CN107567097A - A kind of resource allocation methods of down control channel - Google Patents

Abstract

This application discloses a kind of resource allocation methods of down control channel, including：Starting resource block (RB) sequence number of frequency domain bandwidth according to shared by channel circumstance selects down control channelThe frequency domain for indicating (CFI) indicating downlink control channel with control format originates RB sequence numbersUsing technical scheme disclosed in the present application so that the control resource allocation of ultrashort t TI frame structure systems possesses feasibility, and more flexible and efficient.

Description

A resource allocation method for downlink control channel

technical field

The present application relates to the technical field of mobile communication, in particular to a resource allocation method of a downlink control channel.

Background technique

In recent years, wireless communication technology has developed rapidly, and modern society has entered the information age. All kinds of communication technologies are moving towards the goal of "high speed, low delay", and the increasingly stringent requirements for delay have also been clearly written into the design standards of various communication technologies. The low-latency and high-reliability scenario of 5G clarifies the performance index requirement of air interface delay of 1 ms, which means that a new frame structure needs to be designed to make the air interface transmission time interval (TTI) short enough. At present, regarding the design of new frame parameters, the widely recognized research direction is to retain the original LTE subcarrier spacing, cyclic prefix (CP) length, and change the number of symbols per subframe, thereby minimizing the basis for changes to the LTE system On, to achieve 5G and LTE compatible design.

In order to meet the needs of 5G low-latency and high-reliability scenarios, it is necessary to design an ultra-short TTI frame structure. The ultra-short TTI frame structure needs to retain the original LTE subcarrier spacing and CP length, and the length of each subframe is one symbol or two symbols. . In an ultra-short TTI frame structure system, if the downlink control channel occupies one or several symbols alone, it will cause a large system overhead. For example, in extreme cases, if each subframe contains only one symbol, the downlink control channel must be reconsidered. Resource allocation strategy for channels and traffic channels. Therefore, the low-latency and high-reliability scenario of 5G cannot directly follow the downlink control channel resource allocation strategy of the 4G LTE system, and must be redesigned.

Contents of the invention

The present application provides a resource allocation method for a downlink control channel, which makes the control resource allocation of the ultra-short TTI frame structure system feasible and more flexible and efficient.

The present application discloses a resource allocation method for a downlink control channel, including:

Select the starting resource block RB sequence number of the frequency domain bandwidth occupied by the downlink control channel according to the channel environment

Use the control format to indicate CFI to indicate the frequency domain start RB number of the downlink control channel

Preferably, the bandwidth occupied by the downlink control channel is The system bandwidth is

in:

is the number of subcarriers contained in each RB;

is the number of RBs occupied by the physical downlink control channel PDCCH, which is set according to the system bandwidth and system requirements;

is the number of RBs contained in the downlink bandwidth.

Preferably, the base station side selects the starting RB sequence number of the frequency domain bandwidth occupied by the downlink control channel according to the channel environment

It can be seen from the above technical solution that the resource allocation method of the downlink control channel provided by the present application selects the starting resource block (RB) sequence number of the frequency domain bandwidth occupied by the downlink control channel according to the channel environment And use the Control Format Indicator (CFI) to indicate the frequency domain start RB sequence number of the downlink control channel It makes the control resource allocation of the ultra-short TTI frame structure system feasible and more flexible and efficient.

Description of drawings

FIG. 1 is a schematic diagram of downlink control channel resource allocation in the present invention.

detailed description

In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and examples.

The present invention proposes a new downlink control channel resource allocation strategy based on the requirement of a new subframe structure in a low-latency high-reliability scenario of 5G. Different from the time-domain allocation scheme of the 4G LTE system, the present invention adopts a frequency-domain allocation scheme, which limits the downlink control channel to be transmitted within a specified bandwidth.

The downlink control channel resource allocation scheme proposed by the present invention is shown in Figure 1, and the system bandwidth is The bandwidth occupied by the control channel is in:

is the number of subcarriers contained in each resource block (RB);

is the number of RBs occupied by the physical downlink control channel (PDCCH), which is set according to the system bandwidth and system requirements;

is the number of RBs contained in the downlink bandwidth;

is the starting RB sequence number of the downlink control channel;

N _S is the number of OFDM symbols included in each TTI, and TTI is the transmission time interval.

In order to combat frequency selective interference, the base station side can select the starting RB sequence number of the frequency domain bandwidth occupied by the downlink control channel according to the channel environment And use the control format indicator (CFI) to indicate the frequency domain start RB sequence number of the control channel

Taking the system bandwidth as 20M and the control channel occupied bandwidth as 5M as an example, the control channel resource configuration list can be obtained as shown in Table 1:

Table 1 Example of control channel resource configuration list

Using the above scheme, the control resource allocation of the ultra-short TTI frame structure system is feasible and more flexible and efficient.

The above is only a preferred embodiment of the application, and is not intended to limit the application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the application should be included in the application. within the scope of protection.

Claims (3)

1. A kind of 1. resource allocation methods of down control channel, it is characterised in that including：

   The starting resource block RB sequence numbers of frequency domain bandwidth according to shared by channel circumstance selects down control channel

   RB sequence numbers are originated with the frequency domain of control format instruction CFI indicating downlink control channels
2. 2. according to the method for claim 1, it is characterised in that：

   The down control channel is shared with a width ofSystem bandwidth is

   Wherein：

   It is the subcarrier number contained by each RB；

   It is the RB numbers that physical downlink control channel PDCCH takes, is set according to system bandwidth and system requirements；

   It is the RB numbers contained by downlink bandwidth.
3. 3. according to the method for claim 2, it is characterised in that：

   The starting RB sequence numbers of base station side frequency domain bandwidth according to shared by channel circumstance selects down control channel