A method for allocating random access resources based on a multi-antenna base station

Abstract

This invention discloses a method for allocating random access resources based on a multi-antenna base station, comprising the following steps: establishing a random access relationship between the base station and users; initializing available random access resources based on the number of users and the number of antennas; calculating the expected success rate of the number of random access users under the multi-antenna scenario, and obtaining the optimal number of random access resources by maximizing the expected success rate; and allocating random access resources based on the optimal number of random access resources. This invention can maximize system resource efficiency through the rational allocation of random access resources.

Description

Technical Field

[0001] This invention relates to the field of mobile communication technology, and in particular to a method for random access resource allocation based on a multi-antenna base station. Background Technology

[0002] Cellular networks are a wireless communication technology that increases network coverage and capacity by dividing the communication area into many smaller areas. Random access technology in cellular networks refers to the process by which a mobile device randomly selects an idle channel to communicate when establishing a connection with the network. Random access technology in cellular networks is widely used, especially in 4G and 5G mobile communication technologies. Random access technology makes communication more efficient and stable for mobile devices, while also reducing communication latency and packet loss rates, thus improving communication quality and reliability.

[0003] The implementation of random access technology mainly involves two aspects: channel allocation and access control. Channel allocation refers to assigning available channels to mobile devices to avoid communication interference caused by multiple devices using the same channel simultaneously. Access control refers to controlling access requests to prevent network congestion and quality degradation caused by too many devices.

[0004] The random access process primarily relies on a preamble sequence in the base station, which helps the base station allocate random access channels and confirm the access request of mobile devices. During random access, the mobile device first sends a signal containing the random access preamble sequence to identify its starting position. The base station, by recognizing the preamble sequence, allocates a random access channel to the mobile device and confirms its access request through this channel. While multi-antenna systems are widely used for multi-user random access, much current research considers the single-antenna scenario, where the preamble collision threshold is 1. This is not applicable to multi-antenna systems, and multi-antenna systems can lead to unreasonable allocation of random access resources for multiple users. Summary of the Invention

[0005] The purpose of this invention is to provide a method for random access resource allocation based on multi-antenna base stations. This invention can maximize system resource efficiency through the rational allocation of random access resources.

[0006] The technical solution of this invention: A method for random access resource allocation based on a multi-antenna base station, comprising the following steps:

[0007] Step 1: Establish a random access relationship between the base station and the user;

[0008] Step 2: The base station initializes the available random access resources based on the number of users and the number of antennas;

[0009] Step 3: Calculate the expected success of the number of random access users under the multi-antenna scenario, and obtain the optimal number of random access resources by maximizing the expected success.

[0010] Step 4: The base station allocates random access resources based on the optimal number of random access resources.

[0011] The above-described random access resource allocation method based on multi-antenna base stations includes the following steps in the user's random access process:

[0012] Step 1.1: The user initiates a random access request and sends the random access preamble sequence Msg1 to the base station;

[0013] Step 1.2: After receiving the preamble sequence Msg1 sent by the user, the base station sends the random access preamble response Msg2 to the user.

[0014] Step 1.3: The user obtains the uplink resources allocated by the base station based on Msg2, and sends PRC connection request information Msg3 on the allocated uplink resources. Msg3 contains the contention resolution ID.

[0015] Step 1.4: The base station returns a PRC connection establishment success message Msg4 to the user. Msg4 contains the contention resolution ID.

[0016] Step 5: The user determines whether the received contention resolution ID and the sent contention resolution ID are the same. If they are the same, the contention is considered resolved and random access is successful. If they are different, the contention fails and the user returns to step 1.1 to re-initiate the random access request.

[0017] In the aforementioned random access resource allocation method based on multi-antenna base stations, in step 1.2, after the base station receives the user's preamble sequence Msg1, it first determines the user's access resource status. The user is defined as idle (I) when no preamble sequence has been sent on the random access resource; as conflict (C) when a preamble sequence selection conflict occurs; and as successful selection (S) when no conflict occurs. This is represented as follows:

[0018]

[0019] In the formula: n is the number of users simultaneously sending the preamble sequence at the current time, and K is the number of base station antennas.

[0020] In the aforementioned random access resource allocation method based on multi-antenna base stations, step 3, the formula for calculating the expected success rate is as follows:

[0021]

[0022] Where M is the number of users randomly accessing the base station, N is the number of allocated random access resources, K is the number of base station antennas, and C is the combination formula.

[0023] In the aforementioned random access resource allocation method based on multi-antenna base stations, step 3, maximizing the expected success rate, is expressed by the formula:

[0024]

[0025]

[0026] Then, using a brute-force search algorithm, the optimal number N of random access resources is calculated based on a fixed number of antennas and users. * .

[0027] Compared with existing technologies, this invention proposes a multi-antenna random access resource allocation scheme. Through multi-antenna technology, multiple user equipments can transmit preamble sequences in parallel without conflict. The base station of this invention initializes available random access resources based on the number of users and antennas; then, it calculates the expected success rate of random access users under multi-antenna conditions. By maximizing the expected success rate, the optimal number of random access resources is obtained. Finally, the base station allocates random access resources based on the optimal number of random access resources. Therefore, this invention can maximize system resource efficiency through the rational allocation of random access resources. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the random access resource update process of the present invention;

[0029] Figure 2 This is a schematic diagram of the random access process of the present invention;

[0030] Figure 3 This is a schematic diagram of the random access process on the user side of the present invention;

[0031] Figure 4 This is a schematic diagram of the random access process on the base station side of the present invention. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0033] Example: A method for random access resource allocation based on multi-antenna base stations, such as... Figure 1 As shown, it includes the following steps:

[0034] Step 1: Establish a random access relationship between the base station and the user; such as Figure 2 As shown, the random access process for users includes the following steps:

[0035] Step 1.1: The user initiates a random access request, sending a random access preamble sequence Msg1 to the base station. Specifically, the user terminal obtains the random access-related configuration message from the information broadcast by the base station, then randomly selects a preamble sequence from the preamble sequence set, and sends Msg1 to the base station on the Physical Random Access Channel (PRACH) indicated by the base station. The base station detects and decodes Msg1 in the subframe configured with PRACH resources to obtain the preamble sequence code indicating that the terminal is ready to prepare a data frame.

[0036] Step 1.2: After receiving the preamble sequence Msg1 sent by the user, the base station sends the random access preamble response Msg2 to the user. Specifically, after receiving the preamble sequence sent by the terminal, the base station sends a random access response and completes the uplink synchronization of the terminal based on the time of receiving the preamble sequence. The user listens to the Physical Downlink Control Channel (PDCCH) within the Random Access Response (RAR) window to obtain the downlink control message indicating the position of Msg2 on the Physical Downlink Shared Channel (PDSCH), and receives and decodes Msg2 on the corresponding PDSCH position. During this process, after receiving the user's preamble sequence Msg1, the base station determines the user's access resource status. Idle access is defined as I when the user has not sent a preamble sequence on the random access resource; conflict occurs when selecting the preamble sequence, defined as C; and successful selection is defined as S when no conflict occurs, as shown below:

[0037]

[0038] In the formula: n is the number of users simultaneously sending the preamble sequence at the current time, and K is the number of base station antennas.

[0039] Step 1.3: The user obtains the uplink resources allocated by the base station based on Msg2. The user sends a PRC connection request message Msg3 on the allocated uplink resources. Msg3 contains the contention resolution ID. Specifically, the user obtains the uplink scheduling authorization and user identification code based on Msg2, and transmits Msg3 carrying the user identification code (i.e., the contention resolution ID) on the uplink shared channel (UL-SCH) allocated to it. The base station listens on this uplink channel in order to carry out subsequent data transmission.

[0040] Step 1.4: The base station returns a PRC connection establishment success message Msg4 to the user. Msg4 contains the second contention resolution ID.

[0041] Step 5: The user determines whether the received contention resolution ID and the sent contention resolution ID are the same. If they are the same, the contention is considered resolved and random access is successful. If they are different, the contention fails and the user returns to step 1.1 to re-initiate the random access request.

[0042] Figure 3 This indicates the random access process on the user side. Figure 4 This describes the random access procedure on the base station side.

[0043] Step 2: The base station initializes the available random access resources based on the number of users and the number of antennas. This step involves the base station updating the number of random access resources after determining whether a user's random access is successful, so as to maximize the utilization of the base station's random access resources in the future.

[0044] Step 3: Calculate the expected success rate of random access users in the multi-antenna scenario, and obtain the optimal number of random access resources by maximizing the expected success rate. In this step, if the number of antennas is K, the collision capacity is equal to the number of antennas K of the base station. Assume that users can transmit preamble sequences in parallel in the multi-antenna scenario, and consider whether the preamble sequence is utilized by users.

[0045] Based on the recursive operation of formula (2), the expected success rate of the number of random access users in the case of multiple antennas can be obtained as formula (3):

[0046]

[0047]

[0048] Where M is the number of users randomly accessing the base station, N is the number of allocated random access resources, K is the number of base station antennas, and C is the combination formula.

[0049] Step 4: The base station allocates random access resources based on the optimal number of random access resources. In this step, the objective of optimizing the resource allocation problem is to maximize the expected success rate of the number of random access users. Therefore, the mathematical problem is modeled as follows:

[0050]

[0051] Using a brute-force search algorithm (brute-force search is a very general problem-solving technique that involves systematically enumerating all possible candidate solutions and checking whether each candidate solution matches the problem description; it is a conventional technique and will not be described in detail in this embodiment), the optimal number N of random access resources can be obtained based on a fixed number of antennas and users.* This yields the expected number of randomly accessed users who will successfully connect. Furthermore, based on the dynamic changes in the number of users, the most suitable number of random access resources can be determined in real time.

[0052] In summary, this invention proposes a multi-antenna random access resource allocation scheme. Through multi-antenna technology, multiple user equipments can transmit preamble sequences in parallel without collisions. This invention enables the rational allocation of random access resources, maximizing system resource efficiency.

Claims

1. A method for random access resource allocation based on a multi-antenna base station, characterized in that: Includes the following steps: Step 1: Establish a random access relationship between the base station and the user; Step 2: The base station initializes the available random access resources based on the number of users and the number of antennas; Step 3: Calculate the expected success of the number of random access users under the multi-antenna scenario, and obtain the optimal number of random access resources by maximizing the expected success. Step 4: The base station allocates random access resources based on the optimal number of random access resources; In step 3, the formula for calculating the expected success is as follows: in, The number of users randomly accessed by the base station. The number of random access resources allocated. The number of base station antennas. The formula for combinations; In step 3, maximizing the expected success is expressed by the formula: ； Then, using a brute-force search algorithm, the optimal number of random access resources is calculated based on a fixed number of antennas and users. .

2. The random access resource allocation method based on a multi-antenna base station according to claim 1, characterized in that: The random access process for users includes the following steps: Step 1.1: The user initiates a random access request and sends the random access preamble sequence Msg1 to the base station; Step 1.2: After receiving the preamble sequence Msg1 sent by the user, the base station sends the random access preamble response Msg2 to the user. Step 1.3: The user obtains the uplink resources allocated by the base station based on Msg2, and sends RRC connection request information Msg3 on the allocated uplink resources. Msg3 contains the contention resolution ID. Step 1.4: The base station returns an RRC connection establishment success message Msg4 to the user. Msg4 contains the contention resolution ID. Step 1.5: The user determines whether the received contention resolution ID and the sent contention resolution ID are the same. If they are the same, the contention is considered resolved and random access is successful. If they are different, the contention fails and the user returns to step 1.1 to re-initiate the random access request.

3. The random access resource allocation method based on a multi-antenna base station according to claim 2, characterized in that: In step 1.2, after the base station receives the user's preamble sequence Msg1, it first determines the user's access resource status. The user is defined as having no preamble sequence sent on the random access resource. A conflict is defined as a conflict that occurs when the selection of the leader sequence is conflicted. A successful selection is defined as the selection of a leader sequence without conflict. , represents the following: ； In the formula: This represents the number of users simultaneously sending the preamble sequence at the current time. This refers to the number of base station antennas.

Images