CN109587819B

CN109587819B - Random access method and device, storage medium, user equipment and base station

Info

Publication number: CN109587819B
Application number: CN201710907294.XA
Authority: CN
Inventors: 汪绍飞; 周化雨; 贾亚男
Original assignee: Spreadtrum Communications Shanghai Co Ltd
Current assignee: Spreadtrum Communications Shanghai Co Ltd
Priority date: 2017-09-29
Filing date: 2017-09-29
Publication date: 2021-01-05
Anticipated expiration: 2037-09-29
Also published as: CN109587819A

Abstract

A random access method and device, storage medium, user equipment and base station are provided, the method comprises the following steps: when random access based on a competition mechanism is carried out, an uplink lead code is sent to a base station; determining a PDCCH through blind detection according to the uplink lead code; acquiring a TRS from a preset time-frequency resource in a time slot in which the PDCCH is positioned; compensating a PDSCH in a preset time slot according to the TRS and the time slot where the PDCCH is located; and acquiring RAR in the compensated PDSCH. The scheme of the invention can improve the success rate of the user equipment for acquiring the RAR.

Description

Random access method and device, storage medium, user equipment and base station

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a random access method and apparatus, a storage medium, a user equipment, and a base station.

Background

In the LTE system, a Cell Reference Signal (CRS) is an Always-On (Always-On) Signal, and a period of the CRS is 5 milliseconds, so that even in an idle state, a user equipment can adjust one or more of carrier time offset, carrier frequency offset, delay spread and doppler spread by using the CRS within a time range not exceeding 5 milliseconds, thereby ensuring that the user equipment can successfully receive downlink information such as broadcast messages/paging messages/random access in the idle state.

However, in the NR communication system, currently, 3GPP has not discussed the configuration of a time frequency Tracking Reference Signal (TRS) of a ue in an idle state, and only the TRS in a Radio Resource Control (RRC) connected state is configured, so that in the NR system, the absence of the Reference Signal enables the ue to perform fine carrier-to-time offset/carrier-to-frequency offset estimation and delay spread/doppler spread estimation, which affects the success rate of receiving a Random Access Response (RAR) by the ue in the idle state.

There is a need for a random access method configured with a TRS in an idle state for optimizing one or more of carrier time offset, carrier frequency offset, delay spread, and doppler spread.

Disclosure of Invention

The technical problem to be solved by the present invention is to provide a random access method and apparatus, a storage medium, a user equipment, and a base station, which can improve the success rate of acquiring RAR by the user equipment.

To solve the above technical problem, an embodiment of the present invention provides a random access method, including the following steps: when random access based on a competition mechanism is carried out, an uplink lead code is sent to a base station; determining a PDCCH through blind detection according to the uplink lead code; acquiring a TRS from a preset time-frequency resource in a time slot in which the PDCCH is positioned; compensating a PDSCH in a preset time slot according to the TRS and the time slot where the PDCCH is located; and acquiring RAR in the compensated PDSCH.

Optionally, the uplink preamble has an index, and the random access method further includes: determining an uplink lead code index carried by the RAR; and if the uplink lead code index carried by the RAR is consistent with the uplink lead code index, determining that the RAR is successfully received.

Optionally, determining, according to the uplink preamble, the PDCCH by blind detection includes: determining RA-RNTI according to the time-frequency resource for sending the uplink lead code; and determining the PDCCH scrambled by the RA-RNTI through blind detection according to the RA-RNTI.

Optionally, the acquiring the TRS by using a preset time-frequency resource in a time slot where the PDCCH is located includes: acquiring downlink control information in the PDCCH, wherein the downlink control information comprises TRS indication information which is used for indicating whether the TRS is sent in a time slot in which the PDCCH is located; and if the TRS indication information indicates that the TRS is sent in the time slot in which the PDCCH is positioned, acquiring the TRS from a preset time-frequency resource in the time slot in which the PDCCH is positioned.

Optionally, the preset time-frequency resource is a fixed time-frequency position in a time slot.

Optionally, according to the TRS and the time slot where the PDCCH is located, compensating for the PDSCH in the preset time slot includes: compensating the PDSCH in the time slot of the PDCCH according to the TRS; or compensating the PDSCH in the Nth time slot after the time slot where the PDCCH is located according to the TRS, wherein N is a positive integer.

Optionally, the TRS occupies at most one full slot.

Optionally, the slot includes 14 OFDM symbols.

To solve the above technical problem, an embodiment of the present invention provides a random access method, including the following steps: receiving an uplink lead code from user equipment when the user equipment performs random access based on a competition mechanism; configuring a PDCCH to be sent according to the uplink lead code, and configuring a TRS (time frequency resource) in a preset time slot in which the PDCCH is located; and sending a PDCCH to the user equipment, so that the user equipment compensates the PDSCH in a preset time slot according to the TRS and the time slot in which the PDCCH is positioned, and acquiring RAR in the compensated PDSCH.

Optionally, configuring the PDCCH to be sent according to the uplink preamble includes: configuring RA-RNTI according to the time-frequency resource of the uplink lead code; and transmitting the PDCCH scrambled by the RA-RNTI to the user equipment.

Optionally, configuring the TRS with a preset time-frequency resource in a time slot where the PDCCH is located includes: configuring downlink control information in the PDCCH, wherein the downlink control information comprises TRS indication information which is used for indicating whether the TRS is sent in a time slot in which the PDCCH is located; and if the TRS indication information indicates that the TRS is sent in the time slot of the PDCCH, configuring the TRS in a preset time-frequency resource in the time slot of the PDCCH.

To solve the foregoing technical problem, an embodiment of the present invention provides a random access apparatus, including: the uplink lead code sending module is suitable for sending the uplink lead code to the base station when random access based on a competition mechanism is carried out; the PDCCH determining module is suitable for determining the PDCCH through blind detection according to the uplink lead code; the TRS acquisition module is suitable for acquiring TRS from a preset time-frequency resource in a time slot where the PDCCH is located; the PDSCH compensation module is suitable for compensating the PDSCH in a preset time slot according to the TRS and the time slot where the PDCCH is located; and the RAR acquisition module is suitable for acquiring RAR in the compensated PDSCH.

Optionally, the uplink preamble has an index, and the random access apparatus further includes: an RAR uplink lead code index determining module, adapted to determine an uplink lead code index carried by the RAR; and the RAR reception success determining module is adapted to determine that the RAR reception is successful when the uplink preamble index carried by the RAR is consistent with the uplink preamble index.

Optionally, the PDCCH determining module includes: the RA-RNTI determining sub-module is suitable for determining RA-RNTI according to the uplink lead code; and the PDCCH determining submodule is suitable for determining the PDCCH scrambled by the RA-RNTI through blind detection according to the RA-RNTI.

Optionally, the TRS obtaining module includes: a downlink control information obtaining sub-module, adapted to obtain downlink control information in the PDCCH, where the downlink control information includes TRS indication information, and the TRS indication information is used to indicate whether to send the TRS in a time slot where the PDCCH is located; and the TRS acquisition sub-module is suitable for acquiring the TRS in a preset time-frequency resource in the time slot of the PDCCH when the TRS indication information indicates that the TRS is transmitted in the time slot of the PDCCH.

Optionally, the PDSCH compensating module includes: the first PDSCH compensation submodule is suitable for compensating the PDSCH in the time slot where the PDCCH is located according to the TRS; or a second PDSCH compensation submodule, adapted to compensate the PDSCH in an Nth time slot after the time slot in which the PDCCH is located according to the TRS, wherein N is a positive integer.

Optionally, the TRS occupies at most one full slot.

Optionally, the slot includes 14 OFDM symbols.

To solve the foregoing technical problem, an embodiment of the present invention provides a random access apparatus, including: an uplink lead code receiving module, adapted to receive an uplink lead code from a user equipment when the user equipment performs random access based on a contention mechanism; the PDCCH configuration module is suitable for configuring a PDCCH to be sent according to the uplink lead code, and the TRS is configured on a preset time-frequency resource in a time slot where the PDCCH is located; and the PDCCH sending module is used for sending a PDCCH to the user equipment so that the user equipment compensates the PDSCH in a preset time slot according to the TRS and the time slot where the PDCCH is located, and acquires RAR in the compensated PDSCH.

Optionally, the PDCCH configuring module includes: the RA-RNTI configuration sub-module is suitable for configuring RA-RNTI according to the time frequency resource of the uplink lead code; and the PDCCH sending sub-module is suitable for sending the PDCCH scrambled by the RA-RNTI to the user equipment.

Optionally, the PDCCH configuring module includes: a downlink control information configuration submodule, adapted to configure downlink control information in the PDCCH, where the downlink control information includes TRS indication information, and the TRS indication information is used to indicate whether to send the TRS in a time slot where the PDCCH is located; a TRS configuring sub-module, adapted to configure the TRS in a preset time-frequency resource in a time slot in which the PDCCH is located when the TRS indication information indicates that the TRS is transmitted in the time slot in which the PDCCH is located.

To solve the foregoing technical problems, embodiments of the present invention provide a storage medium having stored thereon computer instructions, which when executed perform the steps of the random access method described above.

In order to solve the foregoing technical problem, an embodiment of the present invention provides a user equipment, which includes a memory and a processor, where the memory stores computer instructions capable of being executed on the processor, and the processor executes the steps of the random access method when executing the computer instructions.

In order to solve the above technical problem, an embodiment of the present invention provides a base station, including a memory and a processor, where the memory stores computer instructions capable of being executed on the processor, and the base station is characterized in that the processor executes the computer instructions to perform the steps of the random access method.

Compared with the prior art, the technical scheme of the embodiment of the invention has the following beneficial effects:

in the embodiment of the invention, when random access based on a competition mechanism is carried out, an uplink lead code is sent to a base station; determining a PDCCH through blind detection according to the uplink lead code; acquiring a TRS from a preset time-frequency resource in a time slot in which the PDCCH is positioned; compensating a PDSCH in a preset time slot according to the TRS and the time slot where the PDCCH is located; and acquiring RAR in the compensated PDSCH. By adopting the scheme, when random access based on a competition mechanism is carried out, the PDCCH is determined through blind detection according to the uplink lead code, and the TRS is obtained from the preset time-frequency resource in the time slot where the PDCCH is located, so that the TRS is adopted to compensate the PDSCH containing the RAR, one or more of carrier time offset, carrier frequency offset, time delay expansion and Doppler expansion of the PDSCH are optimized, and the success rate of obtaining the RAR by the user equipment is improved.

Further, in the embodiment of the present invention, TRS indication information is set in downlink control information to explicitly indicate whether to send the TRS in a time slot in which the PDCCH is located, so that the user equipment can obtain the TRS in a preset time-frequency resource in the time slot in which the PDCCH is located in a targeted manner, thereby improving a success rate of obtaining the TRS by the user equipment, and when the TRS indication information does not indicate sending, the resource of the TRS indication information can be used for other applications, which is beneficial to improving a time-frequency resource utilization rate.

Further, in the embodiment of the present invention, the PDSCH in the nth time slot after the time slot in which the PDCCH is located may be compensated according to the TRS, and compared with the PDSCH in the time slot in which the PDCCH is compensated according to the TRS, because the TRS is analyzed in the time slot in which the PDCCH is located, after the PDSCH is received in the nth time slot, the PDSCH may be compensated without analyzing the TRS in the current time slot, which is beneficial to improving the timeliness of compensating the PDSCH.

Drawings

Fig. 1 is a data flow diagram of a random access method in the prior art;

fig. 2 is a flow chart of a random access method in an embodiment of the present invention;

FIG. 3 is a flowchart of one embodiment of step S22 of FIG. 2;

FIG. 4 is a flowchart of one embodiment of step S23 of FIG. 2;

FIG. 5 is a flowchart of one embodiment of step S24 of FIG. 2;

fig. 6 is a partial flow chart of another random access method in an embodiment of the present invention;

fig. 7 is a flowchart of a random access method according to another embodiment of the present invention;

FIG. 8 is a partial flow diagram of one embodiment of step S72 of FIG. 7;

FIG. 9 is a partial flow diagram of another embodiment of step S72 of FIG. 7;

fig. 10 is a schematic structural diagram of a random access apparatus according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of an embodiment of the PDCCH determining module 102 in fig. 10;

fig. 12 is a schematic structural diagram of an embodiment of the TRS acquisition module 103 of fig. 10;

fig. 13 is a schematic diagram of an embodiment of the PDSCH compensating module 104 of fig. 10;

fig. 14 is a schematic structural diagram of another random access apparatus according to an embodiment of the present invention;

fig. 15 is a schematic structural diagram of an embodiment of the PDCCH configuring module 142 in fig. 14.

Detailed Description

As described in the background art, in the LTE system, the user equipment in an idle state may adjust one or more of carrier time offset, carrier frequency offset, delay spread, and doppler spread by using the CRS, so as to ensure that the user equipment in the idle state can successfully receive downlink information such as broadcast message/paging message/random access.

Wherein the Carrier Time Offset (CFO) is used to represent a Time Offset of a Carrier on a channel; the Carrier Frequency Offset (CFO) is used to represent the Frequency Offset of the Carrier on the channel, which may cause sub-Carrier crosstalk.

Regarding the delay spread, the signal arriving at the receiving end is a composite signal of the signals passing through different paths and having time difference. The composite signal will exhibit a delay spread in the time domain relative to the original signal.

Doppler Spread (Doppler Spread) is used to describe channel frequency dispersion, often caused by relative motion between a base station and a user device or object motion in the channel.

However, in the NR system, at present, 3GPP only discusses the TRS in the RRC connected state, specifically, the TRS in the RRC connected state appears periodically in the time domain and is configured specifically for a specific user equipment, and specifically, a specific user equipment is configured by an Information Element (Information Element) of RRC signaling. Regarding the TRS configuration of the user equipment in the idle state, due to the lack of the reference signal, the user equipment performs fine carrier time offset/carrier frequency offset estimation and delay spread/doppler spread estimation, which affects the success rate of receiving the RAR by the idle user equipment.

Referring to fig. 1, fig. 1 is a data flow diagram of a random access method in the prior art. The random access method may be used for a contention based random access procedure, and may include steps S11 to S14, which are described below.

In step S11, the user equipment 11 sends an uplink Preamble (Preamble) to the base station 12.

Specifically, when the user equipment 11 in the idle state needs to perform Random Access based on the contention mechanism, it selects a Random Access CHannel (RACH) configuration in the Remaining Minimum System Information (Remaining Minimum System Information), and sends an uplink preamble to the base station 12.

In a specific implementation, in step S11, the message that the user equipment 11 sends the uplink preamble to the base station 12 is also referred to as MSG1 message.

In step S12, the user equipment 11 receives a random access response from the base station 12.

Specifically, in a specific time domain window after the uplink preamble is transmitted, the ue 11 monitors a Physical Downlink Control CHannel (PDCCH) scrambled by a Random Access Radio Network Temporary Identity (RA-RNTI), and performs PDCCH blind detection. After the PDCCH is successfully blind-detected, an Index (Index) of an uplink preamble in the RAR carried by a Physical Downlink Shared Channel (PDSCH) is obtained. When the index of the uplink preamble in the RAR matches the index of the uplink preamble sent by the user equipment 11 to the base station 12 in step S11, the RAR reception is considered to be successful.

In a specific implementation, in step S12, the message that the user equipment 11 receives the RAR from the base station 12 is also referred to as MSG2 message.

In step S13, the user equipment 11 transmits a Scheduled Transmission message to the base station 12.

Specifically, when the RAR is successfully received, the UE 11 reports its user name (UE ID) to the base station according to its connection state (idle state or RRC connection state), that is, performs scheduling transmission. Wherein the UE ID needs to be obtained from the core network by the user equipment 11 in the idle state in advance.

In a specific implementation, in step S13, the user equipment 11 sends a message of scheduling transmission to the base station 12, which is also referred to as MSG3 message.

In step S14, the user equipment 11 receives a Contention Resolution (Contention Resolution) message from the base station 12.

Specifically, the base station 12 will send a message to the user equipment 11 in a specific time window, and if the UE ID of the user equipment 11 in the received message is consistent with the UE ID carried by the user equipment 11 in the MSG3 sending message, the user equipment succeeds in the random access procedure.

In a specific implementation, in step S14, the message received by the user equipment 11 from the base station 12 is also referred to as MSG4 message.

In the random access method shown in fig. 1, due to lack of TRS transmission and reception, it is difficult for the user equipment 11 to perform fine carrier-to-time offset/carrier-to-frequency offset estimation and delay spread/doppler spread estimation, which affects the success rate of receiving the RAR/MSG4 by the idle user equipment.

The inventor of the present invention finds, through research, that in the prior art, the time-frequency tracking reference Signal TRS configuration of the user equipment in an idle state has not been discussed yet, so that, in an NR system, on one hand, a period of a Synchronization Signal cluster Set (SSB Set) is as minimum as 5 milliseconds and as maximum as 160 milliseconds, since there are no other normally-open reference signals in the NR, the user equipment can perform fine carrier-time offset/carrier-frequency offset estimation and delay spread/doppler spread estimation, and when the period of the Synchronization Signal block Set is large, the idle-state user equipment can be influenced to successfully receive a randomly-accessed RAR/MSG4 message. Wherein the MSG4 message is received for contention resolution in a random access procedure.

On the other hand, in NR, since a Synchronization Signal Block (SSB) may be simultaneously transmitted from multiple Transmission Reception Points (TRPs) in a Single Frequency broadcast Network (Single Frequency Network), and a RAR/MSG4 message received by a ue is transmitted from one of the TRPs, the estimation result by the SSB is a carrier time offset/carrier Frequency offset result of a composite beam, which is difficult to compensate for the carrier time offset/carrier Frequency offset of the ue receiving the RAR/MSG4 message.

Therefore, in the NR system, it is imperative that the idle ue configures a TRS for one or more of carrier time offset, carrier frequency offset, delay spread and doppler spread in receiving the RAR/MSG4 message.

In the embodiment of the invention, when random access based on a competition mechanism is carried out, an uplink lead code is sent to a base station; determining a PDCCH through blind detection according to the uplink lead code; acquiring a TRS from a preset time-frequency resource in a time slot in which the PDCCH is positioned; compensating a PDSCH in a preset time slot according to the TRS and the time slot where the PDCCH is located; and acquiring RAR in the compensated PDSCH. By adopting the scheme, when random access based on a competition mechanism is carried out, the PDCCH is determined through blind detection according to the uplink lead code, and the TRS is obtained from the preset time-frequency resource in the time slot where the PDCCH is located, so that the TRS is adopted to compensate the PDSCH containing the RAR, one or more of time offset, carrier frequency offset, time delay expansion and Doppler expansion of the PDSCH carrier are optimized, and the success rate of obtaining the RAR by the user equipment is improved.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

Referring to fig. 2, fig. 2 is a flowchart of a random access method in an embodiment of the present invention. The random access method may be used for a user equipment, and may include steps S21 to S25:

step S21: when random access based on a competition mechanism is carried out, an uplink lead code is sent to a base station;

step S22: determining a PDCCH through blind detection according to the uplink lead code;

step S23: acquiring a TRS from a preset time-frequency resource in a time slot in which the PDCCH is positioned;

step S24: compensating a PDSCH in a preset time slot according to the TRS and the time slot where the PDCCH is located;

step S25: and acquiring RAR in the compensated PDSCH.

In the specific implementation of step S21, when the ue in idle state needs to perform random access based on contention mechanism, it selects a RACH configuration in the remaining minimum system message, and sends an uplink preamble to the base station.

In a specific implementation of step S22, in a specific time domain window after the uplink preamble is sent, the ue monitors the PDCCH scrambled by the RA-RNTI, performs PDCCH blind detection, and determines the PDCCH through the blind detection.

Fig. 3 shows a specific embodiment of step S22 in fig. 2, and the step of determining the PDCCH by blind detection according to the uplink preamble may include steps S31 to S32, which are described below.

In step S31, an RA-RNTI is determined according to the time-frequency resource for transmitting the uplink preamble.

Specifically, the RA-RNTI is used to indicate a resource block used by the user equipment to transmit the uplink preamble, so that the RA-RNTI can be determined according to the time-frequency resource of the uplink preamble.

In step S32, the PDCCH scrambled by the RA-RNTI is determined by blind detection based on the RA-RNTI.

Specifically, the ue determines a starting position of a Control Channel Element (CCE), and intercepts a guessed length of Downlink Control Information (DCI) at the starting position of the CCE, and decodes the length, and if a Cyclic Redundancy Check (CRC) of decoded Information bits is the same as a CRC carried in the PDCCH, it determines that the Information bits carried by the current PDCH are the currently transmitted Downlink Control Information. The CRC includes various RNTIs, for example, RA-RNTI used in MSG 2.

With continued reference to fig. 2, in a specific implementation of step S23, a TRS is obtained from a preset time-frequency resource in a time slot where the PDCCH is located. Wherein the configuration of the TRS transmitted by the base station may be unique.

Specifically, the preset time-frequency resource may be a fixed time-frequency position in a time slot, so that the ue may accurately determine whether a TRS exists in the time slot according to the fixed time-frequency position in any time slot.

It should be noted that, in this embodiment of the present invention, the TRS may be configured to transmit on a single port, so that the RAR/MSG4 message received by the user equipment is transmitted from a determined single port, and thus the TRS may be used to perform carrier time offset/carrier frequency offset compensation on the RAR/MSG4 message.

Specifically, compared with the prior art that an SSB may be simultaneously transmitted from multiple ports (e.g. TRP) in the form of a single frequency broadcast network, resulting in that an RAR/MSG4 message received by a user equipment is transmitted from one of the ports, and therefore depending on that the estimation result of the SSB is the result of carrier time offset/carrier frequency offset of one composite beam, it is difficult to use the result in carrier time offset/carrier frequency offset compensation of the user equipment in receiving the RAR/MSG4 message, in the embodiment of the present invention, using a single port to transmit TRS helps to enable the user equipment to implement carrier time offset/carrier frequency offset compensation in receiving the RAR/MSG4 message.

Further, in a specific implementation manner of the embodiment of the present invention, the TRS may be configured to the user equipment in an implicit manner.

Specifically, the implicit mode is used to indicate that the time slot in which the PDCCH scrambled by the RA-RNTI is located is the default TRS, that is, the base station must transmit the TRS when transmitting the time slot scrambled by the RA-RNTI. Therefore, after the user equipment in an idle state successfully blindly detects the PDCCH scrambled by the RA-RNTI, the default received PDSCH where the RAR is located carries the TRS signal.

It should be noted that, if at this time, one connected ue and one idle ue have the same RA-RNTI, the connected ue may ignore the TRS of the timeslot and directly obtain the RAR information. For example, according to an information element of RRC signaling.

In another specific implementation manner of the embodiment of the present invention, the TRS may be explicitly configured to the ue.

Specifically, referring to fig. 4, fig. 4 is a flowchart of one specific implementation of step S23 in fig. 2. The step of acquiring the TRS according to the preset time-frequency resource in the time slot of the PDCCH may include steps S41 to S42, which are described below.

In step S41, downlink control information is acquired in the PDCCH, where the downlink control information includes TRS indication information for indicating whether to transmit the TRS in a time slot in which the PDCCH is located.

In a specific implementation, after the user equipment in an idle state successfully performs blind detection on the PDCCH scrambled by the RA-RNTI, a certain field of the DCI in the PDCCH may have TRS indication information, for example, 1 bit, indicating whether the TRS is transmitted in the time slot.

In step S42, if the TRS indication information indicates that the TRS is sent in the time slot where the PDCCH is located, the TRS is obtained from a preset time-frequency resource in the time slot where the PDCCH is located.

Specifically, the preset time-frequency resource may be a fixed time-frequency position in a time slot, so that the user equipment may accurately determine the TRS according to the fixed time-frequency position in the time slot where the PDCCH is located.

In the embodiment of the invention, TRS indication information is set in the downlink control information to explicitly indicate whether to send the TRS in the time slot of the PDCCH, so that the user equipment can obtain the TRS in the preset time-frequency resource in the time slot of the PDCCH in a targeted manner, the success rate of obtaining the TRS by the user equipment is improved, and when the TRS indication information is not indicated to be sent, the resource of the TRS indication information can be used for other applications, thereby being beneficial to improving the time-frequency resource utilization rate.

With continued reference to fig. 2, in a specific implementation of step S24, the TRS is adopted to compensate the PDSCH in a preset time slot according to the TRS and the time slot in which the PDCCH is located.

Referring to a specific embodiment of step S24 in fig. 2 shown in fig. 5, the step of compensating for the PDSCH in the preset time slot according to the TRS and the time slot in which the PDCCH is located may include step S51 or step S52, and each step is described below.

In step S51, the PDSCH in the time slot in which the PDCCH is located is compensated according to the TRS.

Specifically, the acquired TRS may be analyzed in a time slot where the PDCCH is located, and then the TRS is adopted to compensate the PDSCH.

In step S52, the PDSCH in the nth time slot after the time slot in which the PDCCH is located is compensated according to the TRS, where N is a positive integer.

Specifically, the TRS may be analyzed in a time slot where the PDCCH is located, so that after the PDSCH is received in the nth time slot, the TRS may be compensated without being analyzed in the current time slot.

In the step shown in step S52, compensating the PDSCH in the nth slot after the slot in which the PDCCH is located according to the TRS helps to improve timeliness of compensation for the PDSCH compared to the step shown in step S51.

It should be noted that, an existing conventional TRS compensation manner may be adopted to compensate for one or more of carrier time offset, carrier frequency offset, delay spread, and doppler spread related to the PDSCH, and in the embodiment of the present invention, a specific implementation manner of TRS compensation for the PDSCH is not limited.

Further, the TRS may occupy at most one full slot.

Specifically, the TRS occupies only the time domain resources in one time slot in the time domain, that is, the time slot in which the RAR is received by the user equipment, for example, at most one complete time slot or less than one complete time slot, and occupies a continuous bandwidth in the frequency domain.

Preferably, the slot may include 14 OFDM symbols.

Specifically, the slot is set to include 14 OFDM symbols, which helps to configure complete TRS information in one slot and better implement the effect of compensating PDSCH compared to other settings (e.g., the slot includes 7 OFDM symbols).

With continued reference to fig. 2, in a specific implementation of step S25, RAR is acquired in the compensated PDSCH.

Specifically, the RAR is acquired in the compensated PDSCH, which is more beneficial to improving the success rate of acquiring the RAR by the user equipment compared with the prior art in which the RAR is directly acquired in the uncompensated PDSCH.

In the embodiment of the invention, when random access based on a competition mechanism is carried out, a PDCCH is determined through blind detection according to an uplink lead code, and a TRS is obtained from a preset time-frequency resource in a time slot where the PDCCH is located, so that the TRS is adopted to compensate a PDSCH containing RAR, one or more of time offset, carrier frequency offset, time delay expansion and Doppler expansion of a PDSCH carrier are optimized, and the success rate of obtaining the RAR by user equipment is improved.

Referring to fig. 6, fig. 6 is a partial flowchart of another random access method in an embodiment of the present invention. The another random access method may be used for the user equipment, and may include steps S21 to S25 of the random access method shown in fig. 2, and may further include steps S61 to S62:

step S61: determining an uplink lead code index carried by the RAR;

step S62: and if the uplink lead code index carried by the RAR is consistent with the uplink lead code index, determining that the RAR is successfully received.

In the specific implementation of step S61, after the PDCCH is successfully blind-detected, the ue obtains the index of the uplink preamble in the RAR carried by the PDSCH.

In the specific implementation of step S62, since the uplink preamble sent by the ue to the base station also has an index, the index of the uplink preamble is compared with the index of the uplink preamble in the RAR carried by the obtained PDSCH, and if the two indexes are consistent, it is determined that the RAR is successfully received.

It is noted that, after determining that the RAR is successfully received, the random access method may further include a step in which the user equipment box base station transmits a scheduling transmission message (MSG3 message), and a step in which the user equipment receives a contention resolution message (MSG4 message) from the base station.

Specifically, when the RAR is successfully received, the UE may report the UE ID obtained from the core network in advance to the base station side through the MSG3 message, the base station may send the MSG4 message to the UE in a specific time window, and if the UE ID in the MSG4 message received by the UE is consistent with the UE ID carried in the MSG3 message sent by the UE, the UE succeeds in the random access procedure.

It should be noted that, although the random access methods shown in fig. 2 to fig. 6 are all described by taking the TRS acquisition in the process of receiving and sending the MSG2 message as an example, if the TRS is configured for time-frequency tracking in the contention resolution based contention access (MSG4) message, the random access method in the embodiment of the present invention is also applicable.

Referring to fig. 7, fig. 7 is a flowchart of another random access method in an embodiment of the present invention. The still another random access method may be used for a base station, and may include steps S71 to S73, each of which is described below.

In step S71, when the user equipment performs random access based on the contention mechanism, an uplink preamble is received from the user equipment.

In a specific implementation, more details regarding step S71 are described with reference to step S21 in fig. 2, and are not described herein again.

In step S72, the PDCCH to be transmitted is configured according to the uplink preamble, and the TRS is configured in a preset time-frequency resource in a time slot where the PDCCH is located.

Referring to fig. 8, fig. 8 is a partial flowchart of an embodiment of step S72 in fig. 7, and the step of configuring the PDCCH to be transmitted according to the uplink preamble may include steps S81 to S82, which are described below.

In step S81, according to the time-frequency resource of the uplink preamble, RA-RNTI is configured.

In step S82, the PDCCH scrambled by the RA-RNTI is transmitted to the user equipment.

For more details regarding steps S81 to S82, please refer to the description of steps S31 to S32 in fig. 3, which is not repeated herein.

Referring to fig. 9, fig. 9 is a partial flowchart of another embodiment of step S72 in fig. 7. The step of configuring the TRS with a preset time-frequency resource in a slot where the PDCCH is located may include steps S91 to S92, which are described below.

In step S91, downlink control information is configured in the PDCCH, where the downlink control information includes TRS indication information for indicating whether to transmit the TRS in a slot in which the PDCCH is located.

In step S92, if the TRS indication information indicates that there is a TRS to be transmitted in the time slot where the PDCCH is located, the TRS is configured on a preset time-frequency resource in the time slot where the PDCCH is located.

For more details about steps S91 to S92, please refer to the description of steps S41 to S42 in fig. 4, which is not repeated herein.

With reference to fig. 7, in step S73, a PDCCH is sent to the ue, so that the ue compensates a PDSCH in a preset time slot according to the TRS and the time slot where the PDCCH is located, and acquires RAR from the compensated PDSCH.

For more details about step S73, please refer to the description of steps in fig. 2 and fig. 5 for further execution, which is not described herein again.

Referring to fig. 10, fig. 10 is a schematic structural diagram of a random access apparatus according to an embodiment of the present invention. The random access device may be used for a user equipment, and may include an uplink preamble sending module 101, a PDCCH determining module 102, a TRS acquiring module 103, a PDSCH compensating module 104, a RAR acquiring module 105, a RAR uplink preamble index determining module 106, and a RAR reception success determining module 107.

The uplink preamble sending module 101 is adapted to send an uplink preamble to a base station when performing random access based on a contention mechanism;

the PDCCH determining module 102 is adapted to determine a PDCCH through blind detection according to the uplink preamble;

the TRS obtaining module 103 is adapted to obtain a TRS from a preset time-frequency resource in a time slot where the PDCCH is located;

the PDSCH compensating module 104 is adapted to compensate the PDSCH in a preset time slot according to the TRS and the time slot in which the PDCCH is located;

the RAR acquisition module 105 is adapted to acquire RAR in the compensated PDSCH;

the RAR uplink preamble index determining module 106 is adapted to determine an uplink preamble index in the RAR;

the RAR reception success determining module 107 is adapted to determine that the RAR reception is successful when the uplink preamble index carried by the RAR is consistent with the uplink preamble index.

Fig. 11 is a structural diagram of a specific embodiment of the PDCCH determining module 102 in fig. 10, and the PDCCH determining module 102 may include an RA-RNTI determining sub-module 111 and a PDCCH determining sub-module 112.

The RA-RNTI determining submodule 111 is adapted to determine an RA-RNTI according to the uplink preamble;

and the PDCCH determining submodule 112 is suitable for determining the PDCCH scrambled by the RA-RNTI through blind detection according to the RA-RNTI.

Fig. 12 is a schematic structural diagram of an embodiment of the TRS acquisition module 103 in fig. 10. The TRS acquiring module 103 may include a downlink control information acquiring submodule 121 and a TRS acquiring submodule 122.

The downlink control information obtaining sub-module 121 is adapted to obtain downlink control information in the PDCCH, where the downlink control information includes TRS indication information, and the TRS indication information is used to indicate whether to send the TRS in a time slot where the PDCCH is located;

the TRS obtaining sub-module 122 is adapted to, when the TRS indication information indicates that the TRS is sent in the time slot where the PDCCH is located, obtain the TRS in a preset time-frequency resource in the time slot where the PDCCH is located.

Further, the preset time frequency resource is a fixed time frequency position in the time slot.

Fig. 13 is a schematic structural diagram of an embodiment of the PDSCH compensating module 104 in fig. 10. The PDSCH compensating module may include a first PDSCH compensating sub-module 131 or a second PDSCH compensating sub-module 132.

The first PDSCH compensating submodule 131 is adapted to compensate the PDSCH in the time slot where the PDCCH is located according to the TRS;

the second PDSCH compensating submodule 132 is adapted to compensate the PDSCH in the nth time slot after the time slot where the PDCCH is located according to the TRS, where N is a positive integer.

Further, the TRS occupies at most one full slot.

Preferably, the slot includes 14 OFDM symbols.

For the principle, specific implementation and beneficial effects of the random access apparatus shown in fig. 10 to 13, please refer to the foregoing and the related description about the random access method shown in fig. 2 to 6, which will not be repeated herein.

Referring to fig. 14, fig. 14 is a schematic structural diagram of another random access apparatus in this embodiment, where the random access apparatus may be used in a base station, and may include an uplink preamble receiving module 141, a PDCCH configuring module 142, and a PDCCH transmitting module 143.

The uplink preamble receiving module 141 is adapted to receive an uplink preamble from a user equipment when the user equipment performs random access based on a contention mechanism;

the PDCCH configuring module 142 is adapted to configure a PDCCH to be sent according to the uplink preamble, and configure a TRS in a preset time-frequency resource in a time slot where the PDCCH is located;

the PDCCH transmitting module 143 transmits a PDCCH to the ue, so that the ue compensates a PDSCH in a preset time slot according to the TRS and a time slot in which the PDCCH is located, and acquires a RAR from the compensated PDSCH.

Fig. 15 is a schematic structural diagram of an embodiment of the PDCCH configuring module 142 in fig. 14. The PDCCH configuring module 142 may include an RA-RNTI configuring sub-module 151, a PDCCH sending sub-module 152, a downlink control information configuring sub-module 153, and a TRS configuring sub-module 154.

The RA-RNTI configuration sub-module 151 is adapted to configure an RA-RNTI according to the time-frequency resource of the uplink preamble;

the PDCCH transmitting sub-module 152 is adapted to transmit the PDCCH scrambled by the RA-RNTI to the user equipment.

The downlink control information configuring sub-module 153 is adapted to configure downlink control information in the PDCCH, where the downlink control information includes TRS indication information, and the TRS indication information is used to indicate whether to send the TRS in a time slot where the PDCCH is located;

the TRS configuring sub-module 154 is adapted to configure the TRS in a preset time-frequency resource in a time slot in which the PDCCH is located when the TRS indication information indicates that the TRS is transmitted in the time slot in which the PDCCH is located.

For the principle, specific implementation and beneficial effects of the random access apparatus shown in fig. 14 to 15, please refer to the foregoing and the related description about the random access method shown in fig. 7 to 9, which will not be repeated herein.

The embodiment of the invention also provides a storage medium, wherein computer instructions are stored on the storage medium, and the steps of the random access method are executed when the computer instructions are executed. The storage medium may be a computer-readable storage medium. The storage medium may be an optical disc, a mechanical hard disc, a solid state hard disc, etc.

An embodiment of the present invention further provides a user equipment, which includes a memory and a processor, where the memory stores computer instructions capable of being executed on the processor, and the processor executes the steps of the random access method shown in fig. 2 to 6 when executing the computer instructions.

The embodiment of the present invention further provides a base station, which includes a memory and a processor, where the memory stores computer instructions capable of being executed on the processor, and the processor executes the steps of the random access method shown in fig. 7 to 9 when executing the computer instructions.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A random access method in an idle state is characterized by comprising the following steps:

when random access based on a competition mechanism is carried out, an uplink lead code is sent to a base station;

determining a PDCCH through blind detection according to the uplink lead code;

acquiring a TRS from a preset time-frequency resource in a time slot in which the PDCCH is positioned;

compensating a PDSCH in a preset time slot according to the TRS and the time slot where the PDCCH is located; and acquiring RAR in the compensated PDSCH.

2. The random access method of claim 1, wherein the uplink preamble has an index, further comprising:

determining an uplink lead code index carried by the RAR;

and if the uplink lead code index carried by the RAR is consistent with the uplink lead code index, determining that the RAR is successfully received.

3. The random access method of claim 1, wherein the determining the PDCCH by blind detection according to the uplink preamble comprises:

determining RA-RNTI according to the time-frequency resource for sending the uplink lead code;

and determining the PDCCH scrambled by the RA-RNTI through blind detection according to the RA-RNTI.

4. The random access method according to claim 1, wherein the acquiring the TRS from the preset time-frequency resource in the time slot of the PDCCH comprises:

acquiring downlink control information in the PDCCH, wherein the downlink control information comprises TRS indication information which is used for indicating whether the TRS is sent in a time slot in which the PDCCH is located;

and if the TRS indication information indicates that the TRS is sent in the time slot in which the PDCCH is positioned, acquiring the TRS from a preset time-frequency resource in the time slot in which the PDCCH is positioned.

5. The random access method according to claim 1 or 4, wherein the predetermined time frequency resource is a fixed time frequency position in a time slot.

6. The random access method of claim 1, wherein compensating for the PDSCH in a preset time slot according to the TRS and the time slot in which the PDCCH is located comprises:

compensating the PDSCH in the time slot of the PDCCH according to the TRS;

or

And compensating the PDSCH in the Nth time slot after the time slot of the PDCCH according to the TRS, wherein N is a positive integer.

7. The random access method of claim 1, wherein the TRS occupies at most one full slot.

8. The random access method of claim 7, wherein the slot comprises 14 OFDM symbols.

9. A random access method in an idle state is characterized by comprising the following steps:

receiving an uplink lead code from user equipment when the user equipment performs random access based on a competition mechanism;

configuring a PDCCH to be sent according to the uplink lead code, and configuring a TRS (time frequency resource) in a preset time slot in which the PDCCH is located;

and sending a PDCCH to the user equipment, so that the user equipment compensates the PDSCH in a preset time slot according to the TRS and the time slot in which the PDCCH is positioned, and acquiring RAR in the compensated PDSCH.

10. The random access method of claim 9, wherein configuring the PDCCH to be transmitted according to the uplink preamble comprises:

configuring RA-RNTI according to the time-frequency resource of the uplink lead code;

and transmitting the PDCCH scrambled by the RA-RNTI to the user equipment.

11. The random access method according to claim 9, wherein configuring the TRS with a preset time-frequency resource in a time slot in which the PDCCH is located includes:

configuring downlink control information in the PDCCH, wherein the downlink control information comprises TRS indication information which is used for indicating whether the TRS is sent in a time slot in which the PDCCH is located;

and if the TRS indication information indicates that the TRS is sent in the time slot of the PDCCH, configuring the TRS in a preset time-frequency resource in the time slot of the PDCCH.

12. An idle-state random access apparatus, comprising:

the uplink lead code sending module is suitable for sending the uplink lead code to the base station when random access based on a competition mechanism is carried out;

the PDCCH determining module is suitable for determining the PDCCH through blind detection according to the uplink lead code;

the TRS acquisition module is suitable for acquiring TRS from a preset time-frequency resource in a time slot where the PDCCH is located;

the PDSCH compensation module is suitable for compensating the PDSCH in a preset time slot according to the TRS and the time slot where the PDCCH is located;

and the RAR acquisition module is suitable for acquiring RAR in the compensated PDSCH.

13. The random access apparatus of claim 12, wherein the uplink preamble has an index, further comprising:

an RAR uplink lead code index determining module, adapted to determine an uplink lead code index carried by the RAR;

and the RAR reception success determining module is adapted to determine that the RAR reception is successful when the uplink preamble index carried by the RAR is consistent with the uplink preamble index.

14. The random access apparatus of claim 12, wherein the PDCCH determining module comprises:

the RA-RNTI determining sub-module is suitable for determining RA-RNTI according to the uplink lead code;

and the PDCCH determining submodule is suitable for determining the PDCCH scrambled by the RA-RNTI through blind detection according to the RA-RNTI.

15. The random access apparatus of claim 12, wherein the TRS acquisition module comprises:

a downlink control information obtaining sub-module, adapted to obtain downlink control information in the PDCCH, where the downlink control information includes TRS indication information, and the TRS indication information is used to indicate whether to send the TRS in a time slot where the PDCCH is located;

and the TRS acquisition sub-module is suitable for acquiring the TRS in a preset time-frequency resource in the time slot of the PDCCH when the TRS indication information indicates that the TRS is transmitted in the time slot of the PDCCH.

16. The random access apparatus according to claim 12 or 15, wherein the predetermined time-frequency resource is a fixed time-frequency position in a time slot.

17. The random access apparatus of claim 12, wherein the PDSCH compensating module comprises:

the first PDSCH compensation submodule is suitable for compensating the PDSCH in the time slot where the PDCCH is located according to the TRS;

or

And the second PDSCH compensation submodule is suitable for compensating the PDSCH in the Nth time slot after the time slot where the PDCCH is located according to the TRS, wherein N is a positive integer.

18. The random access apparatus of claim 12, wherein the TRS occupies at most one full time slot.

19. The random access device of claim 18, wherein the slot comprises 14 OFDM symbols.

20. An idle-state random access apparatus, comprising:

an uplink lead code receiving module, adapted to receive an uplink lead code from a user equipment when the user equipment performs random access based on a contention mechanism;

the PDCCH configuration module is suitable for configuring a PDCCH to be sent according to the uplink lead code, and the TRS is configured on a preset time-frequency resource in a time slot where the PDCCH is located;

and the PDCCH sending module is used for sending a PDCCH to the user equipment so that the user equipment compensates the PDSCH in a preset time slot according to the TRS and the time slot where the PDCCH is located, and acquires RAR in the compensated PDSCH.

21. The random access apparatus of claim 20, wherein the PDCCH configuration module comprises:

the RA-RNTI configuration sub-module is suitable for configuring RA-RNTI according to the time frequency resource of the uplink lead code;

and the PDCCH sending sub-module is suitable for sending the PDCCH scrambled by the RA-RNTI to the user equipment.

22. The random access apparatus of claim 20, wherein the PDCCH configuration module comprises:

a downlink control information configuration submodule, adapted to configure downlink control information in the PDCCH, where the downlink control information includes TRS indication information, and the TRS indication information is used to indicate whether to send the TRS in a time slot where the PDCCH is located;

a TRS configuring sub-module, adapted to configure the TRS in a preset time-frequency resource in a time slot in which the PDCCH is located when the TRS indication information indicates that the TRS is transmitted in the time slot in which the PDCCH is located.

23. A storage medium having stored thereon computer instructions, characterized in that the computer instructions are operable to perform the steps of the random access method in idle state according to any of claims 1 to 8, or to perform the steps of the random access method in idle state according to any of claims 9 to 11.

24. A user equipment comprising a memory and a processor, said memory having stored thereon computer instructions executable on said processor, wherein said processor when executing said computer instructions performs the steps of the random access method in idle state according to any of claims 1 to 8.

25. A base station comprising a memory and a processor, said memory having stored thereon computer instructions executable on said processor, wherein said processor when executing said computer instructions performs the steps of the random access method in idle state according to any of claims 9 to 11.