CN107689929B - Scheduling method for evolution towards 5G low delay - Google Patents

Abstract

The present invention provides a scheduling method for 5G low-latency evolution. Scheduling users, inserting emergency service users and retransmission service users into the pre-scheduled user queue; multiplexing group packets of sending users and sending them to the baseband; returning the failed retransmission users/new data unsuccessfully to the user queue, and the urgent service has not been sent back to the queue. Users who successfully send will generate a preemption queue return. The scheduling method proposed in this application can process retransmission and new transmission services in parallel, greatly reducing the processing time of the MAC layer, enabling the system to smoothly evolve towards low latency, and better meeting the low latency requirements of 5G in the future.

Description

A Scheduling Method for Evolution to 5G Low Latency

technical field

The present invention relates to the field of communication technologies, and more particularly, to a scheduling method for 5G low-latency evolution.

Background technique

The 3rd Generation Partnership Project Long Term Evolution LTE system and its enhanced LTE-advanced can work based on two systems, one is the frequency division duplex system, the downlink transmission and the uplink transmission are carried in the paired spectrum, and the two frequency division duplex , to avoid mutual frequency band interference; the other is the time division duplex system, the downlink transmission and the uplink transmission are carried on the same frequency point, and the downlink transmission and the uplink transmission are time division duplex on the same frequency to avoid mutual time slot interference.

With the enrichment of service types, there are some services that are sensitive to delay, which are called low-latency services, and the end-to-end delay is required to reach the millisecond level. In the existing LTE system, after the current subframe is scheduled, the round-trip delay is at least 8 milliseconds. If the data needs to be retransmitted, it needs to wait for 8 milliseconds, and the waiting time is relatively long.

In the current wireless communication system, PDCP data needs to go through the protocol layers below the PDCP layer, that is, the MAC layer and the RLC layer, and then be sent to the physical layer, and then sent out through the physical layer. In sequence, a data header of a corresponding protocol layer is established for the data layer by layer, and the established data header and the data are bound and stored in the service cache of each protocol layer.

In addition, the main scheduling process of the MAC layer is serial. The underlying data is received first, and according to the underlying feedback result (ACK or NACK) during scheduling, the retransmission users whose feedback is NACK is preferentially processed, and then the users who have new data to be sent are processed. . That is, it is necessary to receive the feedback result of the baseband to start processing the MAC layer of the corresponding subframe, and the retransmission data and the new transmission data are transmitted independently. This serial processing method limits the processing time of the MAC layer, making the system to low time A bottleneck occurs when the evolution is delayed.

SUMMARY OF THE INVENTION

The present invention provides a scheduling method for 5G low-latency evolution that overcomes the above problems or at least partially solves the above problems.

According to an aspect of the present invention, a scheduling method for evolution to 5G low-latency is provided, including:

Step 1, receiving newly transmitted data in the current subframe and generating a pre-scheduled user queue, synchronously receiving retransmission service and/or emergency service data;

Step 2, adjusting the pre-scheduling users in the scheduling queue, and inserting emergency service users and retransmission service users into the pre-scheduling user queue;

Step 3, sending user multiplexing group packets to baseband processing according to the agreed number of users;

Step 4: Return to the queue of users who fail to retransmit/retransmit new data successfully, and return to a preemption queue for users whose emergency services are not successfully sent.

Wherein, the step 2 further includes:

Based on the queue length and the number of users required by the baseband, emergency service users and retransmission service users replace users in the pre-scheduled queue corresponding to newly transmitted data.

Wherein, the step 4 further includes:

Return the queue of users who fail to retransmit/successfully send new data to the pre-scheduling module for rearranging; users who fail to send urgent services will generate a preemption queue, and continue to go through the preemption process in the next real-time processing subframe to send first.

Wherein, step 4 further comprises:

The baseband correctly receives the multiplexed packet data and matches the information stored in the Hp process, demultiplexes the data, and sends it to the upper layer; or

The baseband does not correctly receive the multiplexed packet data or does not match the information stored in the Hp process, determine that the number of transmissions does not reach the maximum number of transmissions configured for the user, generate a retransmission queue, and initiate retransmission processing; or

The excess number of users is returned to the respective queues by the MAC itself.

Wherein, step 2 further includes:

Step 21, receiving the pre-scheduling queue result of the corresponding subframe;

Step 22, it is determined that the retransmission queue or the preemption queue is not empty, or that there is a sudden emergency service;

Step 23, the retransmission is added to the retransmission failure user queue, the emergency service is sent first, and the emergency service that is not successfully sent is put into the preempting user queue.

Wherein, step 22 further comprises:

If there is a user to be transmitted with the same id in the current subframe pre-scheduling queue, replace the user and write the original pre-sent user into the new data unsent queue;

If there is no user to be transmitted with the same id in the pre-scheduling queue of the current subframe, determine that there are idle resources and the number of users in the pre-scheduling queue does not exceed the maximum number of users supported by the TTI, allocate resources for the user, and add the user to the sending queue.

Wherein, step 22 further comprises:

If there is a retransmission user queue, and there are users with the same id to be transmitted in the current subframe pre-scheduling queue, the retransmission users will be put into the sending queue, and the pending users in the original pre-scheduling queue will be put into the new data unsent queue. retransmit user;

If there is an uplink preempting user queue, and there are users with the same id to be transmitted in the pre-scheduling queue of the current subframe, the pre-empting users will be placed in the sending queue, and the users to be transmitted in the original pre-scheduling queue will be placed in the new data unsent queue. , but the priority is lower than the retransmission user;

If there are urgent service users and there are users with the same id to be transmitted in the pre-scheduling queue of the current subframe, the urgent service users will be placed in the sending queue, and the users to be transmitted in the original pre-scheduling queue will be placed in the new data unsent queue. business users.

Among them, the users in the preemption queue replace other users with the same CCE position in the pre-scheduling queue, the replaced users are put into the new data unsent queue, and the users in the preemption queue are sent first.

Among them, if the retransmission user cannot be processed, the retransmission user is put into the retransmission failure user queue, and the retransmission frame number and subframe number are recorded, and returned to the pre-scheduling module, and the pre-scheduling module subsequently initiates adaptive retransmission.

Among them, if the emergency service is not successfully sent, it will be placed in the preempting user queue, and the users in this queue will preempt the resources of other users who meet the conditions in the subsequent processing subframes;

For users with a short SR period, preempt some or all of the new data resources of other users in the pre-scheduling queue, and place the replaced users in the new data unsent queue.

The scheduling method proposed in this application can process retransmission and new transmission services in parallel, greatly reducing the processing time of the MAC layer, enabling the system to smoothly evolve to low latency, and better meeting the low latency requirements of 5G in the future.

The present invention processes the scheduled new transmission and retransmission services in parallel, separates the user priority sorting function that occupies most of the processing amount of the MAC from the real-time processing flow, and greatly shortens the processing time of the MAC.

The method of the present invention eliminates the timing constraints between baseband processing and protocol processing, and only the processing of HARQ retransmission users that have a strong real-time relationship with the air interface will be limited by the feedback time point of the baseband, and the MAC module can be deployed more flexibly , which provides a basis for the subsequent implementation of the optimized resource allocation method, and the product can smoothly evolve to short TTI subframes.

The method of the invention can meet the QoS requirements of different types of services, open up real-time channels for sudden emergency services, better realize the global utilization of resources, and greatly reduce the link overhead of emergency services with high delay requirements. , to better meet the needs of future 5G low-latency services.

Description of drawings

1 is a flowchart of a scheduling method for 5G low-latency evolution according to an embodiment of the present invention;

2 is a flowchart of baseband uplink reception processing according to an embodiment of the present invention;

FIG. 3 is a flowchart of a process of adjusting a pre-scheduled queue according to an embodiment of the present invention.

Detailed ways

The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and embodiments. The following examples are intended to illustrate the present invention, but not to limit the scope of the present invention.

In general, this application tries to eliminate the timing constraints between baseband processing and protocol processing, and the real-time part only retains the design idea of the HARQ retransmission function that has a strong real-time relationship with the air interface, and separates the new transmission service and the retransmission service for parallel processing. , reducing the processing time of the MAC layer. For future 5G services that require low latency, open up emergency service channels in real-time processing tasks, and prioritize the preemption processing process of sending emergency services by preempting the resources of low-priority users.

Specifically, FIG. 1 shows a flowchart of a scheduling method capable of evolving to 5G low latency according to an embodiment of the present application. As shown in FIG. 1 , the method includes the following steps.

S1, the real-time process starts;

S3, perform pre-scheduling processing, receive subframes that currently need to be newly transmitted, and generate a pre-scheduling user queue;

S2, at the same time, baseband uplink reception processing includes receiving PUSCH and PUCCH channels, and generating a retransmission user queue;

S4, at the same time, receive whether an emergency service user arrives at the upper level, and obtain a low-latency alarm service;

S5, adjusting the pre-scheduled users in the scheduling queue that have been prepared for transmission, inserting emergency service users and retransmission service users into the pre-scheduled user queue, and possibly replacing the users corresponding to the newly transmitted data in the pre-scheduled queue;

S6, perform multiplexing and grouping for the users that need to be sent finally, and send the finally generated control channel and data channel to the baseband;

S7 , returning the user queue of the failed retransmission user/the user whose new data has not been successfully sent to the pre-scheduling module for rearranging; the user whose emergency service has not been successfully sent will generate a preemption queue, and continue to go through the preemption process in the next real-time processing subframe for priority sending.

S8, the process ends.

After the baseband receives the information of the control channel and the data channel, it performs reception processing. The uplink and downlink scheduling of the baseband is basically the same. FIG. 2 shows a flowchart of the baseband uplink reception processing according to the embodiment of the present application. The operation steps are described below.

S1, start;

S2, reaching the time point of receiving uplink data;

S3, whether the user data is correctly received and matches the information stored in the Hp process, if so, execute step S4, otherwise execute step S6;

S4, demultiplex the data and send it to the upper layer;

S5, release the corresponding resources and processes, and directly go to step S8;

S6, accumulating the number of transmissions in the process, and judging whether the number of transmissions reaches the maximum number of transmissions configured for the user, if so, go to step S5, otherwise go to step S7;

S7, generate a retransmission queue, and initiate retransmission processing (if the retransmission fails, the user is added to the retransmission failure queue);

S8, determine whether all users have been processed, if so, go to step S9, otherwise return to step S3;

S9, end.

For newly transmitted data, retransmitted data and urgent service data, after entering the pre-scheduled user queue, corresponding adjustment processing is required to make the transmission more efficient. FIG. 3 shows a flowchart of adjusting the pre-scheduling queue processing according to an embodiment of the present application. As shown in FIG. 3 , the specific operation steps are as follows.

S1, start processing;

S2, receiving the pre-scheduling queue result of the corresponding subframe;

S3, determine that the retransmission queue or the preemption queue is not empty;

S4, it is determined that there is a sudden emergency business;

S5, judge whether there are the same users in the pre-scheduling queue, if so, go to S6, if not, go to S7;

S6, there is a user to be transmitted with the same id in the current subframe pre-scheduling queue, replace the user and write the original pre-sent user into the new data unsent queue (if it is an SR user, the original user will not be preempted), go to S10;

S7, if there is no user to be transmitted with the same id in the pre-scheduling queue of the current subframe, judge whether there are idle resources and the number of users in the pre-scheduling queue does not exceed the maximum number of users supported by the TTI; if so, go to S8, if not, go to S9;

S8, allocate resources to the user, add the user to the sending queue, and go to S10;

S9, the retransmission is added to the retransmission failed user queue, the emergency service is sent first, and the unsuccessful emergency service is sent to the preemptive user queue;

S10, when the processing of the users in the pre-scheduling queue/preemption queue of this subframe is completed, or when the PDCCH and PDSCH resources are exhausted, go to S11;

S11, the process ends.

Wherein, in step S3, if there are retransmission users that need to be processed, and there are users with the same id to be transmitted in the current subframe pre-scheduling queue, then the to-be-transmitted users are put into the new data unsent queue, and the retransmission users are made first;

Further, if the retransmission user cannot be processed, the retransmission user is placed in the retransmission failure user queue, and the retransmission frame number and subframe number are recorded, and returned to the pre-scheduling module, which subsequently initiates adaptive retransmission.

Among them, in step S3, the uplink preempting user queue is processed (if there are users with the same id in the pre-scheduling queue, the same as step a in the first step is processed), and the users in the pre-scheduling queue can replace other users with the same CCE position in the pre-scheduling queue Users, put the replaced users into the new data unsent queue, and send the users in the preempted queue first (note that MSG3 transmission, TTIbundling users, retransmission users, and SPS service users cannot be preempted).

Among them, in step S4, if there is an emergency service (for example, there are users with the same id in the pre-scheduling queue, then processing a in the same step), and the number of users in the pre-scheduling queue reaches the maximum number of scheduling users supported by the TTI, then Put users with the same CCE position in the pre-scheduling queue of this subframe into the new data unsent queue, and send emergency services first (be careful not to preempt MSG3 transmission, TTIbundling users, retransmission users, and SPS service users).

Wherein, in step S9, if the emergency service is not successfully sent, it is put into the preempting user queue, and the users in this queue can preempt the resources of other users who meet the conditions in the subsequent processing subframe; wherein, in step S9, processing SR period<=10ms Users, that is, users with a short SR period, can go through the preemption process (equivalent to the processing of emergency services, the preemption priority is lower than that of formal emergency services), and preempt some or all of the new data resources of other users in the pre-scheduling queue, which will be replaced The user is put into the new data unsent queue; if the SR queue allocation fails, the SR user is put into the preemptive user queue.

Finally, the method of the present application is only a preferred embodiment, and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (7)

1. A scheduling method for 5G low-latency evolution, comprising: Step 1, receiving newly transmitted data in the current subframe and generating a pre-scheduled user queue, synchronously receiving retransmission service and/or emergency service data; Step 2, adjusting the pre-scheduling users in the scheduling queue, and inserting emergency service users and retransmission service users into the pre-scheduling user queue; Step 3, sending user multiplexing group packets to baseband processing according to the agreed number of users; Step 4: Return the user queue for retransmission failed users/new data unsuccessfully sent to the user queue, and users who fail to send emergency services successfully will generate a preemption queue to return; Wherein, step 2 further includes: Step 21, receiving the pre-scheduling queue result of the corresponding subframe; Step 22, it is determined that the retransmission queue or the preemption queue is not empty, or that there is a sudden emergency service; Step 23, the retransmission is added to the retransmission failure user queue, the emergency service is sent preferentially, and the failed emergency service is sent to the preempting user queue; Wherein, step 22 further includes: If there is a user to be transmitted with the same id in the current subframe pre-scheduling queue, replace the user and write the original pre-sent user into the new data unsent queue; If there is no user to be transmitted with the same id in the pre-scheduling queue of the current subframe, determine that there are idle resources and the number of users in the pre-scheduling queue does not exceed the maximum number of users supported by the TTI, allocate resources for the user, and add the user to the sending queue; Wherein, step 22 further comprises: If there is a retransmission user queue, and there are users with the same id to be transmitted in the current subframe pre-scheduling queue, the retransmission users will be put into the sending queue, and the pending users in the original pre-scheduling queue will be put into the new data unsent queue. retransmit user; If there is an uplink preempting user queue, and there are users with the same id to be transmitted in the pre-scheduling queue of the current subframe, the pre-empting users will be placed in the sending queue, and the users to be transmitted in the original pre-scheduling queue will be placed in the new data unsent queue. , but the priority is lower than the retransmission user; If there are urgent service users and there are users with the same id to be transmitted in the pre-scheduling queue of the current subframe, the urgent service users will be placed in the sending queue, and the users to be transmitted in the original pre-scheduling queue will be placed in the new data unsent queue. business users. 2. The method according to claim 1, wherein the step 2 further comprises: Based on the queue length and the number of users required by the baseband, emergency service users and retransmission service users replace users in the pre-scheduled queue corresponding to newly transmitted data. 3. The method according to claim 1, wherein the step 4 further comprises: Return the queue of users who fail to retransmit/successfully send new data to the pre-scheduling module for rearranging; users who fail to send urgent services will generate a preemption queue, and continue to go through the preemption process in the next real-time processing subframe to send first. 4. The method according to claim 1, wherein step 4 further comprises: The baseband correctly receives the multiplexed packet data and matches the information stored in the Hp process, demultiplexes the data, and sends it to the upper layer; or The baseband does not correctly receive the multiplexed packet data or does not match the information stored in the Hp process, determine that the number of transmissions has not reached the maximum number of transmissions configured for the user, generate a retransmission queue, and initiate retransmission processing; or The excess number of users is returned to the respective queues by the MAC itself. 5. method according to claim 1, is characterized in that, the user in preempting queue replaces other users that CCE position is identical in the pre-scheduling queue, will be replaced user is put into new data unsent queue, preferentially sends the preemptive queue in the queue. user. 6. method according to claim 1, is characterized in that, if retransmission user cannot be handled, then retransmission user is put into retransmission failure user queue, and the frame number subframe number of record retransmission is returned to pre-scheduling module, and the adaptive retransmission is subsequently initiated by the pre-scheduling module. 7. The method according to claim 1, wherein the emergency service is not sent successfully and then is put into a preempting user queue, and in this queue, the user preempts the resources of other qualified users in subsequent processing subframes; For users with a short SR period, preempt some or all of the new data resources of other users in the pre-scheduling queue, and place the replaced users in the new data unsent queue.

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