CN1450744A - Media insertion control method for multimedia broadband CDMA system - Google Patents

Abstract

The invention provides a medium access control method for a multimedia broadband code division multiple access system, comprising the steps of: dividing various services with different parameters into time delay sensitivities according to different requirements of the services on time delay sensitivity Two services with high and low delay sensitivity are respectively connected to the system to wait for different processing; access control is performed on services with high delay sensitivity, and access to the service as much as possible according to the current system resource occupancy service users, and reserve sufficient resources for them; all services that are not sensitive to delay are accessed and placed in the buffer to wait for transmission; using the bandwidth reserved for services with high delay sensitivity will have the same or similar The same kind of business guaranteed by the maximum bit error rate is put into the same time slot for real-time transmission; using unreserved resources and resources unused by current high-delay-sensitive services, select services with low delay-sensitivity The service with the maximum carrier-to-interference ratio is sent in packets; the block error judgment is performed for the service with low delay sensitivity transmitted in the same time slot as the service with high delay sensitivity.

Description

A medium access control method for multimedia wideband code division multiple access system

technical field

The invention relates to a medium access control method applicable to a multimedia broadband code division multiple access system.

Background technique

With the continuous expansion and development of mobile service applications, the next generation of wireless cellular communication will be a mixed transmission of voice, data, video and other services with different performance parameters. The traditional voice-based Media Access Control (MAC) protocol cannot well meet the needs of future business diversity due to its singleness of business. Therefore, a new MAC protocol is needed to achieve the best utilization of system resources while taking into account service fairness as much as possible. This has become a basic problem to be faced in multimedia mobile communication systems.

In the third-generation mobile communication single-voice system, power control is usually used to keep the signal power received at the base station at an approximately constant value to overcome the near-far effect introduced by the code division multiple access system. If the traditional power control method of voice CDMA is still used under multimedia service conditions, the system capacity will be limited by the service with the minimum bit error rate (BER) due to the influence of multimedia service characteristics on the power control target value. In this way, simultaneous scheduling and transmission of voice and data services will cause serious waste of system resources. To solve the limitations of traditional closed-loop power control in multimedia applications, it can be achieved by assigning different power control targets to different services. but. Such a power control scheme entails a substantial increase in implementation complexity. The WISPER algorithm proposes to transmit packets with the same and similar BER requirements in the same time slot, so that the traditional power control scheme with only one power control target value can be continued in a time slot, compared to other same time slots The power control scheme with multiple target values in is easier to implement. However, due to the introduction of multiple iterative operations in the scheduling process, the complexity of the operation is greatly increased, so its achievability is low.

Contents of the invention

Aiming at the problems existing in the prior art, the present invention provides a medium access method suitable for a multimedia code division multiple access system, thereby obtaining higher system throughput while ensuring transmission quality.

The medium access control method for the multimedia broadband code division multiple access system of the present invention comprises the steps:

According to the different requirements of the business on the delay sensitivity, various services with different parameters are divided into two types of services with high delay sensitivity (GB) and low delay sensitivity (BE), and they are respectively connected to the system for waiting different treatment;

Perform access control for services with high delay sensitivity, access the service users as much as possible according to the current system resource occupancy, and reserve sufficient resources for them;

All services that are not sensitive to delay are accessed and placed in the buffer to wait for transmission;

Utilize the bandwidth reserved for services with high delay sensitivity, put the same kind of services with the same or similar maximum bit error rate guarantee into the same time slot for real-time transmission;

Utilize the unreserved resources and the unused resources of the current high-delay-sensitive business, select the business with the largest carrier-to-interference ratio among the low-delay-sensitive services for packet transmission;

Block error judgment is performed for services with low delay sensitivity transmitted in the same time slot as services with high delay sensitivity.

In the present invention, by dividing the business into high-delay-sensitive business and low-delay-sensitivity business and processing them separately, not only the bandwidth is guaranteed for the high-delay-sensitivity business, but the optimal system performance can be obtained, and the time The unoccupied resources of high-delay-sensitivity services send low-delay-sensitivity packets as much as possible, thus achieving the best system throughput.

Description of drawings

Fig. 1 shows the block diagram that realizes the access control method of the present invention;

Fig. 2 shows the comparison of the service throughput of the inventive method and the existing WISPER method;

Fig. 3 shows the comparison of packet error rate between the method of the present invention and the existing WISPER method.

Detailed ways

The access control method of the present invention will be described below in conjunction with the accompanying drawings.

Fig. 1 shows a block diagram for realizing the medium access control method of the present invention. Firstly, classify the various services that will be connected to the multimedia broadband code division multiple access system, and these services have different delay parameters and bit error rate requirements. In the method of the present invention, according to the different requirements of the business on the time delay sensitivity, various services with different parameters are divided into two types of business with high time delay sensitivity (GB) and low time delay sensitivity (BE). They are respectively connected to the system to wait for different processing.

Then, access control is performed on services with high delay sensitivity, and according to the current system resource occupancy, as many users of this service are accessed as possible, and sufficient resources are reserved for them. Moreover, for the GB service, the service with the highest delay sensitivity is first accessed, and then accessed in sequence from high to low delay sensitivity. And it is a resource reservation mode that allocates enough system resources to the accessed GB services and reserves them until the services leave the system.

All services that are not sensitive to delay are accessed and placed in the buffer to wait for transmission.

Utilize the bandwidth reserved for services with high delay sensitivity, put the same kind of services with the same or similar maximum bit error rate guarantee into the same time slot for real-time transmission.

In the present invention, the resources reserved for services with high time-delay sensitivity only occupy a part of system resources, and services with high time-delay sensitivity do not necessarily use all the reserved resources. Therefore, services with low delay sensitivity can use unreserved resources and reserved resources not used by current high delay sensitive services, and select the service with the largest carrier-to-interference ratio among the services with low delay sensitivity Carry out packet transmission, and then send sequentially according to the order of carrier-to-interference ratio from high to low.

For services with low delay sensitivity, when the sending time slot is empty, the number of packets that users can send in each time slot is: Under the condition of ensuring the QoS requirements of low delay sensitivity services, each time slot The maximum number of packets that can be sent. If the sending time slot is not empty, it means that the time slot is also used to send services with high delay sensitivity. At this time, the number of packets that the user can send in this time slot is: the maximum number of packets of GB services allowed to be sent in this time slot The difference from the number of GB service packets that have been sent in this time slot.

Subsequently, a block error judgment is performed on the BE service transmitted in the same time slot as the GB service, and retransmission is performed on the BE service in which transmission errors are detected until it succeeds. However, for BE services sent in empty time slots according to the QoS parameters of BE packets, block error judgment is not necessarily required.

In a preferred embodiment of the present invention, for a time slot in which GB and BE services are simultaneously transmitted, block error judgment is performed on the BE service according to the packet error rate of the GB service transmitted in the time slot.

In the method of the present invention, the capacity of the multimedia code division multiple access system is measured by the maximum number of packets that can be sent in each time slot under the condition of ensuring the quality of service (QoS) requirements of different services.

In the preferred embodiment of the present invention, a specific method of how to transmit services with high delay sensitivity in real time is also described.

First calculate the priority of each specific business in the GB business

Here φ _β (t) represents the priority of the β batch of packets at time t, that is, the number of time slots that will be allocated to the user in the next frame, P _β (t) represents the current number of packets in the β batch of packets, F _β ( t) represents the current remaining survival time of the β batch of packets under the maximum allowable delay guarantee, M _n represents the maximum number of packets that can be transmitted simultaneously in one time slot of user n, and N _p represents the number of time slots in a frame. Sort these calculated priorities from high to low p ₁ , p ₂ ...p _M (p ₁ ＞p ₂ ＞…＞p _M ), send the highest priority group first, and send the priority if there are resources left The next highest grouping, and so on. Then, put the same kind of business with the same or similar maximum bit error rate guarantee into the same time slot for real-time transmission.

Figure 2 and Figure 3 of the present invention respectively show the comparison of service throughput and packet error rate between the method of the present invention and the existing WISPER method. It can be seen from Fig. 2 and Fig. 3 that the throughput and packet error rate of the CDMA system can be obviously improved by adopting the method of the present invention.

Although the present invention has been described with reference to the preferred embodiments, those skilled in the art can make various modifications and substitutions to the present invention without departing from the spirit and scope of the present invention by referring to the illustrated embodiments and the accompanying drawings. Therefore, these modifications and replacements should fall within the protection scope of the present invention.

Claims (9)

1. media access control method that is used for the multimedia broad band code division multiple access system comprises step:

(1) according to the different requirements of business to time delay sensitivity, the miscellaneous service that will have a different parameters is divided into the high and time delay sensitivity of time delay sensitivity and hangs down two kinds of business, with they respectively connecting system to wait for different processing;

(2) the high business of time delay sensitivity is carried out access control, the situation that takies according to current system resource inserts this service-user as much as possible, and reserves enough resources for it;

(3) the insensitive business of time delay is all inserted, it is medium to be sent to put into buffer;

(4) be utilized as the high professional bandwidth of being reserved of time delay sensitivity, will have business of the same race that same or similar maximum bit error rate guarantees and put into same time slot and carry out real-time Transmission;

(5) utilize resource and the high professional untapped reserved resource of current time delay sensitivity that is not reserved, the business of selecting to have max carrier to interference in the low business of time delay sensitivity divides into groups to send;

(6) for missing the piece judgement with the low business of the high professional time delay sensitivity that in same time slot, transmits of time delay sensitivity.

2. according to the condition that the process of claim 1 wherein in service quality (QoS) demand that guarantees different business, the largest packet number that each time slot can send is weighed the capacity of this multimedia bitstream division multiple access system.

3. according to the process of claim 1 wherein in step (2), at first the highest business of access delay susceptibility inserts successively according to time delay sensitivity high order from high to low then.

4. according to the process of claim 1 wherein in step (2), to the enough system resource of the high traffic assignments of time delay sensitivity that inserted and the resource reservation mode when remaining to this business and leaving system.

5. according to the method for claim 1, wherein for the insensitive business of time delay, the packet count that each time slot of user can send is: if this time slot for empty, then is under the demand condition of the QoS that guarantees the insensitive business of time delay, and the largest packet number that each time slot can send; If this time slot is not empty, allow the largest packet number of the GB business that sends and the difference of the GB traffic packets number that this time slot had sent already for this time slot.

6. according to the method for claim 1, wherein in step (5), according to the high professional quantity of current time delay sensitivity in each time slot and the number of packet that every time slot can pass at most when sending this business, the high professional untapped reserved resource of definite resource that is not reserved and current time delay sensitivity, the carrier/interface ratio of the low traffic packets of calculation delay susceptibility, utilize the preferential transmission of surplus resources to have max carrier to interference user's grouping, send successively according to carrier/interface ratio order from high to low again.

7. according to the method for claim 1,, the low business of the time delay sensitivity in this time slot is missed the piece judgement according to the high professional mistake packet rate of time delay sensitivity that this time slot sends to the high professional and low professional time slot of time delay sensitivity of while transmission delay susceptibility.

8. according to after the mistake piece judgement that the process of claim 1 wherein in step (6), transmit until success again sending the low business of wrong time delay sensitivity.

9. according to the process of claim 1 wherein that the time delay sensitivity for sending according to the low qos parameter that divides into groups of time delay sensitivity is low professional in empty slot, need not the mistake piece and adjudicate.

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