CN102186210A

CN102186210A - Downlink load control method for time division synchronous code division multiple access trunking system

Info

Publication number: CN102186210A
Application number: CN2011101124031A
Authority: CN
Inventors: 陈美娟; 邵世祥; 朱洪波
Original assignee: Nanjing Post and Telecommunication University
Current assignee: Nanjing Post and Telecommunication University; Nanjing University of Posts and Telecommunications
Priority date: 2011-04-29
Filing date: 2011-04-29
Publication date: 2011-09-14

Abstract

The invention discloses a downlink load control method for a time division synchronous code division multiple access trunking system, which aims at problem that the downlink of the time division synchronous code division multiple access trunking system is easy to overload. The method comprises the following steps of: first queuing groups in an overload timeslot according to the transmission power of base stations in a way that the group comprises the base station with the highest transmission power is arranged at the head of a queue; then reducing the adaptive multi-rate coding rate of the group at the head of the queue by a level, and judging whether the timeslot is overloaded currently or not; if the timeslot is overloaded currently, continuing reducing the adaptive multi-rate coding rate of the group by the level until the system is not overloaded or the adaptive multi-rate coding rate of the group is the lowest; and if the adaptive multi-rate coding rate of the group is the lowest, processing the next group in the same way until the system is not overloaded or the group at the tail of the queue is processed. In the method, the downlink load of the time division synchronous code division multiple access trunking system is controlled based on an adaptive multi-rate coding way, the method is simple to implement, and the quality of communication among the groups can be ensured.

Description

A kind of TD SDMA inserts cluster system descending duty control method

Technical field

The present invention relates to digital clustering communication system, particularly descending load control algolithm in the TD-SCDMA group system based on AMRC.

Background technology

The Digital Clustering technology was risen in the world from the mid-90 in 20th century, had obtained having used widely and having obtained good social benefit and economic benefit.In China, along with social activities and economic activity rhythm are accelerated, many professional bodies are urgent day by day to the demand of the trunking communication network that can be used for the wide area dispatch control.

At present, the digital cluster communication system that China has been ratified by the Ministry of Information Industry has four kinds at present, that is: TETRA, iDEN, GoTa and GT800.These four kinds of systems though have fairly perfect clustering functionality and business, support that the ability of high-speed multimedia business is more weak mainly all based on second generation mobile communication technology, can not adapt to the needs of following trunking communication development fully, and potentiality are relatively poor.And all also there are some problems in this four series products: because a large amount of technical patents is grasped abroad in producer's hand, system and terminal equipment price are higher; These two systems of the GoTa of domestic independent research and GT800 also can't be completely free of the control of overseas enterprise to its core patent respectively based on CDMA and GSM technology aspect patent, and slightly inadequate on follow-up increased functionality too.

TD-SCDMA is as the 3G (Third Generation) Moblie technology with China's independent intellectual property right, and through effort for many years, its research and development and industrialization work have obtained breakthrough, have begun to take shape integrated industrial chain and industrial groups, and commercial at home.

TD-SCDMA system based on the TDD technology, when carrying out PTT (putting call through immediately after connection) business, all technical capabilities that not only have 3G, the unique advantage that has other 3G especially and do not had: the asymmetric time slot allocation ability of the up-downgoing that TD-SCDMA possesses, can distribute the up-downgoing resource according to traffic carrying capacity, this group system to half-duplex operation is very useful.Simultaneously, TD-SCDMA wireless access technology as the 3GPP international standard, expand to digital cluster system on this basis with independent intellectual property right, both can further expand the application space and the inter-industry competition ability of TD-SCDMA technology, also meet Clustering developing direction and national interests development strategy fully.Group system based on TD-SCDMA, owing to be semi-duplex communication system, and descending employing broadcast mode emission, mainly take reverse link traffic channel, the called subscriber of group shares downlink data, does not have reverse link traffic channel, and main users is the same substantially with general T D-SCDMA system control mode, belong to point-to-point control, and the called subscriber belongs to the point-to-multipoint control mode.Therefore, need be according to these characteristics, design is suitable for the wireless resource management algorithm of TD-SCDMA group system.

Load control is a kind of wireless resource management algorithm, and broad research has been arranged in Cellular Networks.In trunking communication, the base station is transmitted to the power of group according to the poorest user of channel quality in group decision, and this causes the system descending overload probably.Existing load control algolithm is not suitable for the TD-SCDMA group system.Therefore, need design to be suitable for the load control algolithm of TD-SCDMA group system.

AMRC (Adaptive Multi-Rate Coding, adaptive multi-rate coding) technology is the speech coding standard that 3GPP proposes, it adjusts the code rate of AMR voice in real time according to network condition, thereby guarantee that with only speed the speech quality of voice reaches optimum, 8 kinds of AMR speed ranks of standard definition are respectively 12.2kbps, 10.2kbps, 7.95kbps, 7.4kbps, 6.7kbps, 5.9kbps, 5.15kbps and 4.75kbps from high to low.

Summary of the invention

Technical problem: the object of the invention provides a kind of Time Division-Synchronous Code Division Multiple Access and inserts cluster system descending duty control method, in the TD-SCDMA trunking communication, when descending overload, employing reduces group's transmitting power one by one based on the method for AMRC, all is reduced to minimum rank up to system's nonoverload or all AMR of group speed.This method makes system recover the normal duty state as far as possible when guaranteeing the certain service quality of group.

Technical scheme: the present invention is a kind of TD-SCDMA system descending duty control method based on AMRC, and it comprises 3 stages: group's prioritization, load down, load inspection.

TD-SCDMA group system load control mode of the present invention, it is utilization AMRC principle, begin to carry out the load down operation from the group of base-station transmitting-power maximum, rank of every reduction AMR speed, just reexamine load, algorithm finishes if load meets the demands, otherwise reduces rank of AMR speed again.This method comprises following process:

1) after detecting certain time slot overload, at first the group to this time slot carries out prioritization according to the base station transmitting power size, the base station transmitting power maximum come head of the queue, being queued at the end of queue of base station transmitting power minimum.

2) begin to carry out the load down operation from head of the queue;

3) the AMR speed to this group reduces a rank;

4) judge whether transship this moment:

If 1. nonoverload, then algorithm finishes;

If 2. overload then changes 5).

5) judge whether the AMR of this group speed arrives minimum rank:

If 1. do not arrive minimum rank, then change 3);

If 2., then change 6) to minimum rank.

6) judge whether tail of the queue:

If 1. to tail of the queue, then algorithm finishes.

If 2. do not arrive tail of the queue, then change 7).

7) queue pointer points to next group.

Beneficial effect: the present invention proposes a kind of duty control method of the TD-SCDMA of being applied to group system,, when guaranteeing the group service quality, reach the effect that reduces the total transmitting power in base station by reducing the AMR speed rank of group.

Description of drawings

Fig. 1 is a load control algolithm flow chart.

Embodiment

The present invention is based on the AMRC method, when the descending appearance of TD-SCDMA group system was transshipped, implementing the present invention can make system loading return to normal condition under the situation that guarantees the group communication quality.The present invention includes three phases:

1) group's priority queueing.Group is according to the queuing of the size of base station transmitting power, the transmitting power maximum come head of the queue, being queued at the end of queue of transmitting power minimum;

2) load down.Begin to reduce the AMR speed of group from head of the queue, rank of AMR speed of certain group falls in every execution load down exactly.When arriving minimum rank, certain group's AMR speed changes next group.

3) load is checked.After the operation of AMR speed once falls in every execution, just calculate the system loading of this moment,, otherwise continue to carry out the operation of falling AMR speed if meet the demands then algorithm stops.

The present invention is described in further detail below in conjunction with accompanying drawing:

Fig. 1 may further comprise the steps:

101, in the group of overload in the time slot, line up from big to small according to base station transmitting power, the transmitting power maximum come head of the queue, being queued at the end of queue of transmitting power minimum;

When 102, algorithm begins, the head of the queue of pointed group formation;

103,, reduce rank of its AMRC speed to the group of pointed;

104, the pointer indication AMRC of group is reduced a rank, recomputate the power that base station is given each group;

105, judge the maximum transmission power that this moment, whether base station transmitting power allowed greater than the base station.If greater than, then system overload changes step 106; If less than, then nonoverload changes step 109;

If 106 systems also transship, judge then whether the AMRC speed of this group arrives minimum rank.If do not arrive minimum rank, then change step 104; If arrived minimum rank, then change step 107;

107, judge that pointer is whether to the tail of the queue of group's formation.If do not arrive tail of the queue, then change step 108; If arrived tail of the queue, then change step 109;

108, adjust pointer, point to next group, change step 103 then.

109, finish.

Claims

1. a TD SDMA inserts cluster system descending duty control method, it is characterized in that this method reduces the power that base station is given each group based on adaptive multi-rate coding AMRC, and each group is implemented the operation of reduction of speed rate successively; Specifically comprise the steps:

1) during certain time slot overload, the group in this time slot is lined up from big to small according to base station transmitting power, the transmitting power maximum come the formation first place;

2) pointed head of the queue, load down are handled from head of the queue;

3) group to pointed reduces rank of its adaptive multi-rate coding;

4) judge this moment, whether time slot transshipped:

If 1. nonoverload, then algorithm finishes;

If 2. still transship, then change 5);

5) group of judgement pointed, whether its adaptive multi-rate coding arrives minimum rank:

If 1. arrived minimum rank, then changeed 6);

If 2. do not arrive minimum rank, then change 3);

6) judge whether pointer points to tail of the queue:

If 1. arrived tail of the queue, then algorithm finishes;

If 2. do not arrive tail of the queue, then change 7);

7) pointer moves down, and points to next group, changes 3).

2. TD SDMA as claimed in claim 1 inserts cluster system descending duty control method, it is characterized in that: in the described step 3), and every execution in step 3) once, reduce rank of group's adaptive multi-rate coding of pointed exactly.

3. TD SDMA as claimed in claim 1 inserts cluster system descending duty control method, it is characterized in that:

In the described step 5), when the adaptive multi-rate coding speed of certain group was reduced to lowermost level, system still transshipped, then next group in the processing queue.