CN107493608B

CN107493608B - Method and equipment for random access

Info

Publication number: CN107493608B
Application number: CN201610407288.3A
Authority: CN
Inventors: 贺媛
Original assignee: China Academy of Telecommunications Technology CATT
Current assignee: China Academy of Telecommunications Technology CATT; Datang Mobile Communications Equipment Co Ltd
Priority date: 2016-06-12
Filing date: 2016-06-12
Publication date: 2020-06-05
Anticipated expiration: 2036-06-12
Also published as: WO2017215437A1; TWI676400B; TW201743650A; CN107493608A

Abstract

The embodiment of the invention relates to the technical field of wireless communication, in particular to a method and equipment for random access, which are used for solving the problems that in the prior art, in the current network intensive deployment scene, because the coverage area of each cell is small, when UE moves, the UE can frequently read the random access information in the system information of the cell, so that the UE consumes power and is complex to process. The network side equipment of the embodiment of the invention sends the terminal the same specific random access information as a plurality of other network side equipment, and the terminal carries out random access through the same specific random access information sent by the plurality of network side equipment. The same specific random access information sent by the network side equipment enables the terminal not to need to frequently read the random access information in the system information of the cell, thereby reducing the power consumption of the terminal and the processing complexity; further improving the system performance.

Description

Method and equipment for random access

Technical Field

The present invention relates to the field of wireless communications technologies, and in particular, to a method and a device for performing random access.

Background

Contention random access refers to random access initiated by UE (evolved base station) randomly selecting a Preamble code without eNB (evolved base station) allocating a dedicated Preamble code to UE (terminal). The contention random access procedure is divided into 4 steps as shown in fig. 1A. Each step is called a message (message), and the 4 steps are called Msg 1-Msg 4.

Msg 1: and sending a Preamble code.

The eNB is responsible for configuring a Preamble code and a PRACH (Physical random access Channel) resource for transmitting the Preamble code, and broadcasts the configuration to the UE residing in the cell through an SI (System Information)

Msg 2: and (4) random access response.

The eNB sends the Msg2 in a random access response window;

and the UE receives the Msg2 in the random access response window, if the receiving fails, the time for initiating the next random access is determined according to a backoff (backoff) delay parameter, and a random access resource is selected to initiate the next random access.

Msg 3: the first time the transmission is scheduled.

The UE transmits Msg3 on the allocated uplink resource.

Msg 4: and (5) resolving the competition.

The Msg4 contains information related to contention resolution, and the UE considers that contention resolution is successful after receiving the information.

And the UE does not receive the Msg4 when the contention resolution timer is overtime, and if the contention resolution is considered to be failed, the time for initiating the next random access is determined according to the backoff time delay parameter, and the random access resource is selected to initiate the next random access.

The non-contention random access is random access initiated by the UE on the designated PRACH channel resource by using the designated Preamble code according to the instruction of the eNB. The non-contention random access is divided into 3 steps as shown in fig. 1B. These 3 steps are referred to as Msg0 to Msg 2.

Msg 0: a random access indication.

The eNB will actively require the designated UE to initiate a random access process during handover and downlink data arrival.

The Msg0 contains Preamble codes and PRACH channel resources used by the UE to initiate non-contention random access.

Msg 1: and sending a Preamble code.

And the UE initiates random access on the PRACH channel resource appointed by the eNB by using an appointed Preamble code. If a plurality of PRACH channel resources are specified, the UE randomly selects a specified PRACH channel resource for carrying the Msg1 in the first available subframe with the PRACH channel resource.

Msg 2: and (4) random access response.

The format and content of Msg2 is the same as for contention random access.

If the UE does not receive the random access response in the random access response window, the UE judges that the non-competitive random access fails, and initiates random access on the next appointed PRACH channel resource by using an appointed Preamble code without the limitation of a backoff parameter.

At present, access information such as Preamble codes of each cell is different, and when a UE camps in a certain cell, the UE initiates a random access process according to an indication of system information, and only the corresponding cell can receive and perform feedback. In a network intensive deployment scenario, the coverage area of each cell is relatively small, and when the UE moves, the UE may frequently read the random access information in the system information of the cell, which results in power consumption and complex processing of the UE.

In summary, in the current network intensive deployment scenario, because the coverage area of each cell is relatively small, when the UE moves, the UE may frequently read the random access information in the system information of the cell, which results in power consumption and complex processing of the UE.

Disclosure of Invention

The embodiment of the invention provides a method and equipment for random access, which are used for solving the problems that in the prior art, in the current network intensive deployment scene, because the coverage area of each cell is relatively small, when UE moves, the UE can frequently read the random access information in the system information of the cell, so that the UE consumes power and is complex to process.

The method for random access provided by the embodiment of the invention comprises the following steps:

the network side equipment determines the same specific random access information with a plurality of other network side equipment;

and the network side equipment sends the specific random access information to a terminal so that the terminal can access through the random access information.

Optionally, the determining, by the network side device, the random access information that is the same as that of the multiple other network side devices includes:

and the network side equipment receives the specific random access information from the control equipment.

Optionally, the sending, by the network side device, the specific random access information to the terminal includes:

and the network side equipment sends the specific random access information to a terminal through broadcasting or special signaling.

Optionally, after the network side device sends the specific random access information to the terminal, the method further includes:

the network side equipment receives a first message which is sent by the terminal and contains a lead code in the random access information;

and the network side equipment sends a second message containing random access response information in a random access response window.

Optionally, after the network side device receives the first message that includes the preamble in the random access information and is sent by the terminal, before sending the second message that includes the random access response information in the random access response window, the method further includes:

and the network side equipment reports the first message to the control equipment and determines to receive a first sending instruction of the control equipment.

Optionally, the control device notifies the first sending instruction to a plurality of network-side devices;

before the network side device sends the second message containing the random access response information in the random access response window, the method further includes:

the network side equipment and other network side equipment receiving the first sending instruction use a Physical Downlink Control Channel (PDCCH) to schedule the second message at the same time, and address the second message through an RA-RNTI;

the sending of the second message containing the random access response information in the random access response window of the network side device includes:

and the network side equipment and other network side equipment receiving the first sending instruction send second messages containing the same random access response information.

and the network side equipment and other network side equipment receiving the first sending indication send a second message containing the same random access response information through the same time-frequency resource at the same time.

Optionally, the sending, by the network side device, the second message including the random access response information in the random access response window includes:

and the network side equipment sends a second message containing random access response information in a random access response window according to the uplink resource configured by the control equipment and the temporary cell radio network temporary identifier C-RNTI.

Optionally, before the network side device sends the second message including the random access response information in the random access response window, the method further includes:

and the network side equipment determines that the sending condition is met according to the measurement information of the received first message.

Optionally, after the network side device sends the second message including the random access response information in the random access response window, the method further includes:

the network side equipment sends a received third message containing competition information of the terminal and measurement information for receiving the third message to the control equipment;

and after receiving the second sending instruction of the control device, the network side device sends a fourth message containing competition resolving information to the terminal.

the control equipment determines specific random access information;

the control device sends the specific random access information to a plurality of network side devices, so that the network side devices send the specific random access information to a terminal, and the terminal performs access through the random access information.

Optionally, after the controlling device sends the specific random access information to a plurality of network-side devices, the method further includes:

the control equipment receives first messages which are reported by a plurality of network side equipment and are sent by the same terminal and contain lead codes in the random access information;

the control device selects at least one network side device from the plurality of network side devices, and notifies the selected network side device of a first sending instruction, so that the network side device sends a second message containing random access response information to the terminal.

Optionally, the selecting, by the control device, at least one network-side device from the plurality of network-side devices includes:

and the control equipment selects at least one network side equipment from the plurality of network side equipment according to the measurement information of the first message received by each network side equipment.

Optionally, the method further includes:

the control device allocates different uplink resources and temporary C-RNTIs to the plurality of network side devices, so that the network side devices send a second message containing random access response information in a random access response window through the uplink resources and the temporary C-RNTIs after receiving a first message containing a lead code in the random access information sent by a terminal.

the control equipment receives third messages which are reported by a plurality of network side equipment and are sent by the same terminal and contain competition information, and the measurement information of the third messages received by the plurality of network side equipment is sent to the control equipment;

the control device selects at least one network side device from the plurality of network side devices according to the measurement information of the third message received by each network side device, and notifies the selected network side device of a second sending instruction, so that the network side device sends a fourth message containing contention resolution information to the terminal.

the terminal receives the same specific random access information sent by a plurality of network side devices;

and the terminal carries out random access according to the specific random access information.

Optionally, the performing, by the terminal, random access according to the specific random access information includes:

the terminal sends a first message containing a lead code in the specific random access information to part or all of the network side equipment in the plurality of network side equipment through the time-frequency resource in the specific random access information;

and the terminal receives a second message which is sent by at least one piece of network side equipment and contains the same random access response information.

Optionally, the terminal places a preamble bound to the terminal in the specific random access information in the first message.

Optionally, the terminal places a terminal identifier in the first message.

Optionally, after the terminal receives a second message that contains the same random access response information and is sent by at least one of the network side devices, the method further includes:

the terminal sends a third message containing competition information to at least one network side device sending the second message;

and the terminal receives a fourth message which is sent by at least one network side device and contains competition resolving information.

Optionally, the terminal receives a plurality of second messages; the terminal sends a third message containing competition information to at least one network side device sending the second message, and the third message comprises:

if the uplink timing advance (UL TA) in the second messages are different, the terminal selects at least one UL TA and sends a third message containing competition information according to the selected UL TA; or

And if the uplink grant UL grant and the temporary C-RNTI in the second messages are different, the terminal selects at least one group of UL grant and temporary C-RNTI and sends a third message containing competition information according to the selected UL grant and temporary C-RNTI.

Optionally, the sending, by the terminal, a third message including contention information according to the selected UL grant and the temporary C-RNTI includes:

and when the terminal needs to send a plurality of third messages, sending the third messages scrambled by different temporary C-RNTIs on different uplink resources of the same subframe according to the selected UL grant.

The network side device for performing random access provided by the embodiment of the invention comprises:

the first information determining module is used for determining the specific random access information which is the same as the specific random access information of a plurality of other network side devices;

and the first processing module is used for sending the specific random access information to a terminal so that the terminal can access through the random access information.

Optionally, the first information determining module is specifically configured to:

receiving the specific random access information from a control device.

Optionally, the first processing module is specifically configured to:

the specific random access information is transmitted to the terminal through broadcasting or dedicated signaling.

Optionally, the first processing module is further configured to:

receiving a first message which is sent by the terminal and contains a lead code in the random access information; and sending a second message containing the random access response information in the random access response window.

Optionally, the first processing module is further configured to:

and reporting the first message to the control equipment, and after determining that the first sending instruction of the control equipment is received, sending a second message containing random access response information in a random access response window.

the first processing module is further configured to:

the second message is scheduled by using the PDCCH at the same time with other network side equipment receiving the first sending instruction, and is addressed through the RA-RNTI; and sending a second message containing the same random access response information with other network side equipment receiving the first sending instruction.

the first processing module is specifically configured to:

and sending a second message containing the same random access response information through the same time-frequency resource at the same time with other network side equipment receiving the first sending instruction.

Optionally, the first processing module is specifically configured to:

and sending a second message containing random access response information in a random access response window according to the uplink resource and the temporary C-RNTI configured by the control equipment.

Optionally, the first processing module is further configured to:

and after the sending condition is determined to be met according to the measurement information of the received first message, sending a second message containing the random access response information in a random access response window.

Optionally, the first processing module is further configured to:

after sending a second message containing random access response information in a random access response window, sending a received third message containing contention information of the terminal and measurement information for receiving the third message to the control device; and after receiving a second sending instruction of the control equipment, sending a fourth message containing competition resolving information to the terminal.

The control device for performing random access provided by the embodiment of the present invention includes:

a second information determining module for determining specific random access information;

and the second processing module is used for sending the specific random access information to a plurality of network side devices, so that the plurality of network side devices send the specific random access information to a terminal, and the terminal performs access through the random access information.

Optionally, the second processing module is further configured to:

after the control device sends the specific random access information to a plurality of network side devices, receiving a first message which is reported by the plurality of network side devices and sent by the same terminal and contains a lead code in the random access information; and selecting at least one network side device from the plurality of network side devices, and notifying the selected network side device of the first sending indication, so that the network side device sends a second message containing random access response information to the terminal.

Optionally, the second processing module is specifically configured to:

and selecting at least one network side device from the plurality of network side devices according to the measurement information of the first message received by each network side device.

Optionally, the second processing module is further configured to:

and allocating different uplink resources and temporary C-RNTIs to the plurality of network side devices, so that the network side devices send a second message containing random access response information in a random access response window through the uplink resources and the temporary C-RNTIs after receiving a first message containing a lead code in the random access information sent by a terminal.

Optionally, the second processing module is further configured to:

after the specific random access information is sent to a plurality of network side devices, receiving third messages which are reported by the plurality of network side devices and sent by the same terminal and contain competition information, and sending measurement information of the plurality of network side devices, which receives the third messages, to the control device; and selecting at least one network side device from the plurality of network side devices according to the measurement information of the third message received by each network side device, and notifying the selected network side device of a second sending instruction, so that the network side device sends a fourth message containing competition resolving information to the terminal.

The terminal for performing random access provided by the embodiment of the invention comprises:

the receiving module is used for receiving the same specific random access information sent by a plurality of network side devices;

and the access module is used for carrying out random access according to the specific random access information.

Optionally, the access module is specifically configured to:

sending a first message containing a lead code in the specific random access information to part or all of the network side equipment in the plurality of network side equipment through a time-frequency resource in the specific random access information; and receiving a second message which is sent by at least one piece of network side equipment and contains the same random access response information.

Optionally, the access module is further configured to:

placing a preamble bound to the terminal in the specific random access information in the first message.

Optionally, the access module is further configured to:

placing a terminal identification in the first message.

Optionally, the access module is further configured to:

after receiving a second message which is sent by at least one network side device and contains the same random access response information, sending a third message containing competition information to at least one network side device which sends the second message; and receiving a fourth message which is sent by at least one network side device and contains the competition resolving information.

Optionally, the terminal receives a plurality of second messages;

the access module is specifically configured to:

if the UL TAs in the plurality of second messages are different, selecting at least one UL TA, and sending a third message containing competition information according to the selected UL TA; or

And if the UL grant and the temporary C-RNTI in the plurality of second messages are different, selecting at least one group of UL grant and temporary C-RNTI, and sending a third message containing competition information according to the selected UL grant and temporary C-RNTI.

Optionally, the access module is specifically configured to:

and when a plurality of third messages need to be sent, sending the third messages scrambled by different temporary C-RNTIs on different uplink resources of the same subframe according to the selected UL grant.

The network side equipment of the embodiment of the invention sends the terminal the same specific random access information as a plurality of other network side equipment, and the terminal carries out random access through the same specific random access information sent by the plurality of network side equipment. The same specific random access information sent by the network side equipment enables the terminal not to need to frequently read the random access information in the system information of the cell, thereby reducing the power consumption of the terminal and the processing complexity; further improving the system performance.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1A is a diagram illustrating contention for random access in the background art;

FIG. 1B is a diagram illustrating non-contention random access in the background art;

fig. 2A is a schematic diagram of a cell in a scenario 5G according to embodiment 5G, where each TRP (Transmission Reception Point) is a Transmission Reception Point;

fig. 2B is a schematic diagram of a scenario 5G in which multiple TRPs are a cell according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a system for performing random access according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a first network-side device according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram of a first control device according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a first terminal according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a second network-side device according to an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a second control apparatus according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of a second terminal according to an embodiment of the present invention;

fig. 10 is a flowchart illustrating a first method for performing random access according to a first embodiment of the present invention;

fig. 11 is a flowchart illustrating a second method for performing random access according to a second embodiment of the present invention;

fig. 12 is a flowchart illustrating a third method for performing random access according to an embodiment of the present invention;

FIG. 13 is a flowchart illustrating a non-contention random access method according to an embodiment of the present invention;

FIG. 14 is a flowchart illustrating a method for contention random access according to an embodiment of the present invention;

fig. 15 is a diagram of random access under ideal fronthaul/backhaul for multiple TRP cells in accordance with an embodiment of the present invention;

fig. 16 is a diagram of random access under a multi-TRP cell non-ideal fronthaul/backhaul in accordance with an embodiment of the present invention;

fig. 17 is a diagram illustrating random access under ideal forward/return of a virtual cell in accordance with an embodiment of the present invention;

fig. 18 is a diagram of random access under virtual cell non-ideal fronthaul/backhaul in accordance with an embodiment of the present invention.

Detailed Description

The scheme of the embodiment of the invention can be applied to any network intensive deployment scene. A network-intensive deployment scenario is listed below.

As shown in fig. 2A and 2B, the 5G scenario is a network-intensive deployment scenario.

1. CU (central unit, centralized node):

the centralized node, also called central processing unit, also called control device, can manage and control a plurality of transmission reception points TRP, a CU can be an upper node. For example, an independent access network node: a Local Gateway (Local Gateway) or a Local Controller (Local Controller), or a core network node or an OAM (Operation administration and Maintenance) node; the base station can also be a super base station, and the base station can manage a plurality of base stations and can be regarded as the super base station; or a baseband pool in a C-RAN architecture (where the C-RAN in the embodiment of the present invention may be a Centralized Radio Access Network (RAN) or a Cloud Radio access network (Cloud-RAN)), and collectively process baseband signals of multiple RRHs (Remote Radio heads); or may be a CU with part of the functionality of the protocol stack.

2. A base station:

the base station is also called as a TRP (Transmission Reception Point), which may be a macro station, such as an eNB, NB (base station), etc.; or a small station, such as an LPN (low power node), an AP (access point), etc.; or RRH in C-RAN architecture; or a DU (Distributed Unit) with partial protocol stack functionality. One or more cells (different frequency bins or sector divisions) are under a TRP, or one or more TRPs constitute a Virtual Cell (Virtual Cell).

Under the 5G network, a plurality of TRPs are controlled by a central node CU, a TRP next TRP cell or a plurality of TRPs form a virtual cell, and ideal forward transmission (frontaul)/backward transmission (backhaul) or non-ideal forward transmission/backward transmission is performed between the TRP and the CU.

Under the 5G network intensive deployment scene, the working frequency of the TRP is a frequency band below 6GHz or above 6GHz, a typical working frequency band: 3.4 to 3.6GHz (LTE TDD Band 42) at 6GHz or less; more than 6GHz, 30GHz outdoor high frequency band and 70GHz indoor high frequency band.

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 3, the system for performing random access according to the embodiment of the present invention includes: network side device 10, control device 20 and terminal 30.

A network side device 10, configured to determine specific random access information that is the same as that of multiple other network side devices; sending the specific random access information to a terminal;

a control device 20 for determining specific random access information; sending the specific random access information to a plurality of network side devices;

the terminal 30 is configured to receive the same specific random access information sent by multiple network-side devices; and carrying out random access according to the specific random access information.

The control equipment of the embodiment of the invention can configure the same specific random access information for a plurality of network side equipment;

correspondingly, the network side device receives the specific random access information from the control device.

The specific random access information includes, but is not limited to, part or all of the following information:

preamble code, Root sequence, Preamble transmission power, PRACH time-frequency resource, random access response window, and conflict resolution timer.

In implementation, the control device may allocate the same specific random access information to some or all of the network-side devices managed by the control device; the network side devices may be divided into regions, and the network side devices in the same region may be assigned the same specific random access information.

Optionally, the network side device sends the specific random access information to the terminal through broadcasting or dedicated signaling (e.g., an on-demand manner).

The specific random access information may be used for either a contention random access or a non-contention random access procedure. For example, specific random access information for contention random access is broadcast in the system information, and specific random access information for non-contention random access is transmitted by the dedicated signaling. In an implementation, a plurality of TRPs may transmit specific random access information simultaneously.

When the terminal receives the same specific random access information sent by a plurality of network side devices, if the specific random access information contains Preamble codes, the terminal can randomly select the Preamble codes; if the specific random access information contains PRACH time frequency resources, the PRACH time frequency resources can be randomly selected.

The terminal may transmit a first message (i.e., Msg1) including the selected preamble through the selected PRACH time-frequency resource.

If a plurality of network side devices synchronously send specific random access information, the terminal is superposed with a plurality of synchronous signals when receiving, which is beneficial to the terminal to accurately receive the random access information.

For the competitive random access, a plurality of terminals may select the same Preamble code and different PRACH time-frequency resources; or different Preamble codes and the same PRACH time-frequency resource, so contention resolution is required.

For non-contention random access, the random access information corresponding to the first message is bound or mapped (mapping) with the terminal identifier, so contention resolution is not required.

The terminal label bound with the terminal may be configured by the network side to the terminal, for example, the control device is sent to the network side device through the Msg0, and the network side device sends the control device to the terminal.

Optionally, the terminal sends, to some or all of the network side devices in the multiple network side devices, a first message including a preamble in the specific random access information through a time-frequency resource in the specific random access information;

the network side equipment sends a second message (namely Msg2) containing random access response information in a random access response window;

The network side device sends the second message in the random access response window in two manners, one is an ideal forwarding/returning manner between the network side device and the control device, and the other is a non-ideal forwarding/returning manner between the network side device and the control device, which is described in detail below.

Firstly, an ideal forward/backward transmission mode is realized between the network side equipment and the control equipment.

In this way, after receiving a first message which is sent by the terminal and contains a preamble in the random access information, the network side device reports the first message to the control device;

correspondingly, the control device receives a first message which is reported by a plurality of network side devices and is sent by the same terminal and contains the lead code in the random access information;

the control device selects at least one network side device from the plurality of network side devices and notifies the selected network side device of a first sending instruction;

and after determining that the first sending instruction of the control equipment is received, the network side equipment sends a second message containing random access response information in a random access response window.

Optionally, when the control device selects at least one network-side device from the multiple network-side devices, the control device may select at least one network-side device from the multiple network-side devices according to measurement information of the first message received by each network-side device.

For example, the control device selects the network-side device with the best received signal to reply the second message, or selects some or all network-side devices from the plurality of network-side devices with the received signals satisfying the condition to reply the same second message.

Specifically, the control device selects the network side device with the maximum received signal strength according to the measurement information; or

The control equipment selects the network side equipment with the best signal quality according to the measurement information; or

And the control equipment selects part or all of the network side equipment of which the received signal strength meets the first threshold and/or the signal quality meets the second threshold according to the measurement information. Optionally, if multiple network-side devices are selected, the multiple network-side devices reply to the same second message, which may be for reliable transmission. The first threshold and the second threshold may be configured by a control device, may also be configured by a network side device, and may also be configured manually.

And after receiving the first sending instruction, the one or more network side devices send a second message in the random access response window. Since the coordination processing is performed by the control device, when the plurality of Network side devices transmit the second message, the transmission may be a multipoint transmission diversity transmission, which is equivalent to a Single Frequency Network (SFN) transmission.

Optionally, the network side device and the other network side devices that receive the first sending instruction use a PDCCH (Physical Downlink Control Channel) to schedule the second message at the same time, and address the second message through an RA-RNTI;

Specifically, a plurality of network side devices use the PDCCH to schedule a second device at the same time, and address through RA-RNTI;

the plurality of network-side devices schedule the second message on the same PDCCH resource (e.g., CCE), and the content of the scheduled second message is the same, that is, the parameters contained in the Msg2 are the same. Or one of the network side devices uses the PDCCH to schedule the second message, and the network side devices send the second message with the same content on the same time-frequency resource at the same time. If one network side device schedules the second message, the resource for sending the second message may be that the control device informs other network side devices to realize that a plurality of network side devices send the same second message at the same time. Of course, it may also be specified in the protocol.

And secondly, a non-ideal forward transmission/return transmission mode is adopted between the network side equipment and the control equipment.

This is to reduce the access delay, so that the multiple network-side devices send the second message without coordination by the control device.

If the non-ideal forward/backward transmission is the case of ideal time delay and non-ideal throughput, the second message may be sent by the control device, which is similar to the operation of the ideal forward/backward transmission and is not described herein again.

The following is the operation in the case where the non-ideal fronthaul/backhaul delay is not ideal.

The control equipment allocates different uplink resources and temporary C-RNTIs for the plurality of network side equipment;

correspondingly, after receiving the first message which is sent by the terminal and contains the lead code in the random access information, the network side equipment sends a second message which contains the random access response information in a random access response window according to the uplink resource and the temporary CRNTI configured by the control equipment.

Specifically, the control device allocates different uplink resources and Temporary C-RNTIs (Cell Radio Network Temporary identifiers) to multiple Network side devices that transmit the same random access information in advance, so as to ensure no collision.

After the plurality of network side devices receive the first message sent by the terminal, each network side device generates a second message and sends the second message in the random access response window. The second messages generated by the multiple network side devices may be the same or different; if the uplink resource and the temporary C-RNTI (similar to an RA-RNTI (random access-radio network temporary identifier) and serving as addressing) contained in the second message are different, the backoff parameter and the UL TA (uplink timing advance) may be the same or different, and the same as the Preamble code corresponding to the first message and the same as the RA-RNTI for addressing.

Further, the network side device judges whether a sending condition is met according to the measurement information of the received first message, and sends a second message containing the random access response information in the random access response window after the sending condition is determined to be met.

The network side devices judge whether the conditions are met or not according to the measurement information of the received first message, for example, whether the received signal strength meets a third threshold value or/and whether the signal quality meets a fourth threshold value or/and the network side devices meeting the conditions reply the second message.

In order to reduce the access delay, the terminal places a terminal identity in the first message for simplifying the random access procedure, e.g. changing 4-step random access into 2-step random access.

Since the first message includes the terminal identification information, the control device needs to obtain the context of the terminal through the terminal identification information, and this process requires interaction between the control device and the core network CN (for example, authentication, and other processes during initial access, or UE identification during switching), multiple network side devices send the first message to the control device, and the control device schedules the network side device to send the second message. Since the control device has already identified the terminal by the first message, the terminal does not need to perform contention resolution.

For the non-contention random access procedure, the terminal finishes the intervention procedure after successfully receiving one or more second messages in the random response window.

If the terminal fails to receive, determining the time for initiating the next random access according to a backoff (backoff) time delay parameter, and selecting a random access resource to initiate the next random access.

For the contention random access process, since the terminal needs to perform contention resolution, the terminal successfully receives one or more second messages in the random response window and then sends a third message containing contention information to at least one network side device sending the second messages.

Correspondingly, the network side device sends the received third message containing the competition information of the terminal and the measurement information for receiving the third message to the control device;

the control device selects at least one network side device from a plurality of network side devices according to the measurement information of the third message received by each network side device, and notifies the selected network side device of a second sending instruction, so that the network side device sends a fourth message containing competition resolving information to the terminal;

after receiving the second sending instruction of the control device, the network side device sends a fourth message containing competition resolving information to the terminal;

The third message sent by the terminal includes terminal Identity information (e.g., initial terminal Identity or reestablishment terminal Identity) and/or C-RNTI of the terminal.

And if the terminal receives a second message in the random response window, the terminal sends a third message according to the information contained in the second message.

If the terminal receives a plurality of second messages sent by a plurality of network side devices in the random response window, the terminal can select one or more second messages and send a third message according to the information in the selected second messages. Specifically, if the UL TAs included in the plurality of second messages are different, the terminal selects one UL TA to transmit one or more third messages. If the UL grant and the temporary C-RNTI included in the plurality of second messages are different, the medium terminal may select one or more sets of UL grant (uplink grant) and temporary C-RNTI to transmit one or more third messages.

Specifically, if the UL TAs in the second messages are different, the terminal selects at least one UL TA, and sends a third message including contention information according to the selected UL TA; or

And if the UL grant and the temporary C-RNTI in the plurality of second messages are different, the terminal selects at least one group of UL grant and temporary C-RNTI, and sends a third message containing competition information according to the selected UL grant and temporary C-RNTI.

Further, when the terminal receives a plurality of second messages sent by a plurality of network side devices in the same subframe, and the terminal sends a plurality of third messages, if the UL grant and the temporary C-RNTI are different, the UE sends third messages with the same content but different scrambling on different uplink resources in the same subframe. That is, the terminal sends the third messages scrambled by different temporary C-RNTIs on different uplink resources of the same subframe according to the selected UL grant, where the contents of the plurality of third messages to be sent are the same.

Because the identifier information and/or the C-RNTI of the terminal included in the third message need to be processed by the control device, the one or more network side devices send the third message to the control device, and report measurement information of receiving the third message, including received signal strength, signal quality, and the like.

The control device identifies the terminal through the terminal identification information and/or the C-RNTI of the terminal, performs contention resolution decision, and schedules the network side device to transmit the fourth message, that is, selects the best network side device to transmit the fourth message or selects a plurality of network side devices meeting the condition to transmit the same fourth message.

Specifically, if the terminals indicated in the third message sent by one or more network-side devices are the same, the control device performs contention resolution decision and schedules the network-side device to send a fourth message, where the fourth message includes contention resolution information of the terminal;

if the terminals indicated in the third message sent by one or more network side devices are different, the control device makes a contention resolution decision and schedules the network side device to send a fourth message, wherein different fourth messages contain contention resolution information of different terminals.

After the terminal receives the fourth message containing the information related to the contention resolution, the terminal considers that the contention resolution is successful.

And if the terminal fails to receive the second message, determining the time for initiating the next random access according to the backoff time delay parameter, and selecting the random access resource to initiate the next random access.

And if the terminal fails to receive the fourth message, determining the time for initiating the next random access according to the backoff time delay parameter, and selecting the random access resource to initiate the next random access.

The network side device in the embodiment of the present invention may be a base station, where the base station may also be referred to as a TRP, and the TRP may be a macro station, such as an eNB, an NB, or the like; the network side equipment of the embodiment of the invention can also be small stations such as LPN, AP and the like; the network side equipment of the embodiment of the invention can also be an RRH in a C-RAN architecture; the network side device of the embodiment of the present invention may also be a DU having a partial protocol stack function.

As shown in fig. 4, a first network-side device according to an embodiment of the present invention includes:

a first information determining module 400, configured to determine specific random access information that is the same as that of multiple other network-side devices;

a first processing module 401, configured to send the specific random access information to a terminal, so that the terminal performs access through the random access information.

Optionally, the first information determining module 400 is specifically configured to:

receiving the specific random access information from a control device.

Optionally, the first processing module 401 is specifically configured to:

Optionally, the first processing module 401 is further configured to:

the first processing module 401 is further configured to:

the first processing module 401 is specifically configured to:

Optionally, the first processing module 401 is specifically configured to:

and sending a second message containing random access response information in a random access response window according to the uplink resource and the temporary CRNTI configured by the control equipment.

Optionally, the first processing module 401 is further configured to:

As shown in fig. 5, a first control apparatus according to an embodiment of the present invention includes:

a second information determining module 500 for determining specific random access information;

a second processing module 501, configured to send the specific random access information to multiple network-side devices, so that the multiple network-side devices send the specific random access information to a terminal, and the terminal performs access through the random access information.

Optionally, the second processing module 501 is further configured to:

Optionally, the second processing module 501 is specifically configured to:

Optionally, the second processing module 501 is further configured to:

As shown in fig. 6, a first terminal according to an embodiment of the present invention includes:

a receiving module 600, configured to receive the same specific random access information sent by multiple network-side devices;

an access module 601, configured to perform random access according to the specific random access information.

Optionally, the access module 601 is specifically configured to:

Optionally, the access module 601 is further configured to:

placing a terminal identification in the first message.

Optionally, the access module 601 is further configured to:

Optionally, the terminal receives a plurality of second messages;

the access module 601 is specifically configured to:

Optionally, the access module 601 is specifically configured to:

As shown in fig. 7, a second network-side device according to the embodiment of the present invention includes:

a processor 701, configured to read the program in the memory 704, and execute the following processes:

determining specific random access information which is the same as a plurality of other network side devices; the specific random access information is transmitted to the terminal through the transceiver 702 so that the terminal performs access through the random access information.

A transceiver 702 for receiving and transmitting data under the control of the processor 701.

Optionally, the processor 701 is specifically configured to:

receiving the specific random access information from a control device.

Optionally, the processor 701 is specifically configured to:

Optionally, the processor 701 is further configured to:

the processor 701 is further configured to:

the processor 701 is specifically configured to:

Optionally, the processor 701 is specifically configured to:

Optionally, the processor 701 is further configured to:

The processor 701 performs transmission and reception through the transceiver 702.

In fig. 7, a bus architecture (represented by bus 700), bus 700 may include any number of interconnected buses and bridges, bus 700 linking together various circuits including one or more processors, represented by processor 701, and memory, represented by memory 704. The bus 700 may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. A bus interface 703 provides an interface between the bus 700 and the transceiver 702. The transceiver 702 may be one element or multiple elements, such as multiple receivers and transmitters, providing a means for communicating with various other apparatus over a transmission medium. Data processed by processor 701 is transmitted over a wireless medium via antenna 705, which antenna 705 receives data and transmits data to processor 701.

The processor 701 is responsible for managing the bus 700 and general processing, and may also provide various functions including timing, peripheral interfaces, voltage regulation, power management, and other control functions. And memory 704 may be used to store data used by processor 701 in performing operations.

Alternatively, the processor 701 may be a CPU (central processing unit), an ASIC (Application specific integrated Circuit), an FPGA (Field Programmable Gate Array), or a CPLD (Complex Programmable Logic Device).

As shown in fig. 8, a second control apparatus according to an embodiment of the present invention includes:

the processor 801 is used for reading the program in the memory 804 and executing the following processes:

determining specific random access information; the specific random access information is sent to a plurality of network side devices through the transceiver 802, so that the plurality of network side devices send the specific random access information to a terminal, and the terminal performs access through the random access information.

A transceiver 802 for receiving and transmitting data under the control of the processor 801.

Optionally, the processor 801 is further configured to:

Optionally, the processor 801 is specifically configured to:

Optionally, the processor 801 is further configured to:

Wherein, the above-mentioned sending and receiving of the processor 801 are performed through the transceiver 802.

In fig. 8, a bus architecture (represented by bus 800), bus 800 may include any number of interconnected buses and bridges, bus 800 linking together various circuits including one or more processors, represented by processor 801, and memory, represented by memory 804. The bus 800 may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. A bus interface 803 provides an interface between the bus 800 and the transceiver 802. The transceiver 802 may be one element or may be multiple elements, such as multiple receivers and transmitters, providing a means for communicating with various other apparatus over a transmission medium. Data processed by the processor 801 is transmitted over a wireless medium via the antenna 805, and further, the antenna 805 receives data and transmits data to the processor 801.

The processor 801 is responsible for managing the bus 800 and general processing and may also provide various functions including timing, peripheral interfaces, voltage regulation, power management, and other control functions. And memory 804 may be used to store data used by processor 801 in performing operations.

Alternatively, the processor 801 may be a CPU, ASIC, FPGA or CPLD.

As shown in fig. 9, a second terminal according to an embodiment of the present invention includes:

a processor 901 for reading the program in the memory 904, and executing the following processes:

receiving, by the transceiver 902, the same specific random access information sent by multiple network-side devices; and carrying out random access according to the specific random access information.

A transceiver 902 for receiving and transmitting data under the control of the processor 901.

Optionally, the processor 901 is specifically configured to:

Optionally, the processor 901 is further configured to:

placing a terminal identification in the first message.

Optionally, the processor 901 is further configured to:

Optionally, the terminal receives a plurality of second messages;

the processor 901 is specifically configured to:

Optionally, the processor 901 is specifically configured to:

The above-mentioned sending and receiving of the processor 901 are performed by the transceiver 902.

In fig. 9, a bus architecture (represented by the bus 900), the bus 900 may include any number of interconnected buses and bridges, with the bus 900 linking together various circuits including one or more processors, represented by the general purpose processor 901, and memory, represented by the memory 904. The bus 900 may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. A bus interface 903 provides an interface between the bus 900 and the transceiver 902. The transceiver 902 may be one element or multiple elements, such as multiple receivers and transmitters, providing a means for communicating with various other apparatus over a transmission medium. For example: the transceiver 902 receives external data from other devices. The transceiver 902 is used for transmitting the data processed by the processor 901 to other devices. Depending on the nature of the computing system, a user interface 905, such as a keypad, display, speaker, microphone, joystick, may also be provided.

The processor 901 is responsible for managing the bus 900 and general processing, such as running a general-purpose operating system as described above. And memory 904 may be used to store data used by processor 901 in performing operations.

Alternatively, the processor 901 may be a CPU, ASIC, FPGA or CPLD.

Based on the same inventive concept, the embodiment of the present invention further provides a method for performing random access, and since the principle of the method for solving the problem is similar to that of the system for performing random access in the embodiment of the present invention, the implementation of the method can refer to the implementation of the network side device in the system, and repeated details are not described again.

As shown in fig. 10, a first method for performing random access according to an embodiment of the present invention includes:

step 1000, the network side device determines the same specific random access information as a plurality of other network side devices;

step 1001, the network side device sends the specific random access information to a terminal, so that the terminal performs access through the random access information.

Based on the same inventive concept, the embodiment of the present invention further provides a method for performing random access, and since the principle of the method for solving the problem is similar to that of the system for performing random access in the embodiment of the present invention, the implementation of the method can refer to the implementation of the control device in the system, and repeated details are not repeated.

As shown in fig. 11, a second method for performing random access according to the embodiment of the present invention includes:

step 1100, the control device determines specific random access information;

step 1101, the control device sends the specific random access information to a plurality of network side devices, so that the plurality of network side devices send the specific random access information to a terminal, and the terminal performs access through the random access information.

Optionally, the method further includes:

Based on the same inventive concept, the embodiment of the present invention further provides a method for performing random access, and since the principle of the method for solving the problem is similar to that of the system for performing random access in the embodiment of the present invention, the implementation of the method can refer to the implementation of the terminal in the system, and repeated details are not repeated.

As shown in fig. 12, a third method for performing random access according to the embodiment of the present invention includes:

step 1200, a terminal receives the same specific random access information sent by a plurality of network side devices;

step 1201, the terminal performs random access according to the specific random access information.

Optionally, the terminal places a terminal identifier in the first message.

In the following, non-contention random access and contention random access according to the present invention are described in a scenario where multiple TRPs transmit the same specific random access information and a UE and multiple TRPs perform random access in a 5G network dense deployment scenario, and specifically refer to fig. 13 and fig. 14.

As shown in fig. 13, the method for non-contention random access according to the embodiment of the present invention includes:

step 1301: the CU configures the same specific random access information to a plurality of TRPs.

The specific random access information includes a Preamble code, a Root sequence, Preamble transmission power, PRACH time-frequency resources, a random access response window, a collision resolution timer, and the like.

Step 1302: multiple TRPs transmit the same specific random access information.

The specific random access information may be broadcast in the system information to the UE, or may be sent in an on-demand manner, i.e., sent through a dedicated signaling. The specific random access information may be used for either a contention random access or a non-contention random access procedure. For example, specific random access information for contention random access is broadcast in the system information, and specific random access information for non-contention random access is transmitted by the dedicated signaling. In addition, multiple TRPs need to be transmitted simultaneously.

Step 1303: and the UE acquires the same specific random access information sent by a plurality of TRPs and sends the Msg 1.

That is, after the UE randomly selects a certain Preamble code and a certain PRACH time-frequency resource indicated in the specific random access information, the Preamble code is sent on the PRACH time-frequency resource. Because a plurality of TRPs are synchronously transmitted, the UE is superposed with a plurality of synchronous signals when receiving, and the UE is favorable for accurately receiving the specific random access information.

For non-contention random access, the specific random access information corresponding to Msg1 is bound or mapped (mapping) with the UE identity, so contention resolution is not required.

To reduce access delay, the Msg1 may include UE identity information to simplify the random access procedure, for example, changing 4-step random access to 2-step random access.

Step 1304: after receiving the Msg1 sent by the UE, a plurality of TRPs adjacent to the UE send Msg2 in a random access response window.

The Msg2 includes parameters such as a backoff (backoff) parameter, a Preamble code corresponding to the Msg1, an uplink transmission timing advance (UL TA), an uplink resource (UL grant), and a temporary C-RNTI (for security).

The TRP uses the PDCCH to schedule the Msg2 and carries out addressing through RA-RNTI, wherein RA-RNTI is 1+ t _ id +10 f _ id, namely RA-RNTI is determined by the position of PRACH time frequency resources bearing the Msg 1.

There are two ways that a TRP sends Msg2 within a random access response window, one is an ideal forwarding/returning way between the TRP and the CU, and the other is a non-ideal forwarding/returning way between the TRP and the CU, as described in detail below.

One, ideal forward/backward transmission between TRP and CU.

1. And a plurality of TRPs send the Msg1 to the CU, and report the measurement information of the received Msg1, including the received signal strength, the signal quality and the like.

2. And the CU judges that the plurality of TRPs receive the Msg1 of the same UE through the same Preamble codes, PRACH time-frequency resources and the like in the plurality of Msg1, so that coordination processing is carried out, and the best TRP is selected to reply to the Msg2, or the plurality of TRPs of which the received signals meet the conditions reply to the same Msg 2.

Specifically, the TRP with the maximum received signal strength or the TRP with the best signal quality is selected according to the measurement information of the reported received Msg1, or a plurality of TRPs with received signal strength and signal quality meeting a preset threshold are selected. The TRP with a plurality of received signals satisfying the condition is selected to reply to the same Msg2 for reliable transmission. The preset threshold can be configured by CU or TRP.

3. One or more TRPs receive an indication from a CU to send Msg2, and send Msg2 within a random access response window.

Since the CU performs the coordination process, when a plurality of TRPs transmit Msg2, it can be a multipoint transmit diversity transmission, which corresponds to a Single Frequency Network (SFN) transmission. Specifically, multiple TRPs schedule Msg2 using PDCCH at the same time and are addressed by RA-RNTI, multiple TRPs schedule Msg2 on the same PDCCH resource (e.g., CCE), and the contents of the scheduled Msg2 are the same, i.e., the parameters included in Msg2 are the same. Or one TRP of the plurality of TRPs uses the PDCCH to schedule the Msg2, and the plurality of TRPs transmit the Msg2 with the same content on the same time-frequency resource at the same time.

And secondly, non-ideal forward/backward transmission is performed between the TRP and the CU.

Non-ideal forward/backward transmission between TRP and CU, so multiple TRP sends Msg2 without coordination by CU in order to reduce access latency. If the non-ideal forwarding/returning is the case of ideal delay and non-ideal throughput, CU coordinated Msg2 sending can be performed to simulate the operation of ideal forwarding/returning. The following is the operation in the case where the non-ideal fronthaul/backhaul delay is not ideal.

1. The CU allocates different uplink resources, temporary C-RNTIs (radio network temporary identities) for a plurality of TRPs (temporary random access messages) sending the same specific random access information in advance to ensure no conflict

2. After receiving the Msg1 sent by the UE, a plurality of TRPs respectively generate Msg2 with different contents, and send the Msg2 in a random access response window.

The uplink resources and the temporary C-RNTI contained in the Msg2 are different, the fallback parameters and the UL TA can be the same or different, and are the same as Preamble codes corresponding to the Msg1, and RA-RNTI used for addressing is the same. Further, a plurality of TRPs judge whether conditions are met according to the measurement information of the received Msg1, for example, whether the received signal strength and the signal quality meet preset thresholds, and the TRPs meeting the conditions reply to the Msg 2.

Without CU coordination, multiple TRPs may use PDCCH scheduling Msg2 at the same time, if it is a different PDCCH resource scheduling Msg2, the UE may receive multiple different Msg2 correctly, and if it is the same PDCCH resource scheduling Msg2, the UE may receive multiple different Msg2 correctly or may not resolve. This is because Msg2 is scheduled on the same PDCCH resource at the same time by a plurality of TRPs, and at the same time, the transmitted signals of a plurality of TRPs have the same strength and interfere with each other, and the probability that such an unresolved signal is extremely small, which is also a problem in the conventional LTE system.

In implementation, if the Msg1 includes UE identity information, the CU needs to obtain context (context) of the UE through the UE identity information, which requires interaction between the CU and the core network CN (e.g. authentication, etc. during initial access, or UE identification during handover), so multiple TRPs send Msg1 to the CU, and the CU sends Msg2 in coordination, which is similar to the operation of ideal forward/backward transmission and is not described herein again. Since the CU already identifies the UE through Msg1, the UE does not need to perform contention resolution.

Step 1305: and if the UE successfully receives one or more Msg2 in the random response window, the non-contention random access is completed.

And if the UE fails to receive, determining the time for initiating the next random access according to the backoff time delay parameter, and selecting the random access resource to initiate the next random access.

As shown in fig. 14, the method for contending for random access in the embodiment of the present invention includes:

step 1401 to step 1404 are the same as step 1301 to step 1304, and are not described herein again.

The difference is that in step 1403, for contention random access, multiple UEs may select the same Preamble code and different PRACH time-frequency resources; or different Preamble codes and the same PRACH time frequency resource can be selected.

Step 1405: the UE successfully receives one or more Msg2 within the random response window.

The situation of contention resolution by multiple UEs is similar to the existing LTE system. For example, UE1 and UE2 initiate contention random access, and the information of Msg1 and Msg2 is shown in the table below.

Step 1406: the UE sends Msg3 to one or more TRPs.

The Msg3 includes UE Identity information (e.g., InitialUE-Identity or ReestabUE-Identity) or C-RNTI of the UE.

If the UE receives one Msg2 within the random response window, then Msg3 is sent according to the information contained in Msg 2.

If the UE receives multiple msgs 2 for multiple TRP transmissions within a random response window, the UE may select one or more transmissions Msg 3.

Specifically, if UL TAs included in the multiple msgs 2 are different, the UE selects one UL TA to transmit one or more msgs 3. And if the UL grant and the temporary C-RNTI contained in the multiple Msg2 are different, the UE selects one or more groups of UL grant and temporary C-RNTI to send one or more Msg 3.

Further, the UE receives multiple Msg2 sent by multiple TRPs in the same subframe, and if the UL grant and the temporary C-RNTI are different, the UE sends Msg3 scrambled by different temporary C-RNTIs on different uplink resources in the same subframe.

Step 1407: one or more TRPs send measurement information of Msg3 and received Msg3 to a CU.

Since the Msg3 includes the UE identification information or the C-RNTI of the UE and needs to be processed by the CU, one or more TRPs send the Msg3 to the CU and report the measurement information of the received Msg3, including the received signal strength, the signal quality and the like.

Step 1408: and the CU identifies the UE through the UE identification information or the C-RNTI of the UE, carries out competition resolving judgment and carries out coordinated Msg4 sending.

Where Transmit Msg4 is similar to Transmit Msg2, namely the best TRP Transmit Msg4 or multiple TRPs meeting the conditions are selected to transmit the same Msg 4.

Specifically, if the UE indicated in the Msg3 sent by one or more TRPs is the same, the CU makes a contention resolution decision and performs coordinated Msg4 sending, and the Msg4 contains the contention resolution information of the UE;

if the UE indicated in the Msg3 sent by one or more TRPs is different, the CU makes a contention resolution decision and performs coordinated Msg4 sending, and the different Msg4 contains the contention resolution information of different UEs.

Step 1409: the TRP transmits the Msg4 containing the contention resolution information to the terminal according to the instruction of the CU.

Step 1410: after receiving the Msg4 containing the contention resolution information, the UE considers that the contention resolution is successful.

And if the UE does not receive the Msg4 when the contention resolution timer is overtime and the contention resolution is considered to be failed, determining the time for initiating the next random access according to the backoff time delay parameter, and selecting the random access resource to initiate the next random access.

The embodiments of the present invention will be described in detail below with reference to several examples.

The first embodiment is as follows: as shown in fig. 15, a diagram of random access under ideal fronthaul/backhaul of multiple TRP cells in accordance with an embodiment of the present invention.

Taking the non-contention random access process in the handover of the UE1 as an example, the specific process is as follows:

step 1: the UE1 switches between multiple TRP cells under CU management.

For example, the UE1 is handed over from a source Cell (TRP2 Cell2) to a target Cell (TRP3 Cell3 and/or TRP4 Cell 4). The CU will actively request the UE1 to initiate a non-contention random access procedure at handover.

Step 2: the CU instructs the TRP2 to send the non-contention specific random access information by proprietary signaling.

For example, Msg0 is sent through an RRC connection reconfiguration message, Msg0 includes a Preamble code and PRACH channel resources used by UE1 to initiate non-contention random access, and the specific random access information is bound or mapped with an identity of UE1 (e.g., C-RNTI of UE 1).

And step 3: the UE1 acquires the non-contention specific random access information sent by the TRP2 and sends Msg 1.

Since the specific random access information corresponding to the Msg1 is bound or mapped with the identity of the UE1, contention resolution is not required.

And 4, step 4: TRP3 and TRP4 adjacent to UE1 received Msg1 sent by UE 1.

Since the TRP and CU are ideally forward/backward, TRP3 and TRP4 send Msg1 to CU, and report measurement information of received Msg1, including received signal strength (e.g., received power RP), signal quality (e.g., SINR).

The CU judges that the TRP3 and the TRP4 receive the Msg1 of the same UE through the same Preamble code and PRACH time-frequency resource in the 2 Msg1, and identifies the UE1 through the binding or mapping relation between the specific random access information corresponding to the Msg1 and the identifier of the UE 1.

And the CU performs coordination processing, selects the TRP with the maximum received signal strength or the TRP with the best signal quality to reply to the Msg2 according to the measurement information of the reported received Msg1, for example, the received power of the TRP4 is greater than that of the TRP3, and selects the TRP4 to send the Msg 2.

TRP4 receives an indication from a CU to send Msg2 and sends Msg2 within the random access response window. The Msg2 includes parameters such as a backoff (backoff) parameter, a Preamble code corresponding to the Msg1, an uplink transmission timing advance (UL TA), an uplink resource (ULgrant), and a temporary C-RNTI. TRP4 schedules Msg2 using PDCCH and addresses via RA-RNTI.

And 5: the UE1 successfully receives an Msg2 in the random response window, and completes the non-contention random access process.

Example two: as shown in fig. 16, a diagram of random access under multiple TRP cell non-ideal fronthaul/backhaul in accordance with an embodiment of the present invention.

Taking the contention random access procedure in connection reestablishment of the UE2 as an example, the specific procedure is as follows:

step 1: the CU configures the same specific random access information for TRP1 cells to TRP4 cells under the management of the CU, wherein the specific random access information comprises Preamble codes, Root sequence, Preamble sending power, PRACH time frequency resources, a random access response window, a conflict resolution timer and the like.

Step 2: the TRP 1-TRP 4 synchronously transmit the same specific random access information in the system information for the contention random access.

And step 3: the UE2 has a Radio Link Failure (RLF) and initiates a connection re-establishment procedure.

The UE2 acquires the same specific random access information transmitted by a plurality of TRPs (e.g., TRP2, TRP3, and TRP4) and transmits Msg 1.

That is, after the UE2 randomly selects a certain Preamble code (e.g., Preamble1) and a certain PRACH time-frequency resource (e.g., PRACH1) indicated in the specific random access information, the Preamble1 is sent on the PRACH 1.

Since 3 TRPs are transmitted synchronously, UE2 is a superposition of multiple synchronization signals when receiving, which is beneficial for UE2 to accurately receive specific random access information.

And 4, step 4: TRP2, TRP3 and TRP4 adjacent to UE2 received Msg1 sent by UE 2.

Since there is non-ideal forward/backward transmission (non-ideal delay) between TRP and CU, 3 TRPs are sent Msg2 without coordination by CU in order to reduce access delay.

And the CU allocates different uplink resources and temporary C-RNTIs for TRP1 cells-TRP 4 cells which send the same specific random access information in advance, so as to ensure no conflict.

And 3 TRPs judge whether the conditions are met according to the measurement information of the received Msg1, for example, whether the received signal strength and the signal quality meet preset thresholds, and reply to the Msg2 by the TRPs meeting the conditions. The receiving power of TRP3 and TRP4 is greater than a preset threshold (configured by a CU), and the receiving power of TRP2 is less than the preset threshold, so that TRP3 and TRP4 respectively generate Msg2 with different contents, and send Msg2 in a random access response window, uplink resources and temporary C-RNTIs contained in the Msg2 are different, backoff parameters are different, UL TAs are the same (UE2 is closer to TRP3 and TRP4), UL TAs are the same as Preamble codes corresponding to the Msg1, and RA-RNTIs used for addressing are the same.

Since there is no CU coordination, TRP3 and TRP4 schedule Msg2 using different PDCCH resources at the same time.

And 5: the UE2 successfully received 2 Msg2 within the random response window.

Step 6: since the UE2 receives 2 Msg2 sent by 2 TRPs in the same subframe, where the UL grant and the temporary C-RNTI are different, the UE2 sends Msg3 scrambled by different temporary C-RNTIs on different uplink resources in the same subframe, and the Msg3 includes identification information (e.g., reesabue-Identity 1) of the UE 2.

And 7: since the Msg3 includes the identification information of the UE2 and requires processing by the CU, the TRP3 and TRP4 send 2 msgs 3 to the CU and report measurement information of the received Msg3, including received signal strength, signal quality, and the like.

And the CU identifies the UE2 through the identification information of the UE2, judges that the UE indicated in the Msg3 sent by the 2 TRPs is the same, carries out competition resolving judgment, and selects the TRP4 with the largest RP to send the Msg 4.

TRP4 receives an indication from CU to send Msg4, and sends Msg4 before the conflict resolution timer expires, and Msg4 includes contention resolution information of UE 2.

And 8: the UE2 receives the Msg4 before the collision resolution timer expires, wherein the Msg4 includes the contention resolution information of the UE2, and the UE2 considers that the contention resolution is successful, and completes the contention random access procedure.

Example three: as shown in fig. 17, a diagram of random access under ideal forward transmission/return of a virtual cell according to an embodiment of the present invention is shown.

Taking the simplified random access process in the uplink/downlink data arrival of the UE3 as an example, the specific working flow is as follows:

step 1: the virtual cell under the management of the CU comprises TRP 1-TRP 4, and the CU configures the same specific random access information for 4 TRP, wherein the specific random access information comprises Preamble codes, Root sequence, Preamble sending power, PRACH time frequency resources, a random access response window, a conflict resolution timer and the like.

And step 3: the UE3 is an inactive (inactive state) UE in connected mode (connected mode). When the UE3 has uplink/downlink data to arrive, a simplified random access procedure is initiated, that is, the Msg1 includes the UE identity, so that the 4-step random access procedure can be simplified into 2 steps (only Msg1 and Msg2 are needed).

The UE3 obtains the same specific random access information sent by multiple TRPs (e.g., TRP2, TRP3, and TRP4), and sends Msg1, that is, after the UE3 randomly selects a certain Preamble code (e.g., Preamble2) and a certain time-frequency PRACH resource (e.g., PRACH2) indicated in the specific random access information, the Preamble2 is sent on the PRACH 2.

Since 3 TRPs are transmitted synchronously, UE3 is a superposition of multiple synchronization signals when receiving, which is beneficial for UE3 to accurately receive specific random access information. In order to reduce access delay and simplify the random access process, the Msg1 of the UE3 includes identification information of the UE3 (e.g., C-RNTI of the UE 3).

And 4, step 4: TRP2, TRP3 and TRP4 adjacent to UE3 received Msg1 sent by UE 3.

Since TRP and CU are ideally forward/backward, TRP2, TRP3 and TRP4 send Msg1 to CU, and report measurement information of received Msg1 including received signal strength (e.g., received power RP), signal quality (e.g., SINR).

The CU recognizes the UE3 through the identification information of the UE3, and judges that the UE indicated in the Msg1 sent by 3 TRPs is the same.

The CU performs coordination processing, and selects a plurality of TRPs with received signal strength or signal quality meeting a preset threshold according to the measurement information of the reported received Msg1 to reply to the same Msg2, for example, the SINR of the TRP3 and the TRP4 is greater than the preset threshold (configured by the CU), while the SINR of the TRP2 is less than the preset threshold, so that the CU selects the TRP3 and the TRP4 to send the same Msg2 for reliable transmission.

TRP3 and TRP4 receive an indication from a CU to send Msg2, send the same Msg2 within the random access response window, and are multicast diversity transmissions. Specifically, TRP3 and TRP4 schedule Msg2 using PDCCH at the same time and address with C-RNTI, 2 TRPs schedule Msg2 on the same PDCCH resource (e.g. CCE), and the content of the scheduled Msg2 is the same, i.e. the parameters contained in Msg2 are the same. Or the TRP4 uses PDCCH to schedule Msg2, TRP3 and TRP4 to send Msg2 with the same content on the same time-frequency resource at the same time. The Msg2 includes parameters such as backoff (backoff) parameters, Preamble codes corresponding to the Msg1, uplink transmission timing advance (UL TA), and uplink resources (UL grant).

And 5: the UE3 successfully receives one Msg2 within the random response window.

Since TRP3 and TRP4 schedule Msg2 with the PDCCH scrambled with the C-RNTI, UE3 completes the simplified random access procedure upon receiving the scheduling command.

Example four: as shown in fig. 18, a schematic diagram of random access under non-ideal fronthaul/backhaul of a virtual cell according to an embodiment of the present invention.

Taking the contention random access process in the initial access of UE4 and UE5 as an example, the specific work flow is as follows:

And step 3: the UE4 and the UE5 initially access and initiate a competition random access process. The UE4 and the UE5 acquire the same specific random access information sent by a plurality of TRPs (such as TRP2, TRP3 and TRP4) and send Msg 1.

That is, after the UE4 and the UE5 randomly select a certain Preamble code indicated in the specific random access information (for example, both the UE4 and the UE5 select Preamble3) and a certain PRACH time-frequency resource (for example, the UE4 selects PRACH3, and the UE5 selects PRACH4), the UE4 sends a Preamble3 on the PRACH3, and the UE5 sends a Preamble3 on the PRACH 4.

Since 3 TRPs are transmitted synchronously, UE4 and UE5 are superimposed when receiving multiple synchronization signals, which is beneficial for UE4 and UE5 to accurately receive specific random access information.

And 4, step 4: TRP2 and TRP3 adjacent to UE4 received Msg1 sent by UE4, and TRP3 and TRP4 adjacent to UE5 received Msg1 sent by UE 5.

And the CU allocates different uplink resources and temporary C-RNTIs for the TRPs 1-4 which send the same specific random access information in the virtual cell in advance, so as to ensure no conflict.

And 3 TRPs judge whether the conditions are met according to the measurement information of the received Msg1, for example, whether the received signal strength and the signal quality meet preset thresholds, and reply to the Msg2 by the TRPs meeting the conditions. Wherein, RP of TRP2 and TRP3 is greater than a preset threshold (configured by CU), therefore, TRP2 and TRP3 each generate Msg2 with different content, and Msg2 and Msg2 are sent in a random access response window, uplink resources and temporary C-RNTIs contained in Msg2 are different, backoff parameters are different, UL TA is the same (UE4 is closer to TRP2 and TRP 3), Preamble code corresponding to Msg1 is the same (e.g. Preamble3), and RA-RNTI for addressing is the same (e.g. RA-1, RA-RNTI1 is determined by PRACH 3).

Similarly, the RP of TRP3 and TRP4 is greater than the preset threshold (configured by CU), so TRP3 and TRP4 each generate Msg2 with different content, and Msg2 is sent in the random access response window, the uplink resources and temporary C-RNTIs contained in Msg2 are different, the backoff parameters are different, the UL TA is the same (UE5 is closer to TRP3 and TRP4), the Preamble code corresponding to Msg1 is the same (e.g., Preamble3), and the RA-RNTI for addressing is the same (e.g., RA-2, RA-RNTI2 is determined by PRACH 4).

Since there is no CU coordination, TRP2 and TRP3 use different PDCCH resource schedules Msg2 at different times, TRP3 and TRP4 use different PDCCH resource schedules Msg2 at the same time.

And 5: UE4 successfully received 2 Msg2 within the random response window, and UE5 successfully received 2 Msg2 within the random response window.

Step 6: since UE4 received 2 Msg2 for 2 TRP transmissions in different subframes.

Wherein the UL grant is different from the temporary C-RNTI, the UE4 selects 1 Msg2 (e.g., Msg2 sent by TRP 2) received first, and sends 1 Msg3 on the uplink resource, and the Msg3 includes identification information of the UE4 (e.g., initial UE-Identity 1).

Since the UE5 receives 2 Msg2 sent by 2 TRPs in the same subframe, where UL grant and temporary C-RNTI are different, the UE5 sends Msg3 scrambled by different temporary C-RNTIs on different uplink resources in the same subframe, and the Msg3 includes identification information (e.g., InitialUE-Identity2) of the UE 5.

And 7: since the Msg3 includes the identification information of the UE4 and requires the CU to process, the TRP2 transmits Msg3 to the CU.

The CU identifies the UE4 through the identification information of the UE4, makes a contention resolution decision, and selects TRP2 to send Msg 4.

Similarly, since the Msg3 includes the identification information of the UE5 and requires processing by the CU, the TRP3 and the TRP4 send 2 msgs 3 to the CU, and report measurement information of the received Msg3, including received signal strength, signal quality, and the like.

And the CU identifies the UE5 through the identification information of the UE5, judges that the UE indicated in the Msg3 sent by the 2 TRPs is the same, carries out competition resolving judgment, and selects the TRP4 with the maximum SINR to send the Msg 4.

TRP2 receives an indication from CU to send Msg4, and sends Msg4 before the conflict resolution timer expires, and Msg4 includes contention resolution information of UE 4. Similarly, TRP4 receives an instruction from CU to send Msg4, and sends Msg4 before the conflict resolution timer expires, wherein the Msg4 includes the contention resolution information of UE 5.

And 8: and the UE4 and the UE5 receive the Msg4 before the conflict resolution timer is overtime, wherein the Msg4 contains the competition resolution information of the UE4 and the UE5, and the UE4 and the UE5 consider that the competition resolution is successful and complete the competition random access process.

The present application is described above with reference to block diagrams and/or flowchart illustrations of methods, apparatus (systems) and/or computer program products according to embodiments of the application. It will be understood that one block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, 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, and/or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer and/or other programmable data processing apparatus, create means for implementing the functions/acts specified in the block diagrams and/or flowchart block or blocks.

Accordingly, the subject application may also be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.). Furthermore, the present application may take the form of a computer program product on a computer-usable or computer-readable storage medium having computer-usable or computer-readable program code embodied in the medium for use by or in connection with an instruction execution system. In the context of this application, a computer-usable or computer-readable medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A method for performing random access, the method comprising:

the network side equipment sends the specific random access information to a terminal so that the terminal can access through the random access information;

the network side device sends the specific random access information to a terminal, and the method comprises the following steps:

the network side equipment sends the specific random access information to a terminal through broadcasting or special signaling;

the network side device determining the same random access information as a plurality of other network side devices includes:

the network side equipment receives the specific random access information from the control equipment;

after the network side device sends the specific random access information to the terminal, the method further includes:

the network side equipment receives a first message which is sent by the terminal and contains a Preamble code in the random access information;

the network side equipment sends a second message containing random access response information in a random access response window;

after the network side device receives the first message which is sent by the terminal and contains the preamble in the random access information, and before the network side device sends the second message which contains the random access response information in the random access response window, the method further includes:

the network side equipment reports the first message to the control equipment and determines to receive a first sending instruction of the control equipment;

wherein the control device notifies the first transmission instruction to a plurality of the network-side devices;

the network side equipment and other network side equipment receiving the first sending instruction use a Physical Downlink Control Channel (PDCCH) to schedule the second message at the same time, and address the second message through a random access-radio network temporary identifier (RA-RNTI);

the network side device sends a second message containing random access response information in a random access response window, and the second message comprises:

2. The method according to claim 1, wherein the control device notifies a plurality of the network-side devices of the first transmission instruction;

3. The method of claim 1, wherein the network side device sends the second message containing the random access response information in a random access response window, comprising:

4. The method of claim 3, wherein before the network side device sends the second message containing the random access response information in the random access response window, the method further comprises:

5. The method according to any one of claims 1 to 4, wherein after the network side device sends the second message including the random access response information in the random access response window, the method further includes:

6. A method for performing random access, the method comprising:

the control equipment determines specific random access information;

the control equipment sends the specific random access information to a plurality of network side equipment, so that the plurality of network side equipment send the specific random access information to a terminal through broadcasting or special signaling, and the terminal accesses through the random access information; and after transmitting the specific random access information to the terminal: receiving a first message which is sent by the terminal and contains a Preamble code in the random access information, and sending a second message which contains random access response information in a random access response window;

after the network side device receives a first message which is sent by the terminal and contains a lead code in the random access information, and before a second message which contains the random access response information is sent in a random access response window, the control device receives the first message reported by the network side device, determines a first sending instruction, and sends the first sending instruction to the network side device;

wherein the control device notifies the first transmission instruction to a plurality of the network-side devices; before the network side equipment sends a second message containing random access response information in a random access response window, the network side equipment uses a Physical Downlink Control Channel (PDCCH) to schedule the second message at the same time as other network side equipment receiving the first sending instruction, and addresses the second message through a random access-radio network temporary identifier (RA-RNTI); the network side device sends a second message containing random access response information in a random access response window, and the second message comprises: and the network side equipment and other network side equipment receiving the first sending instruction send second messages containing the same random access response information.

7. The method of claim 6, wherein after the control device transmits the specific random access information to a plurality of network-side devices, the method further comprises:

8. The method of claim 7, wherein the controlling device selecting at least one network-side device from the plurality of network-side devices comprises:

9. The method of claim 6, wherein the method further comprises:

10. The method according to any one of claims 6 to 9, wherein after the controlling device sends the specific random access information to a plurality of network-side devices, the method further comprises:

11. The method according to any of claims 6 to 9, wherein the specific random access information includes but is not limited to some or all of the following information:

the system comprises a lead code, a Root sequence, lead code sending power, PRACH time frequency resources, a random access response window and a conflict resolution timer.

12. A method for performing random access, the method comprising:

the terminal carries out random access according to the specific random access information;

the specific random access information is sent by the network side equipment through broadcasting or special signaling;

wherein, the terminal performs random access according to the specific random access information, including:

the terminal receives a second message which is sent by at least one network side device and contains the same random access response information, wherein the second message is sent by the network side device in a random access response window; after the network side device receives a first message which is sent by the terminal and contains a lead code in the random access information, the network side device reports the first message to a control device before sending a second message which contains the random access response information in a random access response window, and determines to receive a first sending instruction of the control device; wherein the control device notifies the first transmission instruction to a plurality of the network-side devices; before the network side equipment sends a second message containing random access response information in a random access response window, the network side equipment and other network side equipment receiving the first sending instruction use a Physical Downlink Control Channel (PDCCH) to schedule the second message at the same time, and address the second message through a random access-radio network temporary identifier (RA-RNTI);

the network side device sends a second message containing random access response information in a random access response window, and the second message comprises: and the network side equipment and other network side equipment receiving the first sending instruction send second messages containing the same random access response information.

13. The method of claim 12, wherein the terminal places a preamble bound to the terminal in the specific random access information in the first message.

14. The method of claim 13, wherein the terminal places a terminal identification in the first message.

15. The method of claim 13, wherein after the terminal receives a second message containing the same random access response information sent by at least one of the network-side devices, the method further comprises:

16. The method of claim 15, wherein the terminal receives a plurality of second messages; the terminal sends a third message containing competition information to at least one network side device sending the second message, and the third message comprises:

17. The method of claim 16, wherein the terminal transmits a third message including contention information according to the selected UL grant and the temporary C-RNTI, comprising:

18. A network side device for performing random access, the network side device comprising:

the first processing module is used for sending the specific random access information to a terminal so that the terminal can access through the random access information;

the first processing module is specifically configured to: transmitting the specific random access information to a terminal through broadcasting or dedicated signaling;

the first information determination module is specifically configured to: receiving the specific random access information from a control device;

the first processing module is further configured to: after the specific random access information is sent to a terminal, receiving a first message which is sent by the terminal and contains a Preamble code in the random access information; sending a second message containing random access response information in a random access response window;

the first processing module is specifically configured to: reporting the first message to the control equipment, and after determining that a first sending instruction of the control equipment is received, sending a second message containing random access response information in a random access response window;

the control device notifies the first sending instruction to a plurality of network side devices;

the first processing module is specifically configured to: the second message is scheduled by using a Physical Downlink Control Channel (PDCCH) at the same time as other network side equipment receiving the first sending instruction, and is addressed through an RA-RNTI; and sending a second message containing the same random access response information with other network side equipment receiving the first sending instruction.

19. The network-side device of claim 18, wherein the control device notifies a plurality of the network-side devices of the first transmission indication;

the first processing module is specifically configured to:

20. The network-side device of claim 18, wherein the first processing module is specifically configured to:

21. The network-side device of claim 20, wherein the first processing module is further configured to:

22. The network-side device of any one of claims 18 to 21, wherein the first processing module is further configured to:

23. A control apparatus for performing random access, comprising:

a second processing module, configured to send the specific random access information to multiple network-side devices, so that the multiple network-side devices send the specific random access information to a terminal through broadcast or dedicated signaling, and the terminal performs access through the random access information; and after transmitting the specific random access information to the terminal: receiving a first message which is sent by the terminal and contains a Preamble code in the random access information, and sending a second message which contains random access response information in a random access response window;

the second processing module is further configured to receive the first message reported by the network side device, determine a first sending instruction, and send the first sending instruction to the network side device;

the second processing module is configured to notify the first sending instruction to the plurality of network-side devices; before the network side equipment sends a second message containing random access response information in a random access response window, the network side equipment uses a Physical Downlink Control Channel (PDCCH) to schedule the second message at the same time as other network side equipment receiving the first sending instruction, and addresses the second message through a random access-radio network temporary identifier (RA-RNTI); the network side device sends a second message containing random access response information in a random access response window, and the second message comprises: and the network side equipment and other network side equipment receiving the first sending instruction send second messages containing the same random access response information.

24. The control device of claim 23, wherein the second processing module is further to:

25. The control device of claim 24, wherein the second processing module is specifically configured to:

26. The control device of claim 23, wherein the second processing module is further to:

27. The control device of any of claims 23 to 26, wherein the second processing module is further configured to:

28. The control device according to any of claims 23 to 26, wherein the specific random access information includes but is not limited to some or all of the following information:

29. A terminal for performing random access, the terminal comprising:

the access module is used for carrying out random access according to the specific random access information;

wherein the access module is specifically configured to:

sending a first message containing a lead code in the specific random access information to part or all of the network side equipment in the plurality of network side equipment through a time-frequency resource in the specific random access information; receiving a second message which is sent by at least one network side device and contains the same random access response information; the second message is sent by the network side equipment in a random access response window; after the network side device receives a first message which is sent by the terminal and contains a lead code in the random access information, the network side device reports the first message to a control device before sending a second message which contains the random access response information in a random access response window, and determines to receive a first sending instruction of the control device; wherein the control device notifies the first transmission instruction to a plurality of the network-side devices; before the network side equipment sends a second message containing random access response information in a random access response window, the network side equipment and other network side equipment receiving the first sending instruction use a Physical Downlink Control Channel (PDCCH) to schedule the second message at the same time, and address the second message through a random access-radio network temporary identifier (RA-RNTI);

30. The terminal of claim 29, wherein the access module is further configured to:

31. The terminal of claim 30, wherein the access module is further configured to:

placing a terminal identification in the first message.

32. The terminal of claim 30, wherein the access module is further configured to:

33. The terminal of claim 32, wherein the receiving module receives a plurality of second messages;

the access module is specifically configured to:

34. The terminal of claim 33, wherein the access module is specifically configured to: