CN104348584A

CN104348584A - Method for realizing channel quality feedback and prediction by aiming at ABS (almost blank subframe) mechanism

Info

Publication number: CN104348584A
Application number: CN201310347159.6A
Authority: CN
Inventors: 王栋耀; 刘建国; 王钧; 王宇鹏
Original assignee: Alcatel Lucent Shanghai Bell Co Ltd
Current assignee: Nokia Shanghai Bell Co Ltd
Priority date: 2013-08-09
Filing date: 2013-08-09
Publication date: 2015-02-11
Anticipated expiration: 2033-08-09
Also published as: WO2015019174A3; CN104348584B; WO2015019174A2

Abstract

The invention relates to a method for realizing channel quality feedback and prediction by aiming at an ABS (almost blank subframe) mechanism in service base station in a heterogeneous wireless communication system. The heterogeneous wireless communication system comprises a service base station, user equipment and at least two micro base stations. The method comprises the following steps that the service base station sends a first instruction to the user equipment for indicating the user equipment to carry out limitation measurement of channel state information of two groups of sub frame sub sets; the service base station receives the limitation measurement result of the channel state information of the first group of sub frame sub sets from the user equipment, and predicts the channel quality of each sub frame according to the limitation measurement result, so the link adaptation, the channel sensing dispatching and the data packet transmission are carried out, and HARQ (hybrid automatic repeat request) feedback is received; the service base station judges whether the limitation measurement result of the channel state information of the second group of sub frame sub sets needs to be started or not according to the HARQ feedback. According to the method, the channel quality feedback aiming at the ABS mechanism and more accurate channel quality prediction can be realized, so the performance of the whole wireless communication system is improved.

Description

Method for realizing channel quality feedback and prediction aiming at ABS mechanism

Technical Field

The present invention relates to the field of wireless communication, and more particularly, to a method for implementing channel quality feedback and prediction for an ABS mechanism in a serving base station in a heterogeneous wireless communication system and a method for assisting in implementing channel quality feedback and prediction for an ABS mechanism in a user equipment in a heterogeneous wireless communication system.

Background

A Heterogeneous network (HetNet) can be deployed flexibly and inexpensively due to its unique properties, and can provide a uniform broadband experience to users anywhere in the network by using a combination of macro, micro, pico, and relay base stations. To improve the performance of such heterogeneous networks, enhanced techniques for extending coverage may be further introduced, thereby enabling more user terminals to directly benefit from low-power base stations, such as micro base stations, pico base stations, and relay base stations. However, in the presence of a macro base station with strong downlink signal strength, in order for a user terminal to obtain service from a low-power base station, the low-power base station needs to coordinate with the macro base station to implement interference coordination for a control channel and a data channel. Therefore, the LTE-a proposes the technique of eICIC/abs (explicit blanking subframe), which is used as an important interference coordination technical solution in the heterogeneous network.

Since there are ABS subframes and non-ABS subframes, the channel condition of the user equipment is different on different slots. Therefore, it is necessary to employ a suitable mechanism to support the measurement and reporting of the channel condition, which is also the focus of the present invention.

To solve the above-mentioned problems, methods based on two sets of measurement subframe patterns have been proposed in the prior art today and have been defined in LTE-a. Generally, two sets of measurement patterns are determined according to the ABS pattern of the main interference base station, wherein one set of measurement patterns is used for normal subframes, and the other set of measurement patterns is used for ABS subframes. Both sets of measurements can be reported by the user equipment to the respective base station periodically or aperiodically.

However, the above-described method still has a number of disadvantages. In fact, the method defined in LTE-a is only suitable for being able to work properly if the ABS patterns employed in the respective networks are all consistent. Since if different base stations employ different ABS patterns, only two sets of measurement patterns may not be sufficient. Unless both sets of measurement modes are dynamically configured throughout runtime, this will result in a significant RRC signaling overhead.

In practical applications, the elcic/ABS model will preferably be adapted to the environment, where the environment refers to user equipment distribution, traffic load, and geometry. Thus, as shown in fig. 1, different macro base stations will have different ABS patterns due to the different situations they have.

Clearly, in this case, it would be difficult to get accurate channel quality for all subframes. Furthermore, the mobility of the user equipment will also make this worse. Without accurate channel estimation, it would be difficult to perform link matching and channel aware scheduling, resulting in poor system performance.

Disclosure of Invention

In view of the foregoing background and the related technical problems, a first aspect of the present invention provides a method for implementing channel quality feedback and prediction for an ABS mechanism in a serving base station in a heterogeneous wireless communication system, wherein the heterogeneous wireless communication system includes the serving base station, a user equipment and at least two macro base stations, the method comprising:

B. the serving base station sends a first instruction to the user equipment to instruct the user equipment to perform restrictive measurement of channel state information of two subframe subsets;

C. the serving base station receiving restrictive measurements of channel state information for a first set of sub-frame subsets from the user equipment and predicting channel quality for each sub-frame based on the restrictive measurements for link adaptation, channel aware scheduling and data packet transmission and receiving HARQ feedback;

d: the service base station judges whether the restrictive measurement result of the channel state information of the second group of subframe subsets needs to be started or not according to the HARQ feedback:

-if not, the method ends;

-if necessary, the serving base station sending a second instruction to the user equipment instructing the user equipment to report to the serving base station a restrictive measurement of the channel state information of the second subset of subframes, the serving base station optimizing the prediction of the channel quality of each subframe in step C according to the restrictive measurement of the channel state information of the second subset of subframes and the method returning to step C.

The method of the invention can realize the channel quality feedback aiming at the ABS mechanism and more accurate channel quality prediction, thereby providing powerful guarantee for more effectively realizing the reasonable utilization of wireless channel resources, improving the efficiency and improving the performance of the whole wireless communication system.

In one embodiment consistent with the present invention, the first set of sub-frame subsets is different from the second set of sub-frame subsets.

In one embodiment consistent with the present invention, the first set of sub-frame subsets is complementary to the second set of sub-frame subsets.

In an embodiment according to the present invention, before the step B, the method further includes:

A. the serving base station initializes a weight for prediction of channel quality of each subframe.

In one embodiment according to the present invention, the weights are updated in said step D according to a restrictive measure of the channel state information of a second subset of subframes to enable a prediction that optimizes the channel quality of said each subframe.

In one embodiment according to the present invention, the serving base station periodically receives a restrictive measurement result of the channel state information of the first set of sub-frame subsets from the user equipment.

In one embodiment according to the present invention, the serving base station transmits the second instruction to the user equipment in PDCCH or extended PDCCH signaling.

Furthermore, a second aspect of the present invention provides a method for assisting in implementing channel quality feedback and prediction for ABS mechanism in a user equipment in a heterogeneous wireless communication system, wherein the heterogeneous wireless communication system includes the serving base station, the user equipment and at least two macro base stations, the method comprising:

the user equipment receives a first instruction from the serving base station, wherein the first instruction instructs the user equipment to perform restrictive measurement on channel state information of two subframe subsets and send restrictive measurement results of the channel state information of the first subframe subset to the serving base station;

p. the user equipment receiving a second instruction from the serving base station instructing the user equipment to send a restrictive measurement result of channel state information of a second set of sub-frame subsets to the serving base station.

In one embodiment according to the present invention, the user equipment sends the restricted measurement result of the channel state information of the second set of sub-frame subsets to the serving base station together with HARQ feedback.

The method according to the first and second aspects of the present invention can realize the channel quality feedback for the ABS mechanism and more accurate channel quality prediction, thereby providing a strong guarantee for more effectively realizing the reasonable utilization of the wireless channel resources, improving the efficiency and improving the performance of the whole wireless communication system.

Drawings

Other features, objects and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments thereof, which proceeds with reference to the accompanying drawings.

FIG. 1 shows a schematic diagram of an ABS implementation according to the prior art; and

fig. 2 shows an application scenario to which the method according to the invention is applied; and

fig. 3 shows a flow chart 300 of an embodiment of a method according to the invention.

In the drawings, like or similar reference numbers indicate like or similar devices (modules) or steps throughout the different views.

Detailed Description

In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof. The accompanying drawings illustrate, by way of example, specific embodiments in which the invention may be practiced. The illustrated embodiments are not intended to be exhaustive of all embodiments according to the invention. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

Therefore, aiming at the scene of configuring eICIC/ABS in the heterogeneous network, the invention provides a novel method for channel quality feedback and prediction. The main concept includes the following aspects:

first, the serving base station will configure a set of restricted measurement subsets for the user equipment. According to the restrictive measurement configuration, the user equipment performs restrictive Channel State Information (CSI) measurement and reports it to the serving base station. Typically, such reporting will be done periodically. Based on this CSI information, the base station is able to predict the channel quality over all subframes and perform corresponding link adaptation and channel aware scheduling.

During the data transmission, the base station will monitor the performance of the HARQ transmission and, if its failure rate is greater than a certain threshold, will trigger the user equipment to perform measurements on a second set of restricted measurement subsets, which can also be preconfigured.

Wherein the trigger can be configured by PDCCH signaling, and the trigger can also be extended to inform the user equipment whether the channel quality measured on the second restrictive subframe pattern can be sent back with HARQ feedback.

By means of the obtained channel quality report sent back together with the HARQ feedback, the base station is able to optimize the prediction of the channel quality, thus obtaining more accurate channel information, and then is able to better optimize link adaptation and channel aware scheduling.

Fig. 1 shows a schematic diagram of an ABS implementation according to the prior art. This figure has already been described in the background section and is not described again here for the sake of brevity.

Fig. 2 shows an application scenario to which the method according to the invention is applied. As can be seen from the figure, the illustrated user equipment UE is affected by a plurality of macro base stations while communicating with the serving base station, because the illustrated user equipment UE is simultaneously within the coverage of two macro base stations, in order to effectively solve the effect of the macro base stations and reduce the effect, thereby optimizing the performance of the wireless communication system, the present invention provides methods implemented in the serving base station and the user equipment, so as to cooperate with each other and optimize the wireless resources.

The concepts and specific implementations of the invention are described in greater detail below.

First, the inventors of the present invention made the following assumptions:

for each user equipment, its corresponding dominant interfering node is determined and a weight is assigned to each interfering node. Physically, the weight represents the relationship between its serving node and interfering node for a certain user equipment, as it is shown in fig. 2 and the following equation:

first, the base station will determine for each user equipment the dominant interference source of the interference it receives. Assuming that there are a total of N dominant interfering nodes for user equipment k, the interference source vector is:

MInt(k)＝{I₁，I₂，…，I_N} (1)

also, a weight vector is defined for the dominant interfering nodes:

W(k)＝{w₁，w₂，…，w_N} (2)

the weight vector is applied to the following equation:

where S denotes the useful signal received from the service node, I_iRepresenting the received power, RSRP, from the i-th interfering node₀RSRP representing a serving node reported from a user equipment, and RSRP_iIndicating the RSRP of the ith interfering node reported by the user equipment. All weights should be greater than zero and initialized to 1.0. This information is generated when the user equipment is switched on and is updated during the handover. In the processes, the base station can obtain corresponding RSRP of the user equipment_i(i ═ 0, 1, 2.., N) information.

The base station will then acquire information of the ABS pattern of the neighbouring base stations when needed over the X2 interface, which has been defined in LTE-a.

Next, the base station will determine two sets of measurement subframe patterns for each user equipment.

In particular, on the first measurement subframe pattern, the dominant interfering node has the configuration of [ a₁，A₂，…，A_N]Wherein A is_i(i ═ 1, 2, …, N) ∈ {0, 1}, anda 1 indicates an ABS subframe and a 0 indicates a normal (i.e., non-ABS) subframe.

On the second measurement subframe pattern, the dominant interfering node has the following configuration, namely B₁，B₂，…，B_N]Wherein B is_i(i ═ 1, 2, …, N) ∈ {0, 1}, with 1 indicating an ABS subframe and 0 indicating a normal (i.e., non-ABS) subframe.

Preferably, the two sets of measurement subframe patterns are complementary from the perspective of the dominant interfering node, e.g.:

[A₁，A₂，A₃，A₄]＝[0，1，0，1]and [ B ] is₁，B₂，B₃，B₄]＝[1，0，1，0]。

Assuming that the measured CSI for the first set of measurement subframe patterns is SINR_MeasIt will be reported to the base station periodically or aperiodically according to the reporting configuration.

When the base station allocates (schedules) resources for the target subframe n, the base station will determine the state of the dominant interference to the user equipment k based on the obtained ABS pattern, which can be expressed as:

[Y₁，Y₂，…，Y_N]wherein Y is_i(i ═ 1, 2, …, N) ∈ {0, 1}, with 1 indicating an ABS subframe and 0 indicating a normal (i.e., non-ABS) subframe.

And the base station will predict the channel conditions based on the following formula:

<math> <mrow> <mi>SIN</mi> <msub> <mi>R</mi> <mi>pre</mi> </msub> <mrow> <mo>(</mo> <mi>dB</mi> <mo>)</mo> </mrow> <mo>=</mo> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Meas</mi> </msub> <mrow> <mo>(</mo> <mi>dB</mi> <mo>)</mo> </mrow> <mo>-</mo> <mn>10</mn> <mo>×</mo> <mi>log</mi> <mn>10</mn> <mrow> <mo>(</mo> <mn>1</mn> <mo>+</mo> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Meas</mi> </msub> <mrow> <mo>(</mo> <mi>Linear</mi> <mo>)</mo> </mrow> <mo>×</mo> <munderover> <mi>Σ</mi> <mrow> <mi>i</mi> <mo>=</mo> <mn>1</mn> </mrow> <mi>N</mi> </munderover> <mrow> <mo>(</mo> <msub> <mi>w</mi> <mi>i</mi> </msub> <mo>×</mo> <mfrac> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mi>i</mi> </msub> </mrow> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mn>0</mn> </msub> </mrow> </mfrac> <mo>×</mo> <mrow> <mo>(</mo> <msub> <mi>A</mi> <mi>i</mi> </msub> <mo>-</mo> <msub> <mi>Y</mi> <mi>i</mi> </msub> <mo>)</mo> </mrow> <mo>)</mo> </mrow> <mo>)</mo> </mrow> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>4</mn> <mo>)</mo> </mrow> </mrow> </math>

with this prediction, the base station can perform channel-aware scheduling and determine the MCS for the corresponding transmission.

Next, during the transmission, the base station will monitor the performance of the HARQ transmission, and if the failure rate of the HARQ transmission exceeds a certain threshold, the base station will trigger the user equipment to perform the restrictive measurement on the second restrictive measurement subset. The trigger can be configured on the extended PDCCH, which is used to inform the user equipment whether HARQ feedback should be sent back together with the channel quality measured on the corresponding restricted subframe pattern.

If the above indication is set, the user equipment originated HARQ feedback message will be sent back together with the CSI information measured on the second restricted subframe set.

If the CSI for the second set of measurement subframe patterns is received, then the weight of the dominant interfering node will be updated as follows:

A) assuming that the reported CSI is SINR_Channel。

B)

Wherein,

<math> <mrow> <msub> <mi>μ</mi> <mi>i</mi> </msub> <mo>=</mo> <mfrac> <mrow> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Meas</mi> </msub> <mrow> <mo>(</mo> <mi>Linear</mi> <mo>)</mo> </mrow> <mo>×</mo> <mfrac> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mi>i</mi> </msub> </mrow> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mn>0</mn> </msub> </mrow> </mfrac> <mo>×</mo> <mrow> <mo>(</mo> <msub> <mi>A</mi> <mi>i</mi> </msub> <mo>-</mo> <msub> <mi>B</mi> <mi>i</mi> </msub> <mo>)</mo> </mrow> </mrow> <mrow> <mn>1</mn> <mo>+</mo> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Meas</mi> </msub> <mrow> <mo>(</mo> <mi>Linear</mi> <mo>)</mo> </mrow> <mo>×</mo> <munderover> <mi>Σ</mi> <mrow> <mi>i</mi> <mo>=</mo> <mn>1</mn> </mrow> <mi>N</mi> </munderover> <mrow> <mo>(</mo> <msub> <mi>w</mi> <mi>i</mi> </msub> <mo>×</mo> <mfrac> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mi>i</mi> </msub> </mrow> <mrow> <mi>RSR</mi> <msub> <mi>R</mi> <mn>0</mn> </msub> </mrow> </mfrac> <mo>×</mo> <mrow> <mo>(</mo> <msub> <mi>A</mi> <mi>i</mi> </msub> <mo>-</mo> <msub> <mi>B</mi> <mi>i</mi> </msub> <mo>)</mo> </mrow> <mo>)</mo> </mrow> </mrow> </mfrac> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>6</mn> <mo>)</mo> </mrow> </mrow> </math>

<math> <mrow> <mi>Ψ</mi> <mo>=</mo> <mrow> <mo>(</mo> <mrow> <mo>(</mo> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Channel</mi> </msub> <mrow> <mo>(</mo> <mi>dB</mi> <mo>)</mo> </mrow> <mo>-</mo> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Pre</mi> </msub> <mrow> <mo>(</mo> <mi>dB</mi> <mo>)</mo> </mrow> <mo>)</mo> </mrow> <mo>×</mo> <mfrac> <mn>10</mn> <mrow> <mi>log</mi> <mrow> <mo>(</mo> <mn>10</mn> <mo>)</mo> </mrow> </mrow> </mfrac> <mo>)</mo> </mrow> <mo>·</mo> <mi>Δ</mi> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>7</mn> <mo>)</mo> </mrow> </mrow> </math>

Δ is the step size.

C) Convergence of the weight vector W can be obtained by a loop of

While(|SINR_Channel(dB)-SINR_Pre(dB)|＞)

Update according to equation (5)

End

Additionally, if a new RSRP is reported_iThen the corresponding weight w will be updated according to the following equation_i：

If the RSRP of one of the user equipments is reported₀Then all the weights associated with that user equipment will be updated with the following formula:

if RSRP_iAnd RSRP₀While reporting, then the corresponding weight will be reset to 1.0.

Finally, as described in the above steps, the base station will then make predictions of the channel quality for all subframes with the newly updated weights, and then perform link adaptation and channel aware scheduling, etc.

The complete deduction of the above formula is described as follows:

first, assume that the interference power (plus noise) of the first set of measurement subframe patterns is I_MeasAnd the interference power (plus noise) of the second set of measured subframe patterns is I_PreAnd then:

thus, the desired channel quality is:

if expressed in dB, is:

while

I_{Meas} = \frac{S}{SIN R_{Meas} (Linear)} - - - (13)

Therefore, combining equations (2), (12), and (13) can obtain:

<math> <mrow> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Pre</mi> </msub> <mrow> <mo>(</mo> <mi>dB</mi> <mo>)</mo> </mrow> <mo>=</mo> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Meas</mi> </msub> <mrow> <mo>(</mo> <mi>dB</mi> <mo>)</mo> </mrow> <mo>-</mo> <mn>10</mn> <mo>×</mo> <mi>log</mi> <mn>10</mn> <mrow> <mo>(</mo> <mn>1</mn> <mo>+</mo> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Meas</mi> </msub> <mrow> <mo>(</mo> <mi>Linear</mi> <mo>)</mo> </mrow> <mo>×</mo> <munderover> <mi>Σ</mi> <mrow> <mi>i</mi> <mo>=</mo> <mn>1</mn> </mrow> <mi>N</mi> </munderover> <mrow> <mo>(</mo> <msub> <mi>w</mi> <mi>i</mi> </msub> <mo>×</mo> <mfrac> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mi>i</mi> </msub> </mrow> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mn>0</mn> </msub> </mrow> </mfrac> <mo>×</mo> <mrow> <mo>(</mo> <msub> <mi>A</mi> <mi>i</mi> </msub> <mo>-</mo> <msub> <mi>B</mi> <mi>i</mi> </msub> <mo>)</mo> </mrow> <mo>)</mo> </mrow> <mo>)</mo> </mrow> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>14</mn> <mo>)</mo> </mrow> </mrow> </math>

defining a normalization function:

<math> <mrow> <mi>F</mi> <mrow> <mo>(</mo> <msub> <mi>w</mi> <mn>0</mn> </msub> <mo>,</mo> <msub> <mi>w</mi> <mn>1</mn> </msub> <mo>,</mo> <mo>·</mo> <mo>·</mo> <mo>·</mo> <mo>,</mo> <msub> <mi>w</mi> <mi>N</mi> </msub> <mo>)</mo> </mrow> <mo>=</mo> <munder> <mi>min</mi> <mrow> <mi>w</mi> <mo>&Element;</mo> <mi>W</mi> </mrow> </munder> <msup> <mrow> <mo>(</mo> <msub> <mi>SINR</mi> <mi>channel</mi> </msub> <mrow> <mo>(</mo> <mi>dB</mi> <mo>)</mo> </mrow> <mo>-</mo> <msub> <mi>SINR</mi> <mi>Pre</mi> </msub> <mrow> <mo>(</mo> <mi>dB</mi> <mo>)</mo> </mrow> <mo>)</mo> </mrow> <mn>2</mn> </msup> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>15</mn> <mo>)</mo> </mrow> </mrow> </math>

under the following conditions:

1、w_i＞0 (16)

2、

<math> <mrow> <msub> <mi>SINR</mi> <mi>Meas</mi> </msub> <mrow> <mo>(</mo> <mi>Linear</mi> <mo>)</mo> </mrow> <mo>×</mo> <munderover> <mi>Σ</mi> <mrow> <mi>i</mi> <mo>=</mo> <mn>1</mn> </mrow> <mi>N</mi> </munderover> <mrow> <mo>(</mo> <msub> <mi>w</mi> <mi>i</mi> </msub> <mo>×</mo> <mfrac> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mi>i</mi> </msub> </mrow> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mn>0</mn> </msub> </mrow> </mfrac> <mo>×</mo> <mrow> <mo>(</mo> <msub> <mi>A</mi> <mi>i</mi> </msub> <mo>-</mo> <msub> <mi>B</mi> <mi>i</mi> </msub> <mo>)</mo> </mrow> <mo>)</mo> </mrow> <mo>></mo> <mn>0</mn> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>17</mn> <mo>)</mo> </mrow> </mrow> </math>

therefore, the method comprises the following steps:

<math> <mrow> <mfrac> <mrow> <mo>&PartialD;</mo> <mi>F</mi> </mrow> <mrow> <mo>&PartialD;</mo> <msub> <mi>w</mi> <mi>i</mi> </msub> </mrow> </mfrac> <mo>=</mo> <mrow> <mo>(</mo> <mi>SIN</mi> <msub> <mi>R</mi> <mi>channel</mi> </msub> <mrow> <mo>(</mo> <mi>dB</mi> <mo>)</mo> </mrow> <mo>-</mo> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Pre</mi> </msub> <mrow> <mo>(</mo> <mi>dB</mi> <mo>)</mo> </mrow> <mo>)</mo> </mrow> <mo>×</mo> <mfrac> <mn>10</mn> <mrow> <mi>log</mi> <mrow> <mo>(</mo> <mn>10</mn> <mo>)</mo> </mrow> </mrow> </mfrac> <mo>×</mo> </mrow> </math>

<math> <mrow> <mfrac> <mrow> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Meas</mi> </msub> <mrow> <mo>(</mo> <mi>Linear</mi> <mo>)</mo> </mrow> <mo>×</mo> <mfrac> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mi>i</mi> </msub> </mrow> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mn>0</mn> </msub> </mrow> </mfrac> <mo>×</mo> <mrow> <mo>(</mo> <msub> <mi>A</mi> <mi>i</mi> </msub> <mo>-</mo> <msub> <mi>B</mi> <mi>i</mi> </msub> <mo>)</mo> </mrow> </mrow> <mrow> <mn>1</mn> <mo>+</mo> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Meas</mi> </msub> <mrow> <mo>(</mo> <mi>Linear</mi> <mo>)</mo> </mrow> <mo>×</mo> <munderover> <mi>Σ</mi> <mrow> <mi>i</mi> <mo>=</mo> <mn>1</mn> </mrow> <mi>N</mi> </munderover> <mrow> <mo>(</mo> <msub> <mi>w</mi> <mi>i</mi> </msub> <mo>×</mo> <mfrac> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mi>i</mi> </msub> </mrow> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mn>0</mn> </msub> </mrow> </mfrac> <mo>×</mo> <mrow> <mo>(</mo> <msub> <mi>A</mi> <mi>i</mi> </msub> <mo>-</mo> <msub> <mi>B</mi> <mi>i</mi> </msub> <mo>)</mo> </mrow> <mo>)</mo> </mrow> </mrow> </mfrac> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>18</mn> <mo>)</mo> </mrow> </mrow> </math>

wherein, RSRP is a linear value, and according to a gradient algorithm, the RSRP is as follows:

<math> <mrow> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>w</mi> <mn>1</mn> </msub> </mtd> </mtr> <mtr> <mtd> <msub> <mi>w</mi> <mn>2</mn> </msub> </mtd> </mtr> <mtr> <mtd> <mo>.</mo> </mtd> </mtr> <mtr> <mtd> <mo>.</mo> </mtd> </mtr> <mtr> <mtd> <mo>.</mo> </mtd> </mtr> <mtr> <mtd> <msub> <mi>w</mi> <mi>n</mi> </msub> </mtd> </mtr> </mtable> </mfenced> <mrow> <mo>(</mo> <mi>new</mi> <mo>)</mo> </mrow> <mo>=</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <msub> <mi>w</mi> <mn>1</mn> </msub> </mtd> </mtr> <mtr> <mtd> <msub> <mi>w</mi> <mn>2</mn> </msub> </mtd> </mtr> <mtr> <mtd> <mo>.</mo> </mtd> </mtr> <mtr> <mtd> <mo>.</mo> </mtd> </mtr> <mtr> <mtd> <mo>.</mo> </mtd> </mtr> <mtr> <mtd> <msub> <mi>w</mi> <mi>N</mi> </msub> </mtd> </mtr> </mtable> </mfenced> <mrow> <mo>(</mo> <mi>old</mi> <mo>)</mo> </mrow> <mo>-</mo> <mfenced open='[' close=']'> <mtable> <mtr> <mtd> <mfrac> <mrow> <mo>&PartialD;</mo> <mi>F</mi> </mrow> <mrow> <mo>&PartialD;</mo> <msub> <mi>w</mi> <mn>1</mn> </msub> </mrow> </mfrac> </mtd> </mtr> <mtr> <mtd> <mfrac> <mrow> <mo>&PartialD;</mo> <mi>F</mi> </mrow> <mrow> <mo>&PartialD;</mo> <msub> <mi>w</mi> <mn>2</mn> </msub> </mrow> </mfrac> </mtd> </mtr> <mtr> <mtd> <mo>.</mo> </mtd> </mtr> <mtr> <mtd> <mo>.</mo> </mtd> </mtr> <mtr> <mtd> <mo>.</mo> </mtd> </mtr> <mtr> <mtd> <mfrac> <mrow> <mo>&PartialD;</mo> <mi>F</mi> </mrow> <mrow> <mo>&PartialD;</mo> <msub> <mi>w</mi> <mi>N</mi> </msub> </mrow> </mfrac> </mtd> </mtr> </mtable> </mfenced> <mo>·</mo> <mi>Δ</mi> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>19</mn> <mo>)</mo> </mrow> </mrow> </math>

wherein,

<math> <mrow> <msub> <mi>μ</mi> <mi>i</mi> </msub> <mo>=</mo> <mfrac> <mrow> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Meas</mi> </msub> <mrow> <mo>(</mo> <mi>Linear</mi> <mo>)</mo> </mrow> <mo>×</mo> <mfrac> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mi>i</mi> </msub> </mrow> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mn>0</mn> </msub> </mrow> </mfrac> <mo>×</mo> <mrow> <mo>(</mo> <msub> <mi>A</mi> <mi>i</mi> </msub> <mo>-</mo> <msub> <mi>B</mi> <mi>i</mi> </msub> <mo>)</mo> </mrow> </mrow> <mrow> <mn>1</mn> <mo>+</mo> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Meas</mi> </msub> <mrow> <mo>(</mo> <mi>Linear</mi> <mo>)</mo> </mrow> <mo>×</mo> <munderover> <mi>Σ</mi> <mrow> <mi>i</mi> <mo>=</mo> <mn>1</mn> </mrow> <mi>N</mi> </munderover> <mrow> <mo>(</mo> <msub> <mi>w</mi> <mi>i</mi> </msub> <mo>×</mo> <mfrac> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mi>i</mi> </msub> </mrow> <mrow> <mi>RSR</mi> <msub> <mi>P</mi> <mn>0</mn> </msub> </mrow> </mfrac> <mo>×</mo> <mrow> <mo>(</mo> <msub> <mi>A</mi> <mi>i</mi> </msub> <mo>-</mo> <msub> <mi>B</mi> <mi>i</mi> </msub> <mo>)</mo> </mrow> <mo>)</mo> </mrow> </mrow> </mfrac> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>20</mn> <mo>)</mo> </mrow> </mrow> </math>

<math> <mrow> <mi>Ψ</mi> <mo>=</mo> <mrow> <mo>(</mo> <mrow> <mo>(</mo> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Channel</mi> </msub> <mrow> <mo>(</mo> <mi>dB</mi> <mo>)</mo> </mrow> <mo>-</mo> <mi>SIN</mi> <msub> <mi>R</mi> <mi>Pre</mi> </msub> <mrow> <mo>(</mo> <mi>dB</mi> <mo>)</mo> </mrow> <mo>)</mo> </mrow> <mo>×</mo> <mfrac> <mn>10</mn> <mrow> <mi>log</mi> <mrow> <mo>(</mo> <mn>10</mn> <mo>)</mo> </mrow> </mrow> </mfrac> <mo>)</mo> </mrow> <mo>·</mo> <mi>Δ</mi> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>21</mn> <mo>)</mo> </mrow> </mrow> </math>

here, Δ will be dynamically determined so as to satisfy the above-mentioned two constraints, i.e., equations (16) and (17).

A specific embodiment of the solution proposed by the present invention will be given below, as shown in fig. 3. As can be seen from the figure, a method for implementing channel quality feedback and prediction for an ABS mechanism in a heterogeneous wireless communication system, where the heterogeneous wireless communication system includes a serving base station, a user equipment and at least two macro base stations, and a specific scenario is shown in fig. 2, the method includes:

in step 320, the serving base station sends a first instruction to the ue to instruct the ue to perform a restrictive measurement on the channel state information of the two sets of subframe subsets; before this, initialization of the weights can also be performed in step 310;

next, in step 330, the serving base station receives restrictive measurements of channel state information of the first set of sub-frame subsets from the user equipment and predicts channel quality of each sub-frame according to the restrictive measurements in step 340, thereby performing link adaptation, channel aware scheduling and data packet transmission and receiving HARQ feedback;

in step 350, the serving base station determines whether to enable the restrictive measurement result of the channel state information of the second set of subframe subsets according to the HARQ feedback:

-if not, the method ends;

-if necessary, the serving base station sending in method step 360 a second instruction to the user equipment instructing the user equipment to measure the channel in step 370 and to report in step 380 the restrictive measurement of the channel state information of the second set of sub-frame subsets to the serving base station, finally, in step 390 the serving base station optimizing the weights according to the restrictive measurement of the channel state information of the second set of sub-frame subsets and continuing the method, repeating the above steps 350 to 390 as long as the serving base station judges that it is deemed necessary to enable the restrictive measurement of the channel state information of the second set of sub-frame subsets, and so on until the process ends.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. Furthermore, it will be obvious that the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. Several elements recited in the apparatus claims may also be implemented by one element. The terms first, second, etc. are used to denote names, but not any particular order.

Claims

1. A method of enabling channel quality feedback and prediction for ABS mechanisms in a serving base station in a heterogeneous wireless communication system, wherein the heterogeneous wireless communication system comprises the serving base station, a user equipment and at least two macro base stations, the method comprising:

-if not, the method ends;

2. The method of claim 1, wherein the first set of sub-frame subsets is different from the second set of sub-frame subsets.

3. The method of claim 1, wherein the first set of sub-frame subsets is complementary to the second set of sub-frame subsets.

4. The method of claim 1, wherein prior to step B, further comprising:

5. The method according to claim 4, wherein the weights are to be updated in said step D based on restrictive measurements of channel state information for a second subset of subframes to enable a prediction that optimizes the channel quality for said each subframe.

6. The method of claim 1, wherein the serving base station periodically receives a restrictive measurement of channel state information for the first set of subsets of subframes from the user equipment.

7. The method of claim 1, wherein the serving base station transmits the second instruction to the user equipment in PDCCH or extended PDCCH signaling.

8. A method of assisting in enabling channel quality feedback and prediction for ABS mechanisms in a user equipment in a heterogeneous wireless communication system, wherein the heterogeneous wireless communication system comprises the serving base station, the user equipment and at least two macro base stations, the method comprising:

9. The method of claim 8, wherein the first set of sub-frame subsets is complementary to the second set of sub-frame subsets.

10. The method of claim 8, wherein the user equipment sends restrictive measurements of channel state information for the second subset of subframes to the serving base station along with HARQ feedback.