CN101056156B - A channel quality feedback method and its user terminal and system - Google Patents

Abstract

The present invention provides a channel quality feedback method and user terminals and a system including a base station and user terminals. The base station also includes a sub-carrier dividing module for dividing the whole frequency band into N sub-bands (N is a positive integral bigger than 1), and a major-minor sub-band allocating module for allocating the main frequency sub-band and the minor frequency sub-band to each cell for communication; the base station communicates with the user terminals according the sub-band division and the allocating information and the base station also includes a determining module of the sub-band using for determining that the user terminal uses at least one of the main frequency sub-band and the minor frequency sub-band; the user terminal also includes a sub-band using information generating module for generating the sub-band using information of the corresponding user terminal and transmitting the information to the a channel quality feedback module for sending back the channel quality information to the base stations according to the sub-band using information.

Description

A channel quality feedback method, user terminal and system thereof

technical field

The invention relates to wireless communication technology, in particular to a channel quality feedback technology in a frequency multiplexing system.

Background technique

Wireless communication systems are usually distinguished by geographical areas, and each communication area in the wireless communication system may be called a cell (cell), such as a cellular wireless communication system.

In order to improve the capacity and spectrum efficiency of broadband wireless communication systems, some multi-carrier technologies have been developed. The basic idea is to divide a broadband carrier into multiple sub-carriers and transmit data on multiple sub-carriers simultaneously. In the application, the width of the subcarrier is required to be smaller than the coherent bandwidth of the system channel, so that the fading on each subcarrier is flat fading, which can reduce the crosstalk between symbols, and does not require complex channel equalization, which is suitable for high-speed data transmission. There are many forms of multi-carrier technology, such as Orthogonal Frequency Division Multiplexing (OFDM, Orthogonal Frequency Division Multiplexing), Multi-Carrier CDMA (MC-CDMA, Multicarrier-Code Division Multiple Access), Multi-Carrier Direct Spread CDMA (MC-DS- CDMA, Multicarrier-Direct Sequence-Code Division Multiple Access), multi-tone CDMA (MT-CDMA, Multitone-Code Division Multiple Access), multi-carrier TDMA (MC-TDMA, Multicarrier-Time Division Multiple Access), two-dimensional time-frequency domain Extension, and various extension technologies based on the above.

OFDM technology is a relatively representative technology in multi-carrier technology. This technology divides a given channel into many orthogonal sub-channels in the frequency domain and allows the sub-carrier spectrum to partially overlap, as long as the sub-carriers are mutually orthogonal. The data signal can then be separated from the aliased subcarriers.

In order to effectively utilize limited spectrum resources, communication networks usually reuse frequency resources in different geographical locations. As shown in Figure 1, it is a schematic diagram of the frequency reuse of a cellular network with a frequency reuse factor of 1. The pentagonal block diagram represents the cell, and the gray represents the frequency 1 used. As shown in the figure, each cell of the cellular network uses the same Frequency 1 transmits data. Although the multiplexing method with a frequency reuse factor of 1 can make good use of limited spectrum resources, for a network with a frequency reuse factor of 1, user terminals at the cell edge will be interfered by their neighboring cells, so cell edge users The signal-to-interference ratio of the terminal will be reduced, therefore, some technologies need to be adopted to improve the cell-edge signal-to-interference ratio.

The easiest way to improve the SIR at the cell edge is to increase the frequency reuse factor. As shown in Figure 2, it is a schematic diagram of the frequency reuse of a cellular network with a reuse factor of 3. The frequency is divided into three sub-frequency: frequency 1, 2, 3. For the cellular network, a reuse factor of 3 can ensure that the frequencies used by any two adjacent cells are different, but its disadvantage is that each cell can only use 1/3 of the original frequency.

Therefore, in order to further improve the efficiency of spectrum utilization, a frequency soft reuse technology has been developed. The main idea is to use a frequency reuse factor greater than 1 for the edge of the cell where the interference is more serious, and use a frequency of 1 for the inside of the cell. multiplexing factor.

Specifically as shown in Figure 3, taking the example of a multiplexing factor of 3, all subcarriers in the multi-carrier system are divided into frequencies according to a multiplexing factor of 3, and three main subcarriers are obtained: main frequencies 1, 2, 3, As shown in the article in Figure 3, each cell obtains its own primary frequency; for a specific cell, a frequency other than the primary frequency obtained is used as its secondary frequency, for example, for cell 1, the primary frequency 2 , 3 is a sub-frequency in cell 1, the primary sub-carrier is mainly used for communication at the edge of the cell, and the secondary sub-carrier is mainly used for communication inside the cell.

In order to avoid the disadvantages of the frequency multiplexing method shown in Figure 2, it is usually necessary to limit the transmit power of the main frequency and the sub-frequency. Generally, the transmit power threshold of the main frequency is higher than that of the sub-frequency. If the transmit power of the primary frequency and the secondary frequency are the same, then soft multiplexing degenerates into a multiplexing factor of 1. In addition, from the perspective of the active area of the main frequency and the secondary frequency, when the active area of the secondary frequency is 0, it is equivalent to general frequency reuse; when the active area of the secondary frequency is the entire cell, it is equivalent to a reuse factor of 1.

However, regardless of the frequency reuse method adopted by the communication system, the fading of the wireless channel is usually frequency-selective, that is, at a certain moment, the fading of a certain user terminal on a subcarrier within the relevant bandwidth can be considered as The same, but the fading on farther subcarriers cannot be considered the same, and the fading of different user terminals is usually different. Therefore, if the base station can know the fading value of each user terminal on each subcarrier, then the base station can select subcarriers with better conditions for different user terminals to transmit data as much as possible based on a certain scheduling criterion, so that most of the The propagation conditions of the user terminals are relatively good, realizing multi-user terminal diversity gain and improving spectrum efficiency. Since fading is time-varying, the allocation of subcarriers needs to be updated continuously, which is a so-called frequency scheduling technique.

In order to realize the diversity gain of multi-user terminals through scheduling in the frequency domain, the transmitting end must know the instantaneous fading values of all user terminals on all subcarriers. For the FDD system, since the uplink and downlink are not in the same frequency band, the fading of the uplink and downlink is different, so the receiving end must feed back the channel information to the sending end through another reverse link. The OFDM time-frequency resources occupied by the feedback of the channel quality indicator should be as small as possible, so as to reserve as much time-frequency resources as possible for user terminal data.

Considering that the subcarriers in the coherent bandwidth have approximate fading values, some adjacent subcarriers can be divided into a subband, and the receiving end can feed back a signal quality indicator for each subband within a certain period of time, while Feedback does not have to be done for every subcarrier. As shown in Figure 4, it is a schematic diagram of an OFDM system with 16 subcarriers. Four adjacent subcarriers are divided into a subband, so that an OFDM system with 16 subcarriers can be divided into 4 subbands: subband 1. Subband 2, Subband 3, Subband 4. Within a certain period of time, usually one TTI, only 4 channel quality indicators need to be fed back, that is, the channel quality of sub-bands 1, 2, 3, and 4 is fed back, instead of the channel quality of 16 sub-carriers, which greatly reduces Feedback overhead. The width of the above sub-bands requires a small coherent bandwidth to obtain better multi-user terminal diversity gain.

If the user terminal UE (User Equipment) feeds back all subbands, as shown in Figure 5, a schematic diagram of the channel quality at a certain moment with 12 subbands, the 12 subbands shown in the figure feed back each The channel quality of the sub-bands, then the base station can know the detailed information of each sub-band. However, in order to reduce the amount of channel quality feedback information, the feedback information is usually simplified, such as a Best-M scheme, which only indicates the M subbands with the best channel quality, such as M=4, then the feedback information only indicates the best channel quality 2/3/4/11 sub-bands; in order to further reduce the amount of feedback, it is possible to only feed back the average (8+11+9+8)/4=9 of the channel quality of these four sub-bands, instead of feeding back separately Four channel quality values.

In a frequency soft multiplexing system, generally, the user terminal only occupies the main frequency or only the sub-frequency, instead of occupying the main and sub-frequency at the same time. At this time, the simplified channel quality feedback method similar to Best-M needs to be optimized for the above characteristics. For example, in the above example, the UE feedbacks that the channel quality of the subbands numbered 2/3/4/11 is better. If the subbands numbered 0/1/2/3 are the main frequency and the other subbands are sub-frequency, Then for the user terminal occupying the main frequency, it is meaningless to feed back the subband numbered 4/11, otherwise the channel quality feedback information will occupy the amount of information; for the user terminal occupying the secondary frequency, feedback the subband numbered 2/3 The band is meaningless, otherwise the channel quality feedback information will occupy the amount of information.

In addition, due to the relatively large transmit power of the main frequency and the relatively small interference, the channel quality of the main frequency is better than that of the secondary frequency in some areas (especially inside the cell), so that the UE always selects the channel quality of the main frequency Feedback will also cause the system to work abnormally.

Therefore, in order to reduce the amount of channel quality feedback information in the technical solution described above, the simplified feedback information technology adopted may cause the simplified feedback information to contain some useless information or in some special cases the feedback is all useless information , and cause the system to malfunction.

Similar to the frequency soft multiplexing mentioned above, partial frequency multiplexing can also be used to improve spectrum utilization efficiency: a frequency multiplexing factor greater than 1 is used for the edge of the cell where the interference is relatively serious, and a frequency of 1 is used inside the cell multiplexing factor.

Specifically, as shown in FIG. 6 , an example in which the multiplexing factor of the primary frequency is 3 is used for illustration, and the subcarriers in the multi-carrier system are divided into two parts: the primary frequency and the secondary frequency. For the secondary frequency, its reuse factor is 1; the main frequency reuse factor is 3, that is, the main frequency part is divided into three sub-main frequency parts according to the cell: sub-main frequency 1, 2, 3, as shown in Figure 6 In the stripe part, each cell gets its own sub-primary frequency, and all cells use the same sub-frequency. The sub-primary frequency is mainly used for communication at the edge of the cell, and the sub-frequency is mainly used for communication inside the cell.

The problem of channel quality feedback in frequency soft multiplexing also exists in the partial frequency multiplexing shown in Figure 6, which may cause the simplified feedback information to contain some useless information or in some special cases the feedback is all useless information, which may cause the system to malfunction.

Contents of the invention

In view of this, the present invention provides a channel quality feedback method and its user terminal and system, which can make a network using interference coordination technologies such as frequency soft multiplexing work normally and efficiently.

A channel quality feedback method, including

Step A, dividing the entire frequency band into N subbands, where N is a positive integer greater than 1, and assigning each cell a main frequency subband and a subfrequency subband for cell communication;

Step B, determining that the user terminal uses at least one of the main frequency sub-band and the sub-frequency sub-band;

In step C, the user terminal respectively feeds back channel quality information to the transmitting end according to the subband information it uses.

A channel quality feedback system. The system mainly includes a base station and a user terminal. The base station further includes a subcarrier division module and a primary and secondary subband allocation module. The subcarrier division module divides the entire frequency band into N subbands, and N is a positive value greater than 1. Integer, the primary and secondary sub-band allocation module allocates the main frequency sub-band and secondary frequency sub-band for each cell according to the division result, then the base station and the user terminal communicate according to the above-mentioned sub-band division and allocation information, wherein, The base station also includes a sub-band usage determination module for determining that the user terminal uses at least one of the main frequency sub-band and the sub-frequency sub-band. The user terminal also includes a sub-band usage information generation module and a channel quality feedback module. The sub-band usage information generation module Generate corresponding subband usage information according to the subband usage information of the user terminal and transmit it to the channel quality feedback module, and the channel quality feedback module respectively feeds back channel quality information to the base station according to the subband usage information.

A user terminal for channel quality feedback, where the user terminal is used to communicate with a base station, wherein the user terminal includes a subband usage information generation module and a channel quality feedback module, and the subband usage information generation module is based on the subband used by the user terminal The corresponding sub-band usage information is generated and transmitted to the channel quality feedback module, and the channel quality feedback module respectively feeds back channel quality information according to the sub-band usage information.

Compared with the prior art, in the frequency soft multiplexing system of the present invention, the subband usage information generation module of the user terminal generates corresponding subband usage information according to the information of the subband used by the user terminal, and transmits the information to the user terminal channel quality feedback module, the channel quality feedback module can respectively feed back channel quality information according to the subband usage information, therefore, the channel quality feedback technology of the present invention can reduce the amount of information occupied by channel quality feedback information, and can always feed back some useful information, so that the system can work normally and efficiently.

Description of drawings

FIG. 1 is a schematic diagram of frequency reuse of a cellular network with a frequency reuse factor of 1 in the prior art.

FIG. 2 is a schematic diagram of frequency reuse of a cellular network with a reuse factor of 3 in the prior art.

FIG. 3 is a schematic diagram of frequency soft multiplexing of a cellular network with a frequency multiplexing factor of 3 in the prior art.

Fig. 4 is a schematic diagram of an OFDM system with 16 subcarriers in the prior art.

Fig. 5 is a schematic diagram of channel quality at a certain moment with 12 subbands in one of the prior art.

FIG. 6 is a schematic diagram of a partial frequency reuse cellular network frequency soft multiplexing in the prior art.

FIG. 7 is a block diagram of the working flow of channel quality feedback in a preferred embodiment of the present invention.

FIG. 8 is a schematic diagram of dividing subcarriers into subbands in a preferred embodiment of the present invention.

FIG. 9 is a schematic diagram of primary subcarrier allocation of each cell in a preferred embodiment of the present invention.

Fig. 10 is a structural block diagram of a channel quality feedback system in a preferred embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific implementation methods and accompanying drawings.

The channel quality feedback method and its user terminal and system of the present invention are not only applicable to systems using frequency soft multiplexing, but also applicable to systems using other frequency multiplexing interference coordination technologies such as partial frequency multiplexing.

In order to achieve multi-user terminal diversity gain and improve spectrum efficiency, the base station can select subcarriers with better conditions for different user terminals to transmit data based on certain scheduling criteria, so that the propagation conditions of most user terminals are relatively good , so in the frequency soft multiplexing system, the channel quality needs to be fed back to the sending end.

In a frequency soft multiplexing system, the channel quality characteristics of the main frequency and the secondary frequency are generally different, so their channel quality feedback needs to be processed separately. Therefore, a channel quality feedback method in a preferred embodiment of the present invention is shown in FIG. 7 , which mainly includes the following steps.

Step 101, dividing the entire frequency band into several sub-bands;

As shown in Figure 8, the system has a total of M subcarriers, and M is a positive integer greater than 1. All subcarriers in the system are divided into N groups, and N is a positive integer greater than 1. In this embodiment, M is a multiple of 4, that is, N =M/4, therefore, in this embodiment, it can also be expressed as dividing M subcarriers into subbands of M/4 groups.

The relationship of dividing subcarriers into subbands can be fixed or change dynamically according to time, that is, the grouping of subcarriers can be changed arbitrarily.

Step 102, the system allocates main frequency sub-bands and sub-frequency sub-bands for each cell according to certain rules;

Generally, the system allocates the main frequency sub-band and sub-frequency sub-band for each cell according to the rule that the main frequency occupies 1/3 of the frequency band and the secondary frequency occupies 2/3, but it can be adjusted in practice, such as according to business needs.

Through the base station controller, the system selects the above-mentioned different sub-carriers for different adjacent cells as the primary sub-carriers of the cell, and other sub-bands as secondary sub-carriers of the cell. The primary sub-carriers are mainly used for communication of user terminals at the edge of the cell. The carrier is mainly used for communication of user terminals inside the cell.

Different transmit power thresholds are set for the primary subcarrier and secondary subcarrier of each cell, and the transmit power threshold of the primary subcarrier is higher than that of the secondary subcarrier, and the cell boundary is determined by the coverage of the primary subcarrier. In this way, for the inside of the cell, low-power sub-carriers are mainly used to transmit user terminal data. Because it is relatively close to the base station, the terminal can receive clear signals in the cell, and because the power of the sub-carriers is small, the interference to adjacent cells is relatively small. , that is, the terminals inside the cell, due to the limitation of the transmission power of each base station, will not be interfered by the signal of the adjacent base station, or the interference is very small; while in the edge area of each adjacent cell, the high-power main subcarrier is used to transmit the user terminal data , the terminal in the edge area mainly receives the main subcarriers of the cell to which it belongs. Since the main subcarriers of different adjacent cells do not overlap and are not on the same frequency, they are orthogonal, so the mutual interference will be greatly reduced.

In addition, the division of subcarriers into subbands and the division of main subcarriers and sub-subcarriers can be fixed or dynamically changed according to time, that is, the grouping of subcarriers and the division of main subcarriers and sub-subcarriers can be changed freely, as long as It is sufficient that adjacent cells do not use the same subcarrier at the same time.

For example, as shown in Figure 9, there are 6 subcarriers, and the corresponding identifiers are 1, 2, 3, 4, 5, and 6 respectively. Within a time period, the subcarriers identified as 1 and 2 are divided into a group of subcarriers , the subcarriers marked as 3 and 5 are divided into a group of subcarriers, the subcarriers marked as 4 are divided into a group of subcarriers, the subcarriers marked as 6 are divided into a group of subcarriers, cell 1 is marked as The group of subcarriers of 1 and 2 is used as the main subcarrier of this cell, and the remaining subcarriers are used as subcarriers of this cell. The group of subcarriers marked as 4 is used as the main subcarrier of this cell in the adjacent cell 2, and the remaining subcarriers are used as subcarriers of this cell. The sub-subcarriers of this cell; after a period of time, these 5 subcarriers can be regrouped, the subcarriers marked 2 and 5 are divided into a group of subcarriers, and the subcarriers marked 4 and 6 are divided into a group of subcarriers Carrier, divide the subcarriers marked as 1 into a group of subcarriers, divide the subcarriers marked as 3 into a group of subcarriers, cell 1 uses the group of subcarriers marked as 4 and 6 as the main subcarriers of this cell, The remaining sub-carriers are used as sub-sub-carriers of this cell, the group of sub-carriers identified as 3 in the adjacent cell 2 is used as the main sub-carriers of this cell, and the remaining sub-carriers are used as sub-sub-carriers of this cell.

In partial frequency soft multiplexing, the subcarriers in the multi-carrier system are divided into two parts: primary frequency and secondary frequency. For the secondary frequency, its reuse factor is 1; the main frequency reuse factor is 3, that is, the main frequency part is divided into three sub-main frequency parts according to the cell: sub-main frequency 1, 2, 3, as shown in Figure 6 In the stripe part, each cell gets its own sub-primary frequency, and all cells use the same sub-frequency. The sub-primary frequency is mainly used for communication at the edge of the cell, and the sub-frequency is mainly used for communication inside the cell.

Step 103, determine whether the user terminal only uses the main frequency, only uses the sub-frequency or uses both the main and sub-frequency;

When the user terminal needs to transmit data, the user terminal feeds back the current CQI information to the base station, and the base station determines whether the user terminal uses only the main subcarrier, only the sub-subcarrier, or uses the main sub-subcarrier at the same time according to the current CQI information of the user terminal .

Generally, the base station determines the subcarriers used by the user terminal according to the amount of interference, that is, when the interference is large (which can be understood as poor CQI), the user terminal only uses the primary subcarrier; when the interference is small (which can be understood as good CQI), the user terminal The terminal only uses sub-subcarriers; however, in practical applications, the data requirements of the user terminal must also be considered. If the user terminal has a large amount of data, it may use the main sub-carrier and the sub-subcarrier at the same time.

Regarding whether the user terminal only uses the primary subcarrier, only the secondary subcarrier, or both the primary and secondary subcarriers, the base station can notify the user terminal through the broadcast channel, or notify the user terminal through other channels, or not notify the user terminal terminal.

Step 104, the user terminal respectively feeds back the channel quality to the transmitting end according to the sub-band usage information of whether it only uses the main frequency, only the sub-frequency or both the main and sub-frequency.

According to whether the user terminal only uses the main subcarrier, only uses the sub-subcarrier or uses the sub-band usage information of the main and sub-subcarrier at the same time, and according to whether the base station notifies the usage situation through the broadcast channel, the user terminal respectively feeds back the channel quality to the sending end, The details are as follows.

If the user terminal only uses the main subcarrier, and the base station has notified the user terminal through the broadcast channel, that is, the user terminal is aware of this usage, the user terminal only feeds back the channel quality of the main subcarrier to the sending end.

If the user terminal only uses the primary subcarrier, and the base station does not notify the user terminal through the broadcast channel, that is, the user terminal does not know this usage, the user terminal needs to feed back the channel quality of the primary subcarrier and secondary subcarrier of the cell to which it belongs to the sending end.

If the user terminal only uses the sub-subcarrier, and the base station has notified the user terminal through the broadcast channel, that is, the user terminal is aware of this usage, the user terminal only feeds back the channel quality of the sub-subcarrier to the sending end.

If the user terminal only uses sub-subcarriers, and the base station does not notify the user terminal through the broadcast channel, that is, the user terminal does not know this usage, the user terminal needs to feed back the channel quality of the primary sub-carrier and sub-subcarrier of the cell to which it belongs .

If the user terminal uses both the primary subcarrier and the secondary subcarrier, then regardless of whether the base station notifies the user terminal through the broadcast channel, that is, whether the user terminal knows this usage, the user terminal needs to feed back the primary subcarrier of the cell it belongs to to the sending end , The channel quality of sub-subcarriers.

The present invention also relates to a channel quality feedback system, as shown in FIG. 10 , which is a structural block diagram of a preferred channel quality feedback system in the present invention. The system mainly includes a base station and a user terminal, and the base station further includes a subcarrier division module, Main sub-band allocation module, transmit power setting module, sub-band usage information broadcasting module, sub-band usage determination module, sending module, user terminal further includes receiving module, sub-band usage information generation module, channel quality feedback module, wherein the base station also The subband usage information broadcast module may not be included.

The subcarrier division module divides all M subcarriers of the system into N groups of subbands, where N is a positive integer greater than 1, and M is a positive integer greater than 1. In this embodiment, M is a multiple of 4, that is, N=M/4 , the subcarrier division module sends the division result to the sending module.

The subcarrier division module divides M subcarriers into N groups of subbands, and the relationship of N=M/4 can be fixed or dynamically changed according to time, that is, the grouping of subcarriers can be changed arbitrarily.

The main sub-band allocation module allocates main frequency sub-bands and sub-frequency sub-bands to each cell according to certain rules according to the division result of the sub-carrier division module. The primary and secondary sub-band allocation module generally allocates the main frequency sub-band and secondary frequency sub-band for each cell according to the rule that the main frequency occupies 1/3 of the frequency band and the secondary frequency occupies 2/3, but it can be adjusted in practice, such as according to Business requirements are adjusted, and the primary and secondary sub-bands are allocated and the allocation result is transmitted to the sending module.

The primary and secondary sub-band allocation module can be the base station controller of the system. The primary and secondary sub-band allocation is to select the above-mentioned different sub-bands as the primary sub-carriers of this cell for different adjacent cells, and other sub-bands as secondary sub-carriers of this cell. The carrier is mainly used for communication of user terminals at the edge of the cell, and the sub-carrier is mainly used for communication of user terminals inside the cell.

The transmit power setting module sets different transmit power thresholds for the primary subcarrier and secondary subcarriers of each cell, and the transmit power threshold of the primary subcarrier is higher than the transmit power threshold of the secondary subcarriers. The coverage of the primary subcarrier determines the cell boundary. The transmit power The setting module transmits the setting result to the sending module.

In this way, for the inside of the cell, low-power sub-carriers are mainly used to transmit user terminal data. Because it is relatively close to the base station, the terminal can receive clear signals in the cell, and because the power of the sub-carriers is small, the interference to adjacent cells is relatively small. , that is, the terminals inside the cell, due to the limitation of the transmission power of each base station, will not be interfered by the signal of the adjacent base station, or the interference is very small; while in the edge area of each adjacent cell, the high-power main subcarrier is used to transmit the user terminal data , the terminal in the edge area mainly receives the main subcarriers of the cell to which it belongs. Since the main subcarriers of different adjacent cells do not overlap and are not on the same frequency, they are orthogonal, so the mutual interference will be greatly reduced. The transmission power setting module can also dynamically adjust the transmission power thresholds set by the main subcarrier and the secondary subcarrier.

In addition, the division of subcarriers into subbands and the division of main subcarriers and sub-subcarriers can be fixed or dynamically changed according to time, that is, the grouping of subcarriers and the division of main subcarriers and sub-subcarriers can be changed arbitrarily, as long as the It is sufficient that adjacent cells do not use the same subcarrier at the same time.

When the user terminal needs to transmit data, the user terminal feeds back the current CQI information to the base station, and the subband usage determination module determines whether the user terminal only uses the primary subcarrier, only the secondary subcarrier, or both, according to the current CQI information of the user terminal main sub-carrier.

In addition, the sub-band usage determination module can also further transmit the sub-band usage information of whether the user terminal only uses the main sub-carrier, only uses the sub-sub-carrier, or uses the main sub-sub-carrier at the same time to the sub-band usage information broadcasting module, and the sub-band usage The information broadcasting module generates corresponding information about the sub-band used by the user terminal and transmits it to the sending module; the sub-band usage determination module can also directly determine whether the user terminal only uses the main sub-carrier, only uses the sub-sub-carrier, or uses the main sub-sub-carrier at the same time The information is transmitted to the sending module, and finally the sending module notifies the user terminal of the subband information used by the user terminal through the broadcast channel, or notifies the user terminal through other channels, or does not notify the user terminal.

The sub-band usage information generating module of the user terminal generates corresponding sub-band usage information according to whether the user terminal only uses the main sub-carrier, only uses the sub-sub-carrier or uses the main and sub-sub-carriers at the same time, and transmits the corresponding sub-band usage information to the channel quality feedback module.

If the sending module of the base station has notified the user terminal through the broadcast channel whether the user terminal only uses the main subcarrier, only uses the secondary subcarrier, or uses the main subcarrier at the same time, then the receiving module of the corresponding user terminal receives the information and returns This information needs to be passed to the channel quality feedback module.

According to whether the user terminal only uses the main sub-carrier, only uses the sub-sub-carrier or uses the sub-band usage information of the main and sub-sub-carrier at the same time, and according to whether the usage situation broadcast by the sub-band usage information broadcast module is received, the channel quality feedback module sends to The sending end feeds back the channel quality, which is specifically described as follows.

If the user terminal only uses the main subcarrier, and the sending module of the base station has notified the user terminal through the broadcast channel, the subband usage information generation module of the user terminal generates the information that the user terminal only uses the main subcarrier and sends it to the channel quality feedback module and the receiving module The user terminal receiving the broadcast only uses the main subcarrier information and transmits it to the channel quality feedback module, and the channel quality feedback module only feeds back the channel quality of the main subcarrier to the sending end according to the two kinds of information.

If the user terminal only uses the main subcarrier, and the transmission module of the base station does not notify the user terminal through the broadcast channel, the subband usage information generation module of the user terminal generates the information that the user terminal only uses the main subcarrier and sends it to the channel quality feedback module, and the channel quality feedback The module feeds back the channel quality of the primary subcarrier and secondary subcarrier of the cell to which the user terminal belongs to the sending end respectively according to the information.

If the user terminal only uses sub-subcarriers, and the sending module of the base station has notified the user terminal through the broadcast channel, the sub-band usage information generating module of the user terminal generates information that the user terminal only uses sub-subcarriers and sends it to the channel quality feedback module, and The user terminal whose receiving module receives the broadcast only uses sub-subcarrier information and transmits it to the channel quality feedback module, and the channel quality feedback module only feeds back the channel quality of the sub-subcarrier to the sending end according to the two kinds of information.

If the user terminal only uses sub-subcarriers, and the sending module of the base station does not notify the user terminal through the broadcast channel, then the sub-band usage information generating module generates the information that the user terminal only uses sub-subcarriers and sends it to the channel quality feedback module, and the channel quality feedback module According to the information, the channel quality of the primary subcarrier and the secondary subcarrier of the cell to which the user terminal belongs is respectively fed back to the transmitting end.

If the user terminal uses both the main sub-carrier and the sub-sub-carrier, the sub-band usage information generation module generates the information that the user terminal uses the main sub-carrier and the sub-sub-carrier and sends it to the channel quality feedback module. The channel notifies the user terminal, and the channel quality feedback module needs to respectively feed back the channel quality of the primary subcarrier and the secondary subcarrier of the cell to which the user terminal belongs to the sending end.

To sum up, it can be seen from the above preferred implementation modes of the present invention that for a channel quality feedback method of the present invention and its user terminal and system, since the subband usage information generation module of the user terminal can use the subband The corresponding sub-band usage information is generated and transmitted to the channel quality feedback module, and the channel quality feedback module can respectively feed back channel quality information according to the sub-band usage information. Therefore, the channel quality feedback technology of the present invention can reduce the occupation of channel quality feedback information. The amount of information, and can always feed back some useful information, so that the system can work normally and efficiently.

However, the above is only a preferred embodiment of the present invention, and is not intended to limit the protection scope of the present invention. Any person familiar with the technical field should recognize that within the scope of the spirit and principles of the present invention, any Modifications, equivalent replacements, improvements, etc., should all be included within the protection scope of the present invention.

Claims (9)

1. a channel quality feedback method is characterized in that, comprises

Steps A, dividing whole frequency band is N subband, N is the positive integer greater than 1, and is each sub-district

Divide the dominant frequency subband and the secondary subband frequently that are used in cell communication;

Step B determines whether user terminal only uses dominant frequency subband, only use pair frequency subband or use major-minor subband frequently simultaneously;

Step C only uses dominant frequency subband, secondary one of subband frequently if determine user terminal, and user terminal do not know the information that it uses subband, then receives the dominant frequency subband of its affiliated subdistrict of user terminal feedback, the secondary channel quality information of subband frequently; Or

Only use dominant frequency subband, secondary one of subband frequently if determine user terminal, and the information that user terminal is used subband informing user terminal, then receive the channel quality information of its corresponding employed subband of user terminal feedback; Or

Use dominant frequency subband, secondary subband frequently simultaneously if determine user terminal, then receive the dominant frequency subband of its affiliated subdistrict of user terminal feedback, the secondary channel quality information of subband frequently.

2. a kind of channel quality feedback method as claimed in claim 1 is characterized in that, and: step B further comprises according to the current CQI information of user terminal and determines that user terminal uses dominant frequency subband, secondary subband frequently one of at least.

3. a kind of channel quality feedback method as claimed in claim 1, it is characterized in that: the dominant frequency subband is used for the communication of cell boundary users terminal, secondary subband frequently is used for the communication of sub-district internal user terminal, and the transmitting power thresholding of dominant frequency subband is greater than the transmitting power thresholding of pair frequency subband.

4. channel-quality feedback system, this system comprises the base station, this base station further comprises subcarrier division module, major-minor allocation of subbands module, it is N subband that subcarrier is divided the Module Division whole frequency band, N is the positive integer greater than 1, major-minor allocation of subbands module is according to dividing the result is used for cell communication for each cell allocation dominant frequency subband and secondary subband frequently, then a base station and a user terminal communicate according to above-mentioned sub-band division and assignment information, it is characterized in that, the base station comprises also whether be used for definite user terminal only uses the dominant frequency subband, only use secondary subband frequently or use the subband of major-minor frequency subband to use determination module simultaneously, user terminal comprises that also subband uses information-generation module and channel-quality feedback module, subband uses information-generation module to be used for using the information of subband to produce respective sub-bands according to this user terminal and uses information and pass to the channel-quality feedback module

The channel-quality feedback module is used for, and only uses dominant frequency subband, secondary one of subband frequently if determine user terminal, and user terminal do not receive the information that it uses subband, to the dominant frequency subband of its affiliated subdistrict of base station feedback, the secondary channel quality information of subband frequently; Or, only use dominant frequency subband, secondary one of subband frequently if determine user terminal, and user terminal received the information of using subband, to the channel quality information of its corresponding employed subband of base station feedback; Or, use dominant frequency subband, secondary subband frequently simultaneously if determine user terminal, to the dominant frequency subband of its affiliated subdistrict of base station feedback, the secondary channel quality information of subband frequently.

5. a kind of channel-quality feedback as claimed in claim 4 system is characterized in that the base station also comprises a sending module, and sending module uses the information informing user terminal by broadcast channel with subband.

6. a kind of channel-quality feedback system that states as claim 4 is characterized in that, subband uses determination module to determine that according to the current CQI information of user terminal user terminal uses dominant frequency subband, secondary subband frequently one of at least.

7. a kind of channel-quality feedback as claimed in claim 4 system, it is characterized in that: the dominant frequency subband is used for the communication of cell boundary users terminal, secondary subband frequently is used for the communication of sub-district internal user terminal, and the base station comprises that also a transmitting power is provided with module the transmitting power thresholding of the transmitting power thresholding of dominant frequency subband greater than pair frequency subband is set.

8. the user terminal of a channel-quality feedback, this user terminal is used for communicating with the base station, it is characterized in that, this user terminal comprises that subband uses information-generation module and channel-quality feedback module, and subband uses information-generation module to use the information of subband to produce respective sub-bands according to this user terminal and uses information and pass to the channel-quality feedback module;

The channel-quality feedback module is used for, if user terminal only uses dominant frequency subband, secondary one of subband frequently, and user terminal do not receive the information that it uses subband, to the dominant frequency subband of its affiliated subdistrict of base station feedback, the secondary channel quality information of subband frequently; Or if user terminal only uses dominant frequency subband, secondary one of subband frequently, and user terminal received the information of using subband, to the channel quality information of its corresponding employed subband of base station feedback; Or, if user terminal uses dominant frequency subband, secondary subband frequently simultaneously, to the dominant frequency subband of its affiliated subdistrict of base station feedback, the secondary channel quality information of subband frequently.

9. the user terminal of a kind of channel-quality feedback as claimed in claim 8, it is characterized in that: user terminal also comprises a receiver module, receiver module receives subband by broadcast channel and uses information and pass to the channel-quality feedback module.

Images