CN1225929C - Radio interface method of mobile communication system - Google Patents

Abstract

The present invention provides a wireless interface method of a mobile communication system. The method comprises the steps that the frame length of fixed wireless frames is determined; the wireless frames are classified in a multi-frame range; physical channels of different attributes are respectively mapped to the wireless frames of different classifications; the number of the wireless frames of different classifications in one multi-frame are set according to application environments. By the present invention, the complexity of a resource allocation algorithm in a data voice system can be simplified, and the cost of the data voice system providing high-speed data can be reduced.

Description

A wireless interface method in a mobile communication system

technical field

The present invention relates to a mobile communication system, in particular to the field of wireless interface technology in the mobile communication system.

technical background

The mainstream technology of the third-generation mobile communication system (3G): WCDMA technology and CDMA2000 technology, both use the fixed-length frame structure as the basic transmission unit, and implement rate matching, convolution error creation, interleaving operations and other operations on one frame .

The resources of the radio interface are all allocated based on the radio frame, that is, each physical channel has a fixed mapping relationship with the radio frame. Take WCDMA as an example:

The WCDMA basic spreading code rate is 3.84Mcps, the frame length is 10ms, each frame contains 15 time slots, and each time slot has 2560 Chips.

Only the dedicated channel of WCDMA is introduced below.

(1) Uplink

The uplink dedicated physical channel is divided into: a dedicated physical data channel (DPDCH) and a dedicated physical control channel (DPCCH).

Dedicated physical data channel: The uplink dedicated physical data channel is used to carry the dedicated data of the second layer and higher layers.

Dedicated physical control channel: used to carry the control information generated by the first layer, including: pilot signal (Pilot), power control signal (TPC) and transport format indicator bit (TFI) for channel estimation.

The frame structure of the uplink dedicated physical channel is shown in Figure 1 . Each frame is 10ms, divided into 15 time slots. 72 connected frames form a superframe with a duration of 720ms.

The number of bits per time slot is: 10*2k, where k=0, . . . , 6, and the corresponding SF=256/2k. That is 256-4. DPCCH and DPDCH are sent in parallel.

(2) Downlink

The downlink dedicated physical channel is divided into: a dedicated physical data channel (DPDCH) and a dedicated physical control channel (DPCCH).

The downlink dedicated physical channel is time division multiplexing of DPCCH and DPDCH. The data of the second layer and the upper layer and the control information (TPC, TFI, Pilot) of the first layer are multiplexed on the same channel through time division multiplexing. Its frame structure is shown in Figure 2.

Similarly, a downlink DPCH frame is also composed of 15 time slots, and the frame length is 10ms. 72 consecutive frames form a superframe.

When the total bit rate is greater than the maximum code rate that a physical channel can carry, a multi-code transmission method can be used, that is, multiple parallel identical physical channels are sent in the downlink. At this time, the layer-1 control information only needs to be sent on the first physical channel, and other physical channels do not send any information in a corresponding time period.

Another method of multi-code transmission is that each transmitted physical channel has a different spreading gain. Therefore, at this time, each physical channel needs to send the control information of the first layer.

From the above, there is a fixed mapping relationship between the physical channel and the wireless frame of WCDMA and CDMA2000, even in the subsequent evolution process.

The biggest advantage of the third-generation mobile communication system compared with the second-generation mobile communication system is that it can provide high-speed data services. The evolution of WCDMA and CDMA2000 is also marked by the data service rate (mainly referring to downlink) provided.

Because the QOS requirements of voice services and data services differ greatly, it is difficult to jointly optimize them in a system. In other words, a wireless system provides high-speed data services and voice services at the same time, and it is difficult to optimize the utilization of wireless resources. Therefore, the evolution of CDMA2000 is divided into two stages:

The first stage: CDMA2000 1xEV-DO (Data Only) uses a channel separated from voice to transmit data. The HDR (High Data Rate) technology proposed by Qualcomm has become the technical standard of this stage, supporting an average rate of 650kbps and a peak rate of 2.4 Mbps high-speed data services.

HDR is a CDMA wireless communication technology that is optimized for packet data services and has high spectrum efficiency. It can provide high-speed data transmission services with a peak rate of 2.4Mbps within a 1.25M bandwidth. This rate is even higher than the data rate that WCDMA can provide within 5M bandwidth. HDR adopts the technology of TDM, and the analysis proves that TDM is more suitable for the transmission of data services. Due to the limitations of the current application of the DO system, it will inevitably transition to the second stage.

The second stage: cdma2000 1xEV-DV (Data and Voice), the data channel and the voice channel are integrated, and 1XEV-DV can provide a throughput of 3.1M or even higher.

1xEV-DV adds a new traffic channel (Forward Packet Data Channel, F-PDCH) on the basis of CDMA2000, and uses both CDM and TDM schemes for F-PDCH resource allocation, plus On top of other wireless resource resource scheduling schemes of the forward channel that originally existed, the allocation of wireless resources is more complicated, and the system processing burden is greatly increased.

In the evolution process of WCDMA, the High Speed Data Packet Access (HSDPA) technology was proposed. Using the PDSCH channel can provide up to 8M service rate. Like CDMA2000 1xEV-DV, this system provides high-speed data and voice services at the same time, which inevitably leads to wireless The resource allocation algorithm is extremely complex.

Contents of the invention

The purpose of the present invention is to propose a wireless interface method in a mobile communication system, which can simplify the complexity of the resource allocation algorithm in the data voice system and reduce the cost of the data voice system providing high-speed data.

A wireless interface method in a mobile communication system, comprising the following steps:

a. Determine the fixed wireless frame length;

b. Classifying the radio frame within the multiframe range, wherein the multiframe is composed of a plurality of radio frames;

c. Physical channels with different attributes are mapped to different types of wireless frames;

d. The number of different types of radio frames in a multiframe is set according to the application environment.

The different types of wireless frames may adopt different wireless resource allocation and scheduling schemes, wherein the wireless resource allocation scheme is to divide resources by time or divide resources by code, and the scheduler is to perform scheduling by time or by code for scheduling.

The radio frames of different types may adopt the same or different frame structures.

Different time slot structures may be used in the different frame structures.

Adoption of the present invention greatly simplifies the complexity of the resource allocation algorithm in the data voice system, reduces the cost of the data voice system providing high-speed data, and is a technical enhancement to the existing wireless interface design scheme.

Description of drawings

FIG. 1 is a schematic diagram of a frame structure of an uplink DPDCH/DPCCH;

FIG. 2 is a schematic diagram of a downlink DPCH frame structure;

Fig. 3 is a schematic diagram of wireless frame classification according to the present invention.

Detailed ways

The specific implementation manner of the present invention will be described below in conjunction with the accompanying drawings.

Firstly, the frame length of the wireless frame is designed according to the needs. For example, in the WCDMA system, the frame length of the wireless frame is set as 10ms, and the chip rate is set as 3.84Mcps.

Wireless frames can be classified within the range of multiframes according to certain principles, such as classifying wireless frames by odd and even frames, and the number of these two types of frames is the same, as shown in Figure 3.

Physical channels with different attributes can be mapped to different types of radio frames respectively. Assume that the common physical channel and physical signaling of the cell is physical channel A, the physical channel for transmitting voice services is physical channel B, and the physical channel for transmitting data services is physical channel C. Physical channels A and B can be mapped to even frames, and physical channel C Can be mapped to odd frames.

Different types of radio frames may use different radio resource allocation and scheduling schemes. The physical channel that bears the voice service is more suitable to adopt the technical scheme of CDM, and the physical channel that bears the weight of the data service is more suitable to adopt the technical scheme of TDM.

In this embodiment, it can be seen from the physical channel mapping relationship in the previous step that the even-numbered frames carry the physical channels A and B, adopt the technical solution of CDM (same as the solution of the IS-95 system), and the odd-numbered frames carry the physical channel C. Adopt the technical solution of TDM (same as the solution of CDMA2000 1X EV DO system).

Different types of wireless frames may adopt the same or different frame structures, and time slot designs in different frame structures may also adopt different design schemes. For example, the odd frame adopts 15 time slots, and the even frame can adopt the structure of 16 time slots. The time slot structure can also be further designed as required. In this embodiment, the odd and even radio frames adopt the same frame structure, which is 15 time slots, which is the same as that of the WCDMA system.

The above points are integrated together to complete the design of a wireless interface. Because the even-numbered frames only handle the scheduling of common channel resources and voice service resources, the CDM method is adopted; while the odd-numbered frames only process data services, the TDM method is used. In the processing of this system, two relatively simple resource scheduling algorithms are used in time-sharing. However, the current mobile DV system that provides high-speed data services simultaneously processes voice and data services with very different business attributes, so the allocation and scheduling of wireless resources is extremely complicated (such as using CDM and TDM at the same time), and the system processing burden is heavy. . Therefore, by adopting the design scheme in the present invention, the allocation and scheduling of radio resources of the system will become relatively simple, and the cost of the system will be greatly reduced.

The present invention can also provide the function of wireless frame classification setting, that is, the number of different types of wireless frames in a multiframe can be set according to needs, so as to adapt to different application environments.

In this embodiment, the number of radio frames of the two attributes is 1:1. It can be set to a corresponding ratio according to the actual application occasion. For example, if a region mainly uses voice services, it can be set to 3:1; if it is mainly used for data services, it can be set to 1:3.

A special case of the present invention is that there is only one category, that is, no radio frame is classified, which is the same as the existing mobile system radio interface design scheme.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person familiar with the technology can easily think of changes or replacements within the technical scope disclosed in the present invention. , should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (4)

1. A wireless interface method in a mobile communication system, characterized in that it comprises the following steps: a. Determine the fixed wireless frame length; b. Classifying the radio frame within the multiframe range, wherein the multiframe is composed of a plurality of radio frames; c. Physical channels with different attributes are mapped to different types of wireless frames; d. The number of different types of radio frames in a multiframe is set according to the application environment. 2. A wireless interface method in a mobile communication system according to claim 1, characterized in that: said different types of wireless frames can adopt different wireless resource allocation and scheduling schemes, wherein said wireless resource allocation scheme For dividing resources by time or by code, the scheduling scheme is scheduling by time or by code. 3. A wireless interface method in a mobile communication system according to claim 1 or 2, characterized in that the wireless frames of different types can adopt the same or different frame structures. 4. A wireless interface method in a mobile communication system according to claim 3, characterized in that: different time slot structures can be used in the different frame structures.