CN114554572B

CN114554572B - Terminal access method and network equipment deployment method in far-end scene

Info

Publication number: CN114554572B
Application number: CN202210449115.3A
Authority: CN
Inventors: 林力; 陈瑞欣; 宋怡昕
Original assignee: Guangzhou Shiju Network Technology Co Ltd
Current assignee: Guangdong Shiju Network Technology Co ltd
Priority date: 2022-04-27
Filing date: 2022-04-27
Publication date: 2022-08-05
Anticipated expiration: 2042-04-27
Also published as: CN114554572A

Abstract

The application discloses a terminal access method and a network equipment deployment method in a far-end scene. The method comprises the following steps: a terminal receives broadcast information sent by network equipment; the terminal measures the received signal strength of the network equipment; when the received signal strength obtained by comparison and measurement exceeds a first judgment threshold, the terminal continuously sends PRACH carrying Preamble information to the network equipment and transmits PUSCH carrying RRC information to the network equipment according to the sequence; the network equipment receives and decodes the Preamble message, obtains a Preamble signal index and a time delay estimation value between the terminal and the network equipment, and determines time delay compensation according to the time delay estimation value between the terminal and the network equipment; the network equipment receives a time domain signal containing a PUSCH according to the time delay compensation calibration, decodes the load and processes the borne RRC message; and the network equipment returns an access response to the terminal according to the processing result. The method can enable the terminal with longer distance to start the two-step access process, thereby improving the efficiency of remote terminal access.

Description

Terminal access method and network equipment deployment method in far-end scene

Technical Field

The present application relates to the field of mobile communications technologies, and in particular, to a terminal access method and a network device deployment method in a remote scenario.

Background

In a 5G wireless NR (New Radio, New air interface) Radio specification introduced by a 3GPP R16 standard, for a delay-sensitive service, in order to shorten a terminal Access time, a two-step Random Access (2-step RACH) method is introduced on the basis of a four-step Random Access Channel (4-step RACH) method of a basic specification.

Fig. 1 is a schematic diagram of a four-step random access method. As shown in fig. 1, the method mainly comprises four steps:

msg 1: when a terminal (UE, User Equipment, i.e., terminal) has data to send, first, according to Random Access resource information configured by the system, wait for an RACH scheduling period, select a Preamble and send a message Msg1 carrying the Preamble to a gNB (5G base station) through PRACH (Physical Random Access Channel) resources.

Msg 2: after receiving the Msg1 sent by the terminal, the base station returns a random access response message Msg2 to the terminal, and one Msg2 can respond to random access requests of a plurality of terminals.

Msg 3: after receiving the Msg2, the terminal sends Msg3 on a PUSCH (Physical Uplink Shared Channel) resource allocated by Msg2, and Msg3 includes different contents for different scenes. At the time of initial access, the Msg3 carries an RRC connection request message generated by an RRC (Radio Resource Control) layer.

Msg 4: and the base station and the terminal finish final competition resolution through the message Msg4, the terminal judges whether random access is successful according to the Msg4, and the Msg4 content corresponds to the Msg3 content.

Fig. 2 is a schematic diagram of a two-step random access method. As shown in fig. 2, the method mainly includes two steps:

MSGA: the terminal sends the MSGA to the base station. The MSGA includes Preamble transmission on PRACH and data transmission on PUSCH, and may be understood as Msg1 plus Msg3 of 4-step RACH.

MSGB: and after receiving the MSGA sent by the terminal, the base station returns the MSGB to the terminal. The MSGB includes a random access response message and a contention resolution flag, which can be understood as Msg2 plus Msg4 in 4-step RACH.

Fig. 3 is a reference diagram of the time domain structure of the MSGA. As shown in fig. 3, the MSGA is composed of a PRACH Preamble (Preamble) sent by the terminal in sequence and a PUSCH for carrying RRC signaling (different according to different access scenarios). In the MSGA, a resource for transmitting a preamble signal is referred to as a PRACH opportunity (RO), and a resource for transmitting a PUSCH is referred to as a PUSCH Opportunity (PO), and they are associated with each other according to the configuration of a higher layer signaling. The PO can be configured with a number of resources: in the time domain, multiple POs may be multiplexed in a time slot, time-division multiplexing (TDM); in the Frequency domain, multiple POs may be multiplexed on different sets of RBs (Resource blocks), i.e., Frequency-division multiplexing (FDM).

Through the two-step random access method, the terminal and the base station can complete access in two information exchange processes. However, one of the key technical problems faced by the two-step random access method is: when the terminal transmits the PUSCH of the MSGA, an adjustment command for a Timing Advance (TA) is not obtained in Advance from the Msg2 as in the four-step random access method. The value of TA is calculated and obtained by the base station according to the reception of the PRACH preamble, and reflects the Round Trip Time (RTT) caused by the wireless propagation distance between the terminal and the base station.

Fig. 4 is a schematic diagram illustrating the effect of time delay on an uplink signal. As shown in fig. 4, since the PUSCH of the MSGA is not time-advanced to align the time reference of the uplink signal, if the delay, that is, the RTT, exceeds the guard length of the Cyclic Prefix (CP) of the OFDM (Orthogonal Frequency Division Multiplexing) signal, the signal cannot be successfully decoded. In the prior art specification, a small delay is determined as a prerequisite for enabling a two-step access. The system assists in judging the distance between the terminal and the base station by setting a Reference Signal Receiving Power (RSRP) threshold: if the RSRP measured by the terminal exceeds the threshold, the terminal is close to the base station, the RTT is small, the PUSCH can be normally decoded even without TA adjustment, and two-step access can be adopted; otherwise, the RTT is larger, the time delay of the PUSCH exceeds the protection range of the CP, and only four-step access can be adopted.

However, two-step access is generated by the delay-sensitive service requirement, and a terminal far away from the base station also has a requirement of fast access. The prior art cannot solve the problem of quick access of a terminal in a far-end scene.

The application considers the requirement of applying two-step access in a far-end scene, provides a new MSGA transmission processing method, and enables a terminal with a longer distance to start a two-step access process.

Disclosure of Invention

In view of this, it is necessary to provide a method for accessing a base station by a terminal in a remote scenario and a base station deployment method, so as to solve the technical problem in the prior art that a terminal cannot be accessed quickly by a two-step random access method, but only depends on a four-step random access (4-step RACH) method in the remote scenario.

In order to achieve the above object, the present application provides a method for a terminal to access a base station in a remote scenario, comprising the following steps:

a terminal receives broadcast information sent by network equipment, wherein the broadcast information comprises a first judgment threshold value, first resource allocation information used for indicating a terminal PUSCH time domain resource allocation mode and second resource allocation information used for indicating a terminal PUSCH resource multiplexing mode;

the terminal measures the received signal strength of the network equipment and compares the measured received signal strength with a first judgment threshold;

when the measured received signal strength exceeds a first judgment threshold, the terminal continuously sends PRACH carrying Preamble information to the network equipment according to the sequence, and transmits PUSCH carrying RRC information to the network equipment according to the first resource allocation information and the second resource allocation information;

the network equipment receives and decodes the Preamble message, obtains a Preamble signal index and a time delay estimation value between the terminal and the network equipment, and determines time delay compensation according to the time delay estimation value between the terminal and the network equipment;

the network equipment receives a time domain signal containing a PUSCH according to the time delay compensation calibration, decodes the load and processes the borne RRC message;

and the network equipment returns an access response to the terminal according to the processing result.

Further, in a preferred embodiment provided by the present application, the first resource allocation information includes a first PUSCH time domain resource allocation index, where the first PUSCH time domain resource allocation index is used to determine an OFDM symbol resource used by a PUSCH in a configured first PUSCH time domain resource allocation list, so that a tail symbol of the OFDM symbol resource is reserved, and a symbol set time length of the tail reserved is at least equal to a CP length of a PRACH preamble.

Further, in a preferred embodiment provided by the present application, the second resource allocation information includes a second PUSCH resource multiplexing indication factor, where the second PUSCH resource multiplexing indication factor is used to select an adopted resource multiplexing mode under the condition that the total number of POs is constant, so as to maximize the number of POs adopting frequency division multiplexing.

Further, in a preferred embodiment provided by the present application, the network device receives and decodes the Preamble message, obtains a Preamble index and a delay estimation value between the terminal and the network device, and determines the delay compensation according to the delay estimation value between the terminal and the network device, which specifically includes:

when the time delay estimation value between the terminal and the network equipment is smaller than or equal to a second judgment threshold value, determining that the time delay compensation is 0;

when the time delay estimation value between the terminal and the network equipment is larger than a second judgment threshold value, taking the time delay estimation value between the terminal and the network equipment as time delay compensation;

wherein the second judgment threshold does not exceed the time length occupied by the CP of one PUSCH at most.

Further, in a preferred embodiment provided in the present application, when there are multiple terminals sending PRACH carrying Preamble messages to a network device in a same transmission opportunity of the PRACH, the network device receives and decodes the Preamble messages, obtains a Preamble index and a delay estimation value between the terminal and the network device, and determines a delay compensation according to the delay estimation value between the terminal and the network device, further including:

and the network equipment takes the time delay estimation values between the plurality of terminals and the network equipment as elements, and determines the minimum value of the time delay estimation values between the plurality of terminals and the network equipment, which correspond to the plurality of elements with the difference values between the elements within the range of the second judgment threshold, for the plurality of terminals corresponding to the plurality of elements larger than the second judgment threshold.

The application also provides a terminal access method under the far-end scene, which comprises the following steps at the network equipment side:

a wireless module of network equipment sends broadcast information to a terminal, wherein the broadcast information comprises a first judgment threshold value, first resource allocation information used for indicating a terminal PUSCH time domain resource allocation mode and second resource allocation information used for indicating a terminal PUSCH resource multiplexing mode;

the wireless module of the network device receives:

the terminal continuously sends PRACH carrying Preamble information to the network equipment according to the sequence, and transmits PUSCH carrying RRC information to the network equipment according to the first resource allocation information and the second resource allocation information;

a wireless module of the network equipment converts the received Preamble into a frequency domain signal;

the wireless module of the network equipment sends the frequency domain signal of the Preamble to a data module of the network equipment;

a data module of the network equipment decodes the Preamble to obtain a time delay estimation value between the terminal and the network equipment, and determines time delay compensation according to the time delay estimation value between the terminal and the network equipment;

a data module of the network equipment sends the time delay compensation and the PUSCH identification associated with the time delay compensation to a wireless module of a base station;

the wireless module of the network equipment calibrates and receives a time domain signal which is associated with the time delay compensation and contains a PUSCH (physical uplink shared channel) according to the time delay compensation, converts the time domain signal into a frequency domain signal and sends the frequency domain signal to the data module of the network equipment;

the data module of the network equipment decodes the PUSCH according to the frequency domain signal and processes the RRC message carried by the PUSCH;

Further, in a preferred embodiment provided by the present application, the decoding, by a data module of the network device, the Preamble to obtain a delay estimation value between the terminal and the network device, and determining the delay compensation according to the delay estimation value between the terminal and the network device specifically includes:

Further, in a preferred embodiment provided by the present application, when there are multiple terminals sending PRACH carrying Preamble messages to a network device in the same transmission time of the PRACH, a data module of the network device decodes the Preamble to obtain a delay estimation value between the terminal and the network device, and determines a delay compensation according to the delay estimation value between the terminal and the network device, including:

The application also provides a network equipment deployment method, which is suitable for terminal access in a far-end scene and is characterized in that:

the time-frequency domain serial-parallel conversion function of the network equipment is deployed in a wireless module of a base station;

the network device processing function is deployed in a data module of the base station.

Compared with the prior art, the terminal access method under the far-end scene provided by the embodiment of the application determines the time delay compensation of the PUSCH receiving in the MSGA by the network equipment according to the preamble signal index and the time delay estimation value between the terminal and the network equipment for the terminal under the far-end scene, dynamically adjusts the signal extraction of the PUSCH of the MSGA, realizes the successful receiving of the PUSCH under the large time delay, enlarges the application range of two-step random access under the distance condition, and improves the terminal access efficiency under the far-end scene.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

fig. 1 is a schematic diagram of a four-step random access method in the background art.

Fig. 2 is a diagram of a two-step random access method in the background art.

Fig. 3 is a reference diagram of the MSGA time domain structure in the background art.

Fig. 4 is a schematic diagram illustrating an influence of a delay on an uplink signal in the background art.

Fig. 5 is a flowchart illustrating a terminal access method in a remote scenario according to the present application.

Fig. 6 is a schematic diagram of receiving, by a network device, an uplink signal after compensating for a delay according to TA in the present application.

Fig. 7 is a schematic diagram of a method for selecting a calibration timeslot according to compensated delay in the present application.

Fig. 8 is a schematic diagram of a method for adjusting time domain resource allocation to avoid interference caused by an excessive time delay in the present application.

Fig. 9 is a schematic diagram of multiplexing configuration of PUSCH occasions in the present application.

Fig. 10 is a schematic diagram of a combining method for compensating delay from PRACH detection delay to PUSCH in the present application.

Fig. 11 is a schematic flowchart of a network device side of a method for terminal access in a remote context in the present application.

Fig. 12 is a schematic diagram of a network device deployment method in the present application.

Fig. 13 is a schematic diagram of a low physical layer processing flow of a radio module gNB-RU incorporating time alignment in the present application.

The implementation, functional features and advantages of the objectives of the present application will be further explained with reference to the accompanying drawings.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It is to be understood that the embodiments described are only a few embodiments of the present application and not all 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 application.

The embodiments of the present application have been described with reference to a terminal device and a network device. Wherein:

a terminal device may also be referred to as a User Equipment (UE), an access terminal, a subscriber unit, a mobile station, a remote terminal, a mobile device, a User terminal, a wireless communication device, a User agent, or a User Equipment, etc.

By way of example and not limitation, in the embodiments of the present application, the terminal device may also be a wearable device. For example: smart watches or smart glasses and the like, and only focus on a certain type of application functions, and need to be used in cooperation with other devices such as smart phones, such as various smart bracelets for physical sign monitoring, smart jewelry and the like.

The network device may be a device for communicating with a mobile device, such as a network device in an NR network or a base station (gNB) or a network device in a future evolved wireless network, etc.

In this embodiment of the present application, a network device provides a service for a cell, and a terminal device communicates with the network device through a transmission resource (e.g., a frequency domain and a spectrum resource) used by the cell, where the cell may be a cell corresponding to the network device (e.g., a base station), and the cell may belong to a macro base station or a base station corresponding to a Small cell (Small cell). Here, the small cell may include: urban cells (Metro cells), Micro cells (Micro cells), Pico cells (Pico cells), Femto cells (Femto cells), and the like.

The embodiments of the present application will be described in further detail with reference to the drawings attached hereto. In the drawings and embodiments of the present application, a terminal device is exemplified by a terminal (UE), and a network device is exemplified by a 5G base station (gNB). It is to be understood that the embodiments described herein are merely illustrative and explanatory of the application and are not restrictive thereof.

Referring to fig. 5, the present application discloses a terminal access method in a remote scenario, including:

step S101: the terminal receives broadcast information sent by network equipment, wherein the broadcast information comprises a first judgment threshold value, first resource allocation information used for indicating a terminal PUSCH time domain resource allocation mode and second resource allocation information used for indicating a terminal PUSCH resource multiplexing mode.

In the embodiment of the application, the network device (gNB) sends broadcast information to the terminal (UE) in the cell, wherein the broadcast information comprises a first judgment threshold value, first resource allocation information used for indicating a PUSCH time domain resource allocation mode of the terminal (UE) and second resource allocation information used for indicating a PUSCH resource multiplexing mode of the terminal (UE). Indicating a mode (two steps or four steps) adopted by a terminal (UE) to access through a first judgment threshold; and indicating the terminal (UE) by the first resource allocation information in which way to configure the PUSCH time domain resource, and indicating the terminal (UE) by the second resource allocation information in which way to configure the PUSCH resource multiplexing way. The broadcast information can be sent based on the related communication protocol and data message format in the prior art, by defining the related RRC system parameters, or by self-defining the protocol and message format.

A terminal (UE) receives broadcast information transmitted from a local intra-cell network device (gNB).

Step S102: the terminal measures the received signal strength of the network equipment, and compares the measured received signal strength with a first judgment threshold value.

In an embodiment of the application, a terminal (UE) determines the received Signal strength of a network device (gNB) by measuring a Reference Signal Receiving Power (RSRP) of the network device (gNB). RSRP is one of the key parameters representing wireless signal strength and physical layer measurement requirements in LTE and NR networks, and is the average of the received signal power over all Resource Elements (REs) carrying reference signals within a certain symbol. Within the range of the current cell, the distance between the terminal (UE) and the network equipment (gNB) can be judged according to the RSRP.

Specifically, according to the comparison between the received signal strength and the first determination threshold, it may be determined whether the distance between the terminal (UE) and the network device (gNB) is within a preset range, and further, it is determined whether the time delay between the terminal (UE) and the network device (gNB) satisfies the prerequisite condition for enabling the two-step access. If the received signal strength measured by the terminal (UE) is greater than the first judgment threshold, it means that the terminal (UE) is closer to the network device (gNB), and the RTT is smaller, and a two-step access method may be adopted. Otherwise, adopting four-step access method. It should be noted that the first determination threshold in the embodiment of the present application is smaller than the first determination threshold in the prior art standard, so that the remote terminal can also access through the two-step random access method. The setting can be specifically set when the network equipment is deployed.

Step S103: and when the measured received signal strength exceeds a first judgment threshold, the terminal continuously sends the PRACH carrying the Preamble message to the network equipment according to the sequence, and transmits the PUSCH carrying the RRC message to the network equipment according to the first resource allocation information and the second resource allocation information.

In the embodiment of the application, when the measured received signal strength exceeds the first judgment threshold, a two-step access method is adopted. Namely, the terminal (UE) sends the PRACH carrying the Preamble message and the PUSCH carrying the RRC information to the network equipment (gNB) at one time by sending the MSGA according to the sequence.

Specifically, a terminal (UE) first waits for an RACH scheduling period according to random access resource information configured by the system, selects a Preamble, and sends a PRACH carrying the Preamble message to a network device (gNB). And, the PUSCH carrying the RRC information is transmitted directly according to the resource allocation mode indicated by the network equipment (gNB) without waiting for the network equipment (gNB) to respond to the random access request.

Step S104: and the network equipment receives and decodes the Preamble message, obtains the Preamble index and the time delay estimation value between the terminal and the network equipment, and determines time delay compensation according to the time delay estimation value between the terminal and the network equipment.

In the embodiment of the present application, the network device (gNB) receives and processes Preamble of the MSGA in the RO, and solves Preamble Index (Preamble Index) and a Time Advance (TA), which is an estimated value of time delay between the terminal (UE) and the network device (gNB). And determining the compensation time delay of PUSCH receiving of the MSGA according to the TA of the detection result.

Specifically, referring to the prior art standard, the Preamble is composed of a Cyclic Prefix (CP) and a Preamble sequence (sequence). The Preamble supports 4 long sequence preambles with the length of 839 and 9 short sequence preambles with the length of 139, the Preamble-rootsequence index indicates the length of the Preamble sequence and the index number of the root sequence of the Preamble sequence, and the terminal (UE) calculates cyclic shift according to high-level parameters to obtain 64 Preamble sequences in total and randomly selects one sequence from the 64 Preamble sequences to transmit. In the contention based random access procedure, a Preamble Index (Preamble Index) is randomly selected by the terminal. According to the preamble index, the network device (gNB) can establish a correspondence between the terminal (UE) and its configured corresponding communication resource.

The Timing Advance (TA) is used for uplink transmission of the terminal (UE), and means that a system frame for transmitting uplink data by the terminal (UE) is advanced by a certain time compared with a corresponding downlink frame, and the specific Advance is calculated by the network device (gNB) according to a random access Preamble sent by the terminal (UE), and then notified to the terminal (UE) by a Timing Advance Command (TAC). Because the distances between different terminals (UE) and the network device (gNB) are different, the time for receiving downlink data by different terminals (UE) is also different, and thus uplink information sent by different terminals (UE) can reach the network device (gNB) at different times to cause interference, so the network device (gNB) expects that the time for signals from different terminals (UE) in the same subframe to reach the network device (gNB) is basically aligned, and the network device (gNB) can correctly receive uplink data sent by the terminals (UE) as long as the signals fall within the CP range, thereby timing advance is required. The network equipment (gNB) estimates the timing advance of the terminal (UE) through the Preamble sent by the terminal (UE), the advance of the terminal (UE) in different distances is different, and then the TAC is notified to the terminal (UE), so that all uplink and downlink system frames are aligned in terms of the network equipment (gNB). For the specific method of TA calculation, reference may be made to the prior art specification, which is not described herein.

It is particularly noted that, in the embodiment of the present application, since the two-step access method is adopted, the terminal (UE) transmits a message carrying the RRC to the network device (gNB) through the PUSCH when the timing advance sent by the network device (gNB) has not been received. Therefore, the corresponding compensation delay needs to be determined according to the estimated value (TA) of the delay between the terminal (UE) and the network equipment (gNB).

Specifically, referring to fig. 6, the network device (gNB) receives the uplink signal of the terminal (UE) after the TA compensation delay, and may add an independent processing procedure to each of the plurality of compensation delays. In the next step, the compensation time delay is used for calibrating time domain signal reception, ensuring normal reception and processing of the signal.

Step S105: and the network equipment receives a time domain signal containing the PUSCH according to the time delay compensation calibration, decodes the load and processes the borne RRC message.

Specifically, referring to fig. 7, the network device (gNB) performs delay selection on the uplink time domain received signal of the time slot in which the PO is located according to the compensation delay. After the received time domain signal is calibrated by compensating the time delay, subsequent conventional processing (including removing CP, time-frequency transformation and the like) is carried out, so that the time domain signal is converted into a frequency domain signal, and then decoding processing is carried out.

Specifically, in the terminal two-step random access method in the remote scenario in the embodiment of the present application, a network device (gNB) receives a PRACH in an MSGA sent by a terminal (UE) and converts the PRACH into a frequency domain signal, and an access result is obtained according to PRACH frequency domain signal detection. If the preamble signal is successfully solved, determining the compensation time delay according to the TA, associating the compensation time delay with the PO to be received, receiving a corresponding PUSCH signal according to the compensation time delay value, converting the PUSCH signal into a frequency domain signal, and decoding the PUSCH, so that the terminal in a far-end scene can also smoothly pass through the two-step random access method network.

Step S106: and the network equipment returns an access response to the terminal according to the processing result.

And the network equipment (gNB) receives all the contents of the MSGA according to the processing result, and returns an access response to the terminal (UE) according to the processing result and the subsequent processing specification of the two-step random access flow.

Further, in a preferred embodiment provided by the present application, in step S101, the first resource allocation information includes a first PUSCH time domain resource allocation index, where the first PUSCH time domain resource allocation index is used to determine an OFDM symbol resource used by a PUSCH in a configured first PUSCH time domain resource allocation list, so that a tail symbol of the OFDM symbol resource is reserved, and a symbol set time length of the tail reserved is at least equal to a CP length of a PRACH preamble.

In the embodiment of the present application, when a terminal (UE) is far away from a network device (gNB), an uplink signal is not subjected to TA calibration and has a large delay, because RTT exceeds a guard length of a cyclic prefix of an OFDM signal, the signal cannot be successfully decoded, and a delayed PUSCH signal may also generate overlapping interference with other subsequent signals. Therefore, on the basis of considering the time delay factor, the PUSCH time domain resource allocation parameter of the MSGA needs to be set reasonably, so as to avoid overlapping interference between the delayed PUSCH signal and other subsequent signals. Through time domain resource allocation parameters, the PUSCH utilizes symbols with the serial numbers at the front in the time slot as much as possible, and a plurality of symbols at the tail part are reserved, so that the PUSCH with larger time delay can be prevented from generating overlapping interference with other signals. The length of time of the tail reserved symbol set is at least equal to the CP length of the PRACH preamble.

Specifically, referring to fig. 8, the PUSCH uses a slot as a time domain unit for transmitting signals, wherein 1 slot includes 14 OFDM symbols, and which OFDM symbols can be utilized to carry effective signals are determined by time domain resource allocation parameters. Typically, 14 OFDM symbols may be fully utilized. However, the terminal (UE) at the far end may cause a large propagation distance, and the MSGA in the two-step random access has not completed uplink synchronization to compensate for the delay, which may cause the PUSCH in the MSGA to have a large delay. In this case, the tail symbol of the PUSCH overlaps with the signal of the next slot to cause interference. By adjusting the time domain resource allocation, a small part of the symbols at the tail part are reserved and are not used, and the interference caused by uncompensation of time delay can be avoided.

And the PUSCH of the MSGA carries out time domain resource allocation through an RRC parameter 'msgA-PUSCH-TimeDomainAllocation'. The terminal (UE) uses the parameter as an index to obtain the information combination of the initial symbol number and the continuation symbol number through a public configuration table or a resource default configuration table. Taking the default Table as an example (refer to Table 6.1.2.1.1-2 of TS 38.214), when the index is 2, the starting symbol S is 0, and the number of continuation symbols L is 12, then in a slot containing 14 OFDM symbols, the PUSCH transmission uses the first 12 OFDM symbol resources, and the last 2 OFDM symbols are reserved for non-use. When the index is 3, the corresponding time domain resources occupy the first 10 of the 14 OFDM symbols in the same manner.

table-MSGA-PUSCH-TimeDomainAllocation Default configuration Table

Further, in a preferred embodiment provided by the present application, in step S101, the second resource allocation information includes a second PUSCH resource multiplexing indication factor, where the second PUSCH resource multiplexing indication factor is used to select an adopted resource multiplexing mode under the condition that the total number of POs is constant, so as to maximize the number of POs adopting frequency division multiplexing.

In the embodiment of the present application, the transmission timing PO of the PUSCH should preferentially adopt the resource configuration of frequency division multiplexing FDM, that is, PUSCH resources including multiple MSGAs in one time unit are multiplexed by different frequency resources.

Specifically, referring to fig. 9, the network device (gNB) may indicate the resource multiplexing mode of the PO through configuration of different multiplexing indication factors. Under the condition of a certain total PO number, the FDM multiplexing mode is preferentially adopted, and the TDM multiplexing mode is not used or is reduced as much as possible. If a time slot contains PUSCH resources of multiple MSGAs, even if protection symbols between POs can be configured, too compact allocation in the time domain is not beneficial to signals with large delay tolerance, so multi-PO configuration should be achieved through FDM multiplexing as much as possible. The multiplexing indicator should be configured to maximize the number of POs using frequency division multiplexing.

Specifically, the network equipment (gNB) indicates the multiplexing factor by the following RRC parameters, for example:

nrofMsgA-PO-FDM, which represents the PO number of frequency division multiplexing and takes values of 1, 2, 4 and 8;

the nrofSlotsMsgA-PUSCH represents the number of time slots occupied by the time division multiplexing PO, and takes values of 1, 2, 3 and 4;

and nroflsgA-PO-PerSlot, which represents the number of the time division multiplexing POs in a time slot unit, and takes values of 1, 2, 3 and 6.

Considering that the remote access needs to reserve part of symbols in a symbol set to avoid interference caused by time delay, the number of available symbols is limited, and a configuration of PO including a plurality of TDM in one time slot is not suggested, so that nroflsga-PO-PerSlot is set to 1.

In general, a larger value should be set for nroflsgA-PO-FDM as much as possible, and the minimum nroflslotsmsggA-PUSCH is ensured.

Further, in a preferred embodiment provided by the present application, in step S104, the network device receives and decodes the Preamble message, obtains a Preamble index and a delay estimation value between the terminal and the network device, and determines the delay compensation according to the delay estimation value between the terminal and the network device, which specifically includes:

Specifically, the second determination threshold is set to T _{TA_THR} ＝α·T _cp，min Wherein, T _cp，min Is the minimum CP length in the symbol set of the PUSCH, and alpha is less than or equal to 1 as a control coefficient. In general, α may be 1, or may be other values smaller than 1 according to actual deployment requirements in combination with the network situation. The related principle is described here by taking α ═ 1 as an example.

It is understood that the estimated value of the time delay between the terminal (UE) and the network equipment (gNB) is less than or equal to T _{TA_THR} By time, it is meant that the estimate of the time delay between the terminal (UE) and the network equipment (gNB) is less than or equal to the minimum CP length in the symbol set of the PUSCH. In this case, the reception and processing of the signal can be realized by a conventional process without performing the delay compensation, and thus the delay compensation is determined to be 0.

When the estimated time delay value between the terminal (UE) and the network equipment (gNB) is larger than T _{TA_THR} Time delay estimation value between a terminal (UE) and a network device (gNB) is larger than the minimum CP length in the symbol set of the PUSCH. In this case, the uplink signal of the terminal (UE) must be calibrated by delay compensation to successfully receive and process the signal.

It can be understood that, when there is a need for random access in all terminals (UEs) in a plurality of remote scenarios, all the terminals (UEs) need to send a PRACH carrying a Preamble message to a network device, and transmit a PUSCH carrying RRC information to a network device (gNB) according to the first resource allocation information and the second resource allocation information. For a terminal in which the estimated value of the time delay with the network device (gNB) is less than or equal to the second decision threshold, it suffices to determine the time delay compensation to be 0 according to the aforementioned method.

However, for a terminal in which the delay estimate with the network device (gNB) is greater than the second decision threshold, it does not have to be mapped one-to-one to compensate the delay, but can be combined into fewer delay terms. Referring to fig. 10, the merging principle is that each TA is grouped, the difference between each TA in the grouped items is smaller than the second determination threshold, and the compensation delay takes the minimum value in the group.

The specific grouping process is as follows:

1.2 sets were set up: the method comprises a detection time delay set and a compensation time delay set, wherein the detection time delay set corresponds to a result (RO, a leading index and a detection time delay TA) obtained by PRACH detection, and the compensation time delay set corresponds to the compensation time delay selected by a subsequent adjusting signal. For all PRACH detection results, firstly according to T _TA，detect ＞T _{TA_THR} Conditional screening of (1), T _TA，detect Is the value of the detection delay. And screening the rest items, sequencing the rest items from small to large according to TA, and inserting the rest items into the detection time delay set one by one. The compensation delay set is initialized to be an empty set, and then the compensation delay set is inserted according to the detection delay TA of the first item of the detection delay set. The significance of the screening process is that: the smaller delay is processed by the normal process without being incorporated into the special process of compensating for the delay (i.e., the compensation described above)Case of 0 time delay).

2. Defining an index i of a detection delay set, wherein an initial value is 0, and the index i points to a first item of the set; and defining a compensation time delay set index j, wherein an initial value of 0 points to the first item of the set.

3. i is i +1, and whether the difference value of the detection time delay TA of the referenced item of the current detection time delay set and the compensation time delay referenced by j is less than T or not is judged _{TA_THR} . If yes, repeating the step, otherwise, carrying out the step 4.

4. And inserting the detection delay TA of the ith item of the current detection delay set into the compensation delay set, wherein j is j +1, and returning to the step 3.

The steps are circularly processed until all the detection delay sets are judged, and a compensation delay set is generated. The compensation time delay set is based on the original detection time delay set, and the close detection time delays TA are converged and combined, so that the working overhead of time adjustment compensation in the next signal processing is reduced as much as possible on the premise of ensuring that the PUSCH of each UE can be reasonably subjected to time delay compensation processing.

Referring to fig. 11, the present application further discloses a method for terminal access in a remote scenario, which is deployed at a network device side, and specifically includes:

step S201: a wireless module of the network equipment sends broadcast information to the terminal, wherein the broadcast information comprises a first judgment threshold value, first resource allocation information used for indicating a terminal PUSCH time domain resource allocation mode and second resource allocation information used for indicating a terminal PUSCH resource multiplexing mode.

In the embodiment of the application, a network device (gNB) sends broadcast information including a first judgment threshold, first resource allocation information for indicating a terminal (UE) PUSCH time domain resource allocation mode and second resource allocation information for indicating a terminal (UE) PUSCH resource multiplexing mode to a terminal (UE) in a cell through a wireless module. Indicating a mode (two steps or four steps) adopted by a terminal (UE) to access through a first judgment threshold; and indicating the terminal (UE) by the first resource allocation information in which way to configure the PUSCH time domain resource, and indicating the terminal (UE) by the second resource allocation information in which way to configure the PUSCH resource multiplexing way. The broadcast information can be sent based on the related communication protocol and data message format in the prior art, by defining the related RRC system parameters, or by a custom protocol and message format.

Step S202: the wireless module of the network device receives:

and the terminal continuously sends the PRACH carrying the Preamble message to the network equipment according to the sequence, and transmits the PUSCH carrying the RRC message to the network equipment (gNB) according to the first resource allocation information and the second resource allocation information.

Specifically, the terminal (UE) first waits for an RACH scheduling period according to random access resource information configured by the system, selects a Preamble, and sends a PRACH carrying the Preamble message to the network device (gNB). And, the PUSCH carrying the RRC message is transmitted directly according to the resource allocation mode indicated by the network equipment (gNB) without waiting for the network equipment (gNB) to respond to the random access request.

And the network equipment (gNB) receives the PRACH carrying the Preamble and the PUSCH carrying the RRC message sent by the terminal (UE).

Step S203: the wireless module of the network device converts the received Preamble into a frequency domain signal.

After receiving the preamble signal sent by the terminal (UE), the radio module of the network device (gNB) first converts the MSGA preamble signal into a frequency domain signal. The method for converting the preamble signal into the frequency domain signal can be realized based on the prior art specification, and the method does not have special requirements.

Step S204: and the wireless module of the network equipment sends the frequency domain signal of the Preamble to the data module of the network equipment.

And the wireless module of the network equipment (gNB) converts the preamble signal into a frequency domain signal, and then sends the frequency domain signal to the data module of the network equipment (gNB), and the data module performs subsequent processing.

Step S205: and a data module of the network equipment decodes the Preamble to obtain a time delay estimation value between the terminal and the network equipment, and determines time delay compensation according to the time delay estimation value between the terminal and the network equipment.

In the embodiment of the present application, a data module of a network device (gNB) decodes a Preamble, and solves a Preamble Index (Preamble Index) and a Time Advance (TA), which is an estimated value of a time delay between a terminal (UE) and the network device (gNB). And determining the compensation time delay of PUSCH receiving of the MSGA according to the TA of the detection result.

Regarding the format and selection mechanism of Preamble, and the specific method and principle of Timing Advance (TA) calculation, etc., reference may be made to the prior art standard, and the foregoing has been mentioned, and no further description is given here.

Step S206: a data module of the network device sends the delay compensation and the PUSCH identification associated with the delay compensation to a radio module of the base station.

Specifically, the data module of the network device (gNB) sends the delay compensation and the PUSCH identifier associated therewith to the radio module of the network device (gNB), so that the radio module of the network device (gNB) can calibrate the received signal according to the delay compensation.

Step S207: and the wireless module of the network equipment calibrates and receives the time domain signal which is associated with the time delay compensation and contains the PUSCH according to the time delay compensation, converts the time domain signal into a frequency domain signal and sends the frequency domain signal to the data module of the network equipment.

Specifically, referring to fig. 7, a radio module of a network device (gNB) performs delay selection on an uplink time domain received signal of a time slot in which a PO is located according to the compensation delay. After time delay compensation is carried out, the PUSCH-containing time domain signal associated with the time delay compensation is calibrated and received, subsequent conventional processing (including CP removal, time-frequency transformation and the like) is carried out, the time domain signal is converted into a frequency domain signal, and the frequency domain signal is sent to a data module of the network equipment (gNB), so that the data module of the network equipment (gNB) can decode the signal.

Step S208: and the data module of the network equipment decodes the PUSCH according to the frequency domain signal and processes the RRC message carried by the PUSCH.

Specifically, the data module of the network device (gNB) decodes the payload and processes the RRC message carried in accordance with the PUSCH signal converted into the frequency domain signal reported by the radio module of the network device (gNB).

In the terminal two-step random access method in the remote scene in the embodiment of the application, a wireless module of a network device (gNB) receives a PRACH in an MSGA sent by a terminal (UE) and converts the PRACH into a frequency domain signal, and a data module of the network device (gNB) detects the PRACH frequency domain signal to obtain an access result. If the preamble signal is successfully solved, determining the compensation time delay according to the TA, associating the compensation time delay with the PO to be received, receiving the corresponding PUSCH signal according to the compensation time delay value by the wireless module of the network equipment (gNB), converting the PUSCH signal into a frequency domain signal, and decoding the PUSCH by the data module of the network equipment (gNB), so that the terminal in a far-end scene can smoothly pass through the two-step random access method network.

Step S209: and the network equipment returns an access response to the terminal according to the processing result.

Further, in a preferred embodiment provided by the present application, in step S201, the first resource allocation information includes a first PUSCH time domain resource allocation index, where the first PUSCH time domain resource allocation index is used to determine an OFDM symbol resource used by a PUSCH in a configured first PUSCH time domain resource allocation list, so that a tail symbol of the OFDM symbol resource is reserved, and a symbol set time length of the tail reserved is at least equal to a CP length of a PRACH preamble.

In the embodiment of the present application, when a terminal (UE) is far away from a network device (gNB), an uplink signal is not subjected to TA calibration and has a large delay, because RTT exceeds a guard length of a cyclic prefix of an OFDM signal, the signal cannot be successfully decoded, and a delayed PUSCH signal may also generate overlapping interference with other subsequent signals. Therefore, on the basis of considering the time delay factor, the PUSCH time domain resource allocation parameter of the MSGA needs to be set reasonably, so as to avoid overlapping interference between the delayed PUSCH signal and other subsequent signals. Through time domain resource allocation parameters, the PUSCH utilizes symbols with the front serial numbers in the time slot as much as possible, and a plurality of symbols at the tail part are reserved, so that the PUSCH with larger time delay and other signals can be prevented from generating overlapping interference. The length of time of the tail reserved symbol set is at least equal to the CP length of the PRACH preamble.

Specifically, referring to fig. 8, by adjusting the time domain resource allocation, specific principles, methods, parameter settings, etc. for reserving the tail small part of the symbols not to be used can be referred to the prior art standards, and the foregoing has been mentioned and will not be described herein again.

Further, in a preferred embodiment provided by the present application, in step S201, the second resource allocation information includes a second PUSCH resource multiplexing indication factor, where the second PUSCH resource multiplexing indication factor is used to select an adopted resource multiplexing mode under the condition that the total number of POs is constant, so as to maximize the number of POs adopting frequency division multiplexing.

Specifically, referring to fig. 9, the network device (gNB) may indicate the resource multiplexing mode of the PO through configuration of different multiplexing indication factors. Under the condition of a certain total PO number, the multiplexing mode of FDM is preferentially adopted, and the multiplexing mode of TDM is not used or is reduced as much as possible. If a time slot contains PUSCH resources of multiple MSGAs, even if protection symbols between POs can be configured, too compact allocation in the time domain is not beneficial to signals with large delay tolerance, so multi-PO configuration should be achieved through FDM multiplexing as much as possible. The multiplexing indicator should be configured to maximize the number of POs using frequency division multiplexing. The network device (gNB) indicates the multiplexing factor through the RRC parameter, and for the specific RRC parameter setting method, reference may be made to the prior art standard, which has been mentioned above, and details are not described here.

Further, in a preferred embodiment provided by the present application, in step S205, the data module of the network device decodes the Preamble, obtains a delay estimation value between the terminal and the network device, and determines the delay compensation according to the delay estimation value between the terminal and the network device, which specifically includes:

wherein the second judgment threshold does not exceed the duration occupied by the CP of one PUSCH at most.

Specifically, the second determination threshold is set to T _{TA_THR} ＝α·T _cp，min Wherein, T _cp，min Is the minimum CP length in the symbol set of the PUSCH, and alpha is less than or equal to 1 as a control coefficient. In general, α may be 1, or may be other values smaller than 1 according to actual deployment requirements in combination with the network situation. The related principle is described by taking α ═ 1 as an example.

It is understood that the estimated value of the time delay between the terminal (UE) and the network equipment (gNB) is less than or equal to T _{TA_THR} Time-delay between the terminal (UE) and the network equipment (gNB) is less than or equal to the minimum CP length in the symbol set of PUSCH. In this case, the reception and processing of the signal can be realized by a conventional process without performing the delay compensation, and thus the delay compensation is determined to be 0.

Further, in a preferred embodiment provided by the present application, in step S205, when there are multiple terminals sending PRACH carrying Preamble messages to the network device in the same transmission time of the PRACH, the data module of the network device decodes the Preamble to obtain a delay estimation value between the terminal and the network device, and determines the delay compensation according to the delay estimation value between the terminal and the network device, which specifically includes:

It can be understood that when terminals (UE) in a plurality of remote scenarios have a requirement for random access, the plurality of terminals (UE) all need to send PRACH carrying Preamble information to a network device, and transmit a PUSCH carrying RRC information to the network device (gNB) according to the first resource allocation information and the second resource allocation information. For a terminal in which the estimated value of the time delay with the network device (gNB) is less than or equal to the second decision threshold, it suffices to determine the time delay compensation to be 0 according to the aforementioned method.

However, for a terminal in which the delay estimate with the network device (gNB) is greater than the second decision threshold, it does not have to be mapped one-to-one to compensate the delay, but can be combined into fewer delay terms. Referring to fig. 10, the merging principle is that each TA is grouped, the difference between each TA in the grouped items is smaller than the second judgment threshold, and the compensation delay takes the minimum value in the group.

The specific grouping process is described above and will not be described herein.

Referring to fig. 12, the present application further discloses a network device deployment method, which is applicable to terminal access in a remote scenario and includes:

the time-frequency domain serial-parallel conversion function of the network equipment is deployed in a wireless module of the network equipment;

the network device processing function is deployed in a data module of the network device.

Specifically, in the present application, the network device (gNB) adopts the function division of the high and low physical layers, sinks the low physical layer function responsible for the time-frequency domain serial-parallel conversion to the radio module gNB _ RU, and deploys the baseband processing function to the data module gNB _ DU of the base station in the high layer. And the gNB _ RU receives the PRACH of the MSGA and converts the PRACH into a frequency domain signal to be transmitted to the gNB _ DU, and the gNB _ DU obtains an access result according to the detection of the PRACH frequency domain signal. If the preamble signal is successfully decoded, the TA are combined to generate a compensation time delay, and the compensation time delay is associated with the PO to be received and then sent to the gNB _ RU. And the gNB _ RU receives the PUSCH signal responded according to the compensation delay value and reports the frequency domain signal to the gNB _ DU. And the gNB _ DU carries out decoding processing of the PUSCH again.

Referring to fig. 13, a low physical layer process flow of a radio module gNB-RU incorporating time alignment is shown. The time calibration is a newly introduced module, and performs special processing on the uplink signal of the time slot where the PO is located according to the compensation time delay obtained by PRACH preamble receiving in the MSGA. And adjusting the time slot starting point according to the time delay, selecting a time domain signal, then executing the rest low physical layer operation (removing CP and time frequency transformation), and outputting a frequency domain signal.

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

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

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

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

While the preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all alterations and modifications as fall within the scope of the application.

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

Claims

1. A terminal access method in a far-end scene is characterized by comprising the following steps:

the network equipment receives and decodes the Preamble message, obtains a Preamble index and a time delay estimation value between the terminal and the network equipment, and determines time delay compensation according to the time delay estimation value between the terminal and the network equipment:

when the time delay estimated value between the terminal and the network equipment is larger than a second judgment threshold value, the time delay estimated value between the terminal and the network equipment is used as time delay compensation,

wherein the second judgment threshold does not exceed the time length occupied by the CP of one PUSCH at most; the network equipment receives a time domain signal containing a PUSCH according to the time delay compensation calibration, decodes the load and processes the borne RRC message;

2. The terminal access method in the remote scenario of claim 1, wherein the first resource allocation information includes a first PUSCH time domain resource allocation index, the first PUSCH time domain resource allocation index is used for determining the OFDM symbol resources used by PUSCH in the configured first PUSCH time domain resource allocation list, such that the OFDM symbol resources are tail symbol reserved, and the tail reserved symbol set time length is at least equal to the CP length of the PRACH preamble.

3. The terminal access method in the remote scenario according to claim 1, wherein the second resource allocation information includes a second PUSCH resource multiplexing indication factor, and the second PUSCH resource multiplexing indication factor is used for selecting an adopted resource multiplexing mode so as to maximize the number of POs using frequency division multiplexing when the total number of POs is fixed.

4. The terminal access method in the remote context of claim 1, wherein when there are multiple PRACH's in which the terminal sends Preamble messages to the network device in the same PRACH transmission opportunity, the network device receives and decodes the Preamble messages to obtain Preamble indexes and a delay estimation value between the terminal and the network device, and determines delay compensation according to the delay estimation value between the terminal and the network device, further comprising:

5. A terminal access method based on a far-end scene is characterized by comprising the following steps:

the wireless module of the network device receives:

the data module of the network equipment decodes the Preamble to obtain a time delay estimation value between the terminal and the network equipment, and determines time delay compensation according to the time delay estimation value between the terminal and the network equipment:

wherein the second judgment threshold does not exceed the time length occupied by the CP of one PUSCH at most;

6. The terminal access method in the remote scenario of claim 5, wherein the first resource allocation information includes a first PUSCH time domain resource allocation index, the first PUSCH time domain resource allocation index is used to determine the OFDM symbol resources used by PUSCH in the configured first PUSCH time domain resource allocation list, such that the OFDM symbol resources are tail symbol reserved, and the tail reserved symbol set time length is at least equal to the CP length of PRACH preamble.

7. The terminal access method in the remote scenario according to claim 5, wherein the second resource allocation information includes a second PUSCH resource multiplexing indicator factor, and the second PUSCH resource multiplexing indicator factor is used for selecting the resource multiplexing mode to be used so as to maximize the number of POs using frequency division multiplexing when the total number of POs is constant.

8. The terminal access method in the far-end scenario according to claim 5, wherein when there are multiple terminals sending PRACH carrying Preamble messages to the network device in the same PRACH transmission opportunity, the data module of the network device decodes the Preamble to obtain a delay estimation value between the terminal and the network device, and determines the delay compensation according to the delay estimation value between the terminal and the network device, which specifically includes: