI is less than a threshold value 8, and the channel quality of the downlink channel is determined to be abnormal.

In this embodiment, when the network device monitors that the channel quality of the downlink channel is abnormal, the network device schedules the transmission resource according to the minimum aggregation level, the multiple aggregation levels supported by the network device, and the minimum aggregation level is an aggregation level indicating the minimum number of the transmission resources among the multiple aggregation levels supported by the network device.

For example: the network device supports 4 aggregation levels of 1 CCE, 2 CCEs, 4 CCEs, and 8 CCEs, and the minimum aggregation level is 1.

The network device schedules transmission resources according to the minimum aggregation level, and the scheduling method comprises the following steps:

and the network equipment determines the downlink transmission resources scheduled on the current subframe, and schedules the transmission resources for transmitting the PDCCH in the downlink transmission resources according to the minimum aggregation level.

The network device may schedule the downlink transmission resource based on a dynamic scheduling method or a semi-static scheduling method, where a cycle of the dynamic scheduling method is smaller than a cycle of the semi-static scheduling method, for example: the period of dynamic scheduling is 1ms, and all service types are supported; semi-static scheduling: there is no standard period defined in the protocol, some vendors are 20ms, and the type of service supported is typically real-time service, such as VoIP. The downlink transmission resource is a resource used for transmitting downlink data, and the downlink data includes control information carried in a PDCCH or service data carried in a PDSCH. The network device schedules transmission resources for transmitting the PDCCH in the resources available in the downlink transmission resources according to the minimum aggregation level, and the method for the network device to schedule the transmission resources for transmitting the PDCCH may be: based on frequency domain preference or time domain preference.

S202, the network equipment transmits the PDCCH with first transmission power on the scheduled transmission resources.

Specifically, the first transmit power indicates that a quality parameter value of the downlink channel is smaller than a quality parameter threshold, and the first transmit power is greater than the second transmit power. And comparing the quality parameter value of the downlink channel with a quality parameter threshold, judging whether the channel quality is good or not according to the comparison result, and sending the PDCCH by the network equipment by using the second transmitting power under the condition of good channel quality. The network device transmits the PDCCH using the first transmission power when the downlink channel quality is abnormal. The network device schedules transmission resources of the PDCCH in resource blocks allocated to downlink transmission according to the minimum aggregation level, and the scheduling manner is not limited in this application, for example: the minimum aggregation level is 1, available REs are determined in downlink transmission resources corresponding to the current subframe, 1 CCE is scheduled in a time domain first mode, 1 CCE consists of 9 REGs, and each REG consists of 4 continuous available REs; another example is: and the minimum aggregation level is 2, determining available REs in downlink transmission resources corresponding to the current subframe, and scheduling 2 CCEs in the available REs in a frequency domain first mode. The network device allocates subcarriers of transmission resources scheduled to the PDCCH, and adjusts the transmission power of each subcarrier so that the PDCCH is transmitted at a first transmission power.

The method for determining the first transmission power of the PDCCH may include the following steps:

a. the second transmission power is transmission power adopted by the PDCCH when the quality of the downlink channel is normal, the second transmission power is a default value pre-stored or pre-configured by the network device, the first transmission power is greater than the second transmission power, and the worse the quality of the downlink channel is, the greater the first transmission power is.

Optionally, the quality of the downlink channel is represented by a CQI, and the quality of the downlink channel is normal when the CQI is greater than or equal to a threshold; otherwise, the quality of the downlink channel is abnormal. And under the condition that the quality of the downlink channel is abnormal, the worse the quality of the downlink channel is, the larger the first transmission power is, and the first transmission power is increased progressively according to a preset step value every time the CQI is reduced by one unit.

For example: as shown in expression 2, the first transmit power is equal to 1mW, the threshold value of the CQI is 8, and the preset step value is 0.5 mW.

CQI	First transmission power
		7	1.5mW
6	2.0mW
		5	2.5mW
4	3.0mW
		3	3.5mW
2	4.0mW
		1	4.5mW

TABLE 2

b. The transmission power adopted by the PDCCH in the current subframe is related to one or more of the transmission power of the PDSCH in the previous subframe, the bandwidth corresponding to the current subframe, the minimum aggregation level and the TPC command.

For example: and the transmission power of the PDSCH in the subframe above the first transmission power of the PDCCH of the current subframe is taken as a reference, and the first transmission power is obtained by increasing preset power on the reference.

Another example is: and carrying out base-10 logarithmic operation on the bandwidth corresponding to the current subframe to obtain a value, and multiplying the value by a constant larger than 1 to obtain the first transmission power of the PDCCH of the current subframe.

Another example is: and multiplying the transmission power of the PDSCH in the last subframe by the minimum aggregation level to obtain the first transmission power adopted by the PDCCH in the current subframe.

Another example is: when the TPC command indicates the terminal equipment to increase the uplink transmission power, the transmission power of the PDSCH of the previous subframe is taken as a reference, and the preset power is increased on the reference to obtain the first transmission power.

Another example is: the first transmission power of the PDCCH in the current subframe is represented by the following formula:

Power(PDCCH，i)＝Max{Power(PDSCH，i-1)，10lg(Bandwith，i)+Power_o_PDCCH(i)}*Min{CCE(i)}+f(i)；

wherein Power (PDCCH, i) represents the first transmission Power of PDCCH in the ith subframe, Max represents the maximum value, Power (PDSCH, i) represents the transmission Power of PDSCH in the (i-1) th subframe, Bandwith represents the bandwidth, (Bandwith, i) represents the bandwidth corresponding to the current subframe, represented by the number of RBs, Power _ o _ PDCCH (i) represents the transmission Power of PDCCH in the first subframe in the radio frame where the current subframe is located, min represents the minimum value, cce (i) represents various aggregation levels of transmission PDCCHs supported by the ith subframe, and f (i) is a constant related to TPC command. When the TPC command indicates the terminal equipment to increase the uplink transmission power, the network equipment can perform power lifting, namely, the PDCCH is transmitted at the first transmission power; when the TPC command indicates that the terminal device keeps the current uplink transmission power unchanged, the network device does not perform power up, that is, the PDCCH is still transmitted using the first transmission power.

In a possible implementation manner, when the channel quality of the downlink channel is abnormal, before the network device schedules the transmission resource according to the minimum aggregation level, the method further includes:

and when the throughput rate of the service data is smaller than the throughput rate threshold value, the network equipment sends the system information carrying the minimum aggregation level to the terminal equipment.

The throughput rate is an average rate of successfully transmitting data through a communication channel (a communication channel) or a node in a unit time, and is generally a bit per second (bps) unit. Before the network equipment sends the PDCCH to the terminal equipment, the network equipment sends system information to the terminal equipment, wherein the system information carries a minimum aggregation level, and the minimum aggregation level represents the number of CCEs used by the PDCCH to be sent. The terminal device may send feedback information to the network device according to the decoding condition of the service data, for example: when the terminal equipment successfully decodes the service data in the PDSCH, the terminal equipment returns an ACK to the network equipment; when the service data in the PDSCH is not successfully decoded, the terminal device returns a NACK to the network device. The network device can count the throughput rate of the initially transmitted service data in unit time according to the feedback information of the terminal device. The network device prestores or is preconfigured with a throughput rate threshold, and when the measured throughput rate is smaller than the throughput rate threshold, the network device sends system information carrying the minimum aggregation level to the terminal device to indicate that the terminal device receives the PDCCH and decodes the PDCCH by using the CCE corresponding to the minimum aggregation level no matter what channel quality is, and demodulates the PDSCH according to the decoding result of the PDCCH.

In one possible implementation, the network device instructs the terminal device to increase the threshold of the BLER, and if the threshold of the BLER is slightly increased, the network device may use a smaller aggregation level to schedule transmission resources for transmitting the PDCCH relative to the BLER before the threshold is increased, thereby reducing the signaling overhead of the PDCCH and increasing the transmission resources available for the PDSCH.

S203, the terminal device detects the PDCCH.

Different PDCCHs may be mapped to CCEs of different aggregation levels, when identifying a PDCCH, a parameter of a starting position index of the CCE is needed in addition to the parameter of the aggregation level, dynamic scheduling of downlink resources or uplink resources is performed in network equipment, and both the aggregation level and the starting position index of the CCE are allocated by the network equipment.

In one possible implementation, the terminal device may detect the PDCCH using a blind detection method:

in the downlink subframe, the terminal equipment cannot determine the aggregation level of the PDCCH and the starting position index of the CCE in advance, and for the terminal equipment, the position of the PDCCH is acquired by blind detection each time. The aggregation levels of the PDCCH may be divided into 1, 2, 4 and 8 according to the description in the LTE protocol.

For different search spaces (search spaces), the allowed aggregation levels are different, and the Number of PDCCH candidates is also limited, as specified in table 3 below.

TABLE 3

Wherein, for UE-specific search space (UE-specific search space), the terminal device can use 4 aggregation levels of 1, 2, 4, 8, while in common search space (common search space), the anti-interference and blind detection processing time are considered comprehensively, and only 4 and 8 are used

These 2 aggregation levels. The aggregation level is 8 at most, and the total number of CCEs occupied by PDCCH may be large, for example: the total number of CCEs occupied by the PDCCH is 88, and in a control region of 88 CCEs, there are many possible positions of the PDCCH, which are referred to as a set of PDCCH candidates. In order to reduce the time for blind detection of the terminal device, the number of candidate location sets is also limited, as shown in table 3 above, in the common search space, PDCCH with aggregation level of 8, the number of candidate location sets is only 2.

In another possible implementation, the terminal device obtains the number of CCEs used by the PDCCH according to the minimum aggregation level carried in the system information sent by the network device, and when obtaining the number of CCEs, the terminal device avoids the problem of excessive times caused by blind detection of the PDCCH, and reduces the time for decoding the PDCCH.

By implementing the embodiment of the application, under the condition that the quality of the downlink channel is abnormal, power is raised according to the preset power raising to obtain the first transmission power, the transmission resource is scheduled according to the minimum aggregation level, and the PDCCH is transmitted on the scheduled transmission resource by using the first transmission power. Therefore, under the condition that the quality of the downlink channel is abnormal, the minimum aggregation level is still used for scheduling transmission resources, the transmission resources are prevented from being transferred to a larger aggregation level to schedule the transmission resources, and the transmission resources used for transmitting the PDCCH are reduced, so that the resources used for transmitting the PDSCH are increased, and the throughput rate of transmission service data can be improved; in addition, the raised transmission power is used for sending the PDCCH on the scheduled transmission resource, so that the anti-interference capability of transmitting the PDCCH caused by the quality deterioration of a downlink channel is improved, and the transmission reliability of the PDCCH can be improved.

The method according to the embodiment of the present invention is explained in detail above, and a schematic structural diagram of an apparatus according to the embodiment of the present invention is provided below, which is hereinafter referred to as an apparatus 3, where the apparatus 3 includes a processing unit 301 and a transceiving unit 302, and the apparatus 3 is configured to execute a behavior function of a network device according to the embodiment of the method above.

A processing unit 301, configured to schedule, by the network device, a transmission resource according to the minimum aggregation level when the channel quality of the downlink channel is abnormal; the minimum aggregation level represents the aggregation level with the least transmission resources in a plurality of aggregation levels supported by a Physical Downlink Control Channel (PDCCH); for example: the processing unit 301 is configured to execute S201 in fig. 2, and specifically refer to the description of S201, which is described herein in detail.

A transceiving unit 302, configured to transmit a PDCCH on a scheduled transmission resource with a first transmit power; and the second transmission power is the transmission power adopted by the PDCCH when the channel quality of the downlink channel is normal, and the first transmission power is greater than the second transmission power. For example: the transceiver unit 302 is configured to execute S202 in fig. 2, and reference may be specifically made to the description of S202, which is not described herein again.

In a possible implementation, the transceiver unit 320 is further configured to: and sending the system information carrying the minimum aggregation level to the terminal equipment under the condition that the throughput rate of the service data is smaller than a throughput rate threshold value.

In a possible implementation manner, the PDCCH carries a transmission mode, and when the transmission mode is a preset transmission mode, the channel quality of the downlink channel is abnormal;

the PDCCH carries a Transmission Power Control (TPC) command, and when the transmission power command indicates that the uplink transmission power is increased, the channel quality of the downlink channel is abnormal; or

And under the condition that the CQI (channel quality indicator) reported by the terminal equipment is smaller than a threshold value, the channel quality of the downlink channel is abnormal.

In a possible implementation, the processing unit 301 is further configured to:

when the channel quality of the downlink channel is normal, scheduling transmission resources according to the minimum aggregation level;

the transceiving unit 302 is further configured to transmit the PDCCH on the scheduled transmission resource with the second transmit power.

In a possible implementation, the processing unit 301 is configured to schedule transmission resources according to a minimum aggregation level, and includes:

determining downlink transmission resources scheduled on a current subframe;

and scheduling transmission resources for transmitting the PDCCH in the downlink transmission resources according to the minimum aggregation level.

In one possible implementation, the first transmit power of the PDCCH in the current subframe is related to the transmit power of the PDSCH in the previous subframe, the bandwidth corresponding to the current subframe, the minimum aggregation level, and the TPC command.

In one possible embodiment, the first transmission power of the PDCCH in the current subframe is represented by the following formula:

wherein Power (PDCCH, i) represents the first transmission Power of the PDCCH in the ith subframe, Max represents the maximum value, Power (PDSCH, i) represents the transmission Power of the PDSCH in the (i-1) th subframe, Bandwith represents the bandwidth and is represented by the number of RBs; power _ o _ PDCCH (i) indicates the transmission Power of the PDCCH in the first subframe in the radio frame where the current subframe is located, min indicates the minimum value, cce (i) indicates the multiple aggregation levels supported by the ith subframe for transmitting the PDCCH, and f (i) is a constant related to the TPC command.

The above device embodiments only list logic functions between modules, and please refer to their corresponding method embodiments for specific execution processes and beneficial effects.

The device 3 may also be a field-programmable gate array (FPGA), an application-specific integrated chip, a system on chip (SoC), a Central Processing Unit (CPU), a Network Processor (NP), a digital signal processing circuit, a Micro Controller Unit (MCU), or a Programmable Logic Device (PLD) or other integrated chips.

The embodiment of the present invention and the embodiment of the method in fig. 2 are based on the same concept, and the technical effects brought by the embodiment of the present invention are also the same, and the specific process can refer to the description of the embodiment of the method in fig. 2, and will not be described herein again.

Fig. 4 is a schematic structural diagram of an apparatus according to an embodiment of the present invention, which is hereinafter referred to as an apparatus 4, where the apparatus 4 may be integrated in the foregoing network device, as shown in fig. 4, and the apparatus includes: memory 402, processor 401, and transceiver 403.

The memory 402 may be a separate physical unit, and may be connected to the processor 401 and the transceiver 403 via a bus. The memory 402, processor 401, transceiver 403 may also be integrated, implemented in hardware, etc.

The memory 402 is used for storing a program implementing the above method embodiment, or various modules of the apparatus embodiment, which is called by the processor 401 to perform the operations of the above method embodiment.

Alternatively, when part or all of the reference signal processing method of the above embodiments is implemented by software, the apparatus may also include only a processor. The memory for storing the program is located outside the device and the processor is connected to the memory by means of circuits/wires for reading and executing the program stored in the memory.

The processor may be a Central Processing Unit (CPU), a Network Processor (NP), or a combination of a CPU and an NP.

The processor may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a Programmable Logic Device (PLD), or a combination thereof. The PLD may be a Complex Programmable Logic Device (CPLD), a field-programmable gate array (FPGA), a General Array Logic (GAL), or any combination thereof.

The memory may include volatile memory (volatile memory), such as random-access memory (RAM); the memory may also include a non-volatile memory (non-volatile memory), such as a flash memory (flash memory), a Hard Disk Drive (HDD) or a solid-state drive (SSD); the memory may also comprise a combination of memories of the kind described above.

In the above embodiments, the sending module or the transmitter performs the sending steps of the above various method embodiments, the receiving module or the receiver performs the receiving steps of the above various method embodiments, and other steps are performed by other modules or processors. The transmitting module and the receiving module may constitute a transceiver module, and the receiver and the transmitter may constitute a transceiver.

The embodiment of the present application further provides a computer storage medium, which stores a computer program, where the computer program is used to execute the sending method of the physical downlink control channel provided in the foregoing embodiment.

The embodiment of the present application further provides a computer program product containing instructions, which when run on a computer, causes the computer to execute the method for sending a physical downlink control channel provided in the foregoing embodiment.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Claims

1. A method for transmitting a Physical Downlink Control Channel (PDCCH), comprising:

under the condition that the throughput rate of the service data is smaller than the throughput rate threshold value, the network equipment sends system information carrying the minimum aggregation level to the terminal equipment;

when the channel quality of the downlink channel is abnormal, the network equipment schedules transmission resources according to the minimum aggregation level; the minimum aggregation level represents the aggregation level with the least transmission resources in a plurality of aggregation levels supported by a Physical Downlink Control Channel (PDCCH);

the network equipment transmits a PDCCH on a scheduled transmission resource with a first transmission power; and the second transmission power is the transmission power adopted by the PDCCH when the channel quality of the downlink channel is normal, and the first transmission power is greater than the second transmission power.

2. The method of claim 1,

the PDCCH carries a transmission mode, and when the transmission mode is a preset transmission mode, the channel quality of the downlink channel is abnormal;

the PDCCH carries a Transmission Power Control (TPC) command, and when the transmission power control command indicates that the uplink transmission power is increased, the channel quality of the downlink channel is abnormal; or

3. The method of claim 2, further comprising:

when the channel quality of the downlink channel is normal, the network equipment schedules transmission resources according to the minimum aggregation level;

the network device transmits the PDCCH with the second transmission power on scheduled transmission resources.

4. The method of claim 3, wherein the network device schedules transmission resources according to a minimum aggregation level, comprising:

downlink transmission resources scheduled on the current subframe of the network equipment;

and the network equipment schedules the transmission resources for transmitting the PDCCH in the downlink transmission resources according to the minimum aggregation level.

5. The method of claim 1, wherein a first transmission power of the PDCCH in a current subframe is related to a transmission power of a Physical Downlink Shared Channel (PDSCH) in a previous subframe, a bandwidth corresponding to the current subframe, a minimum aggregation level and a TPC command.

6. The method of claim 5, wherein the first transmission power of the PDCCH in the current subframe is represented by the following formula:

7. A transmission apparatus of a physical downlink control channel, comprising:

a transceiving unit, configured to send, by a network device, a PDCCH on a scheduled transmission resource with a first transmit power; the second transmission power is the transmission power of the PDCCH when the channel quality of the downlink channel is normal, and the first transmission power is greater than the second transmission power;

the transceiving unit is further configured to send the system information carrying the minimum aggregation level to the terminal device when the throughput rate of the service data is smaller than the throughput rate threshold.

8. A transmission apparatus of a physical downlink control channel, comprising: at least one processor; and the number of the first and second groups,

a memory communicatively coupled to the at least one processor; wherein the content of the first and second substances,

the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the method of transmitting a physical downlink control channel according to any one of claims 1 to 6.

9. A computer storage medium comprising instructions that, when executed on a computer, cause the computer to perform the method of transmitting the physical downlink control channel according to any one of claims 1 to 6.