WO2015149709A1 - Noise power estimation method and network side device - Google Patents

Abstract

The present invention relates to the technical field of wireless communications, particularly to a noise power estimation method and a network side device, to solve the problem in the prior art of a high noise power value obtained from noise power estimation. When selecting interfering noise windows, an embodiment of the present application uses all time-domain signal paths, other than user signal windows in a target cell, as interfering noise windows to improve accuracy of interfering noise value estimation, and directly uses the interfering noise value as a threshold value to determine effective time-domain signal paths during channel estimation, avoiding missing some actual time-domain signal paths when selecting effective time-domain signal paths, thus improving accuracy of channel estimation.

Description

Noise power estimation method and network side device

This application claims the priority of the Chinese Patent Application filed on April 4, 2014, the Chinese Patent Office, the application number is "201410136876.9", and the invention is entitled "A Noise Power Estimation Method and Network Side Device", the entire contents of which are incorporated by reference. Combined in this application.

Technical field

The present invention relates to the field of wireless communication technologies, and in particular, to a noise power estimation method and a network side device.

Background technique

Channel estimation and noise power estimation algorithms have a critical impact on the throughput performance of wireless mobile communication systems. The channel estimation algorithm can use Least Squares (LS), Inverse Discrete Fourier Transform (IDFT) transform domain method and Minimum Mean Square Error (MMSE) linear estimation. algorithm. A typical channel estimation algorithm for Long Term Evolution (LTE) uplink system is a channel estimation algorithm based on IDFT transform. The advantage is that channel estimation and noise power estimation can be performed simultaneously.

In a specific co-frequency networking scenario, the base sequence group numbers of different cells managed by the same evolved base station (eNB) are the same, and different cells of the same base station are differentiated by different cyclic time shifts. In the scenario of the uplink virtual multi-user multiple input multiple output (MU-MIMO) condition, the channel estimation method is as shown in FIG. 1 and includes the following steps:

Step 101: Perform frequency domain LS channel estimation on the pilot symbols to obtain an initial frequency domain channel estimation value.

Step 102: Perform IDFT transform on the initial frequency domain channel estimation value to obtain a time domain channel estimation sequence before processing.

Step 103: Perform windowing and noise suppression operation on the time domain channel estimation sequence to obtain a noise suppression time domain channel estimation sequence h' _P .

Step 104: Perform a DFT (Discrete Fourier Transform) transform on the noise-suppressed time domain channel estimation sequence to obtain a frequency domain channel estimation value H′ _{P of the} pilot symbol.

Step 105: Perform time domain linear interpolation on the frequency domain channel estimation value of the pilot symbol to obtain a frequency domain channel estimation value H' _{Data of the} data symbol.

Wherein, step 103 specifically includes:

In step 1031, noise power estimation is performed. Selecting a user signal window and an interference noise window, and then performing noise power estimation according to a time domain signal path in the interference noise window to obtain a noise power value;

Step 1032, determining the threshold TH of the effective time domain signal path according to the strongest time domain signal path and the noise power value in the user signal window;

Step 1033: Filter the time domain signal path that needs to be reserved in the user signal window according to the threshold value, and the time domain that does not need to be reserved The signal path is set to zero;

Step 1034: Zero the time domain signal path in the noise window to obtain a time-domain channel estimation sequence h' _{P of the} noise suppression.

In the above method, the user signal window and the interference noise window selected in step 1031 are as shown in FIG. 2. In the above-mentioned specific co-frequency networking scenario, the interference and noise are distributed differently in all time-domain windows including the user signal window and the interference noise window, which may cause the noise power value obtained by the noise power estimation to be too large. . If the channel estimation is performed with a large noise power value, the threshold value when the effective time domain signal path is selected is too large, and some real time domain signal paths are missed when the effective time domain signal path is selected, which affects the channel. Estimated accuracy.

Summary of the invention

The present invention provides a noise power estimation method and a network side device, which are used to solve the problem that the noise power value obtained by estimating the noise power in the prior art is excessive.

An embodiment of the present invention provides a noise power estimation method, where the method includes:

The network side device uses all time domain signal paths except the user signal window in the target cell as the interference noise window;

The network side device performs noise power estimation according to a time domain signal path in the interference noise window.

The accuracy of the noise power estimation is improved by using all time domain signal paths outside the user signal window in the target cell as the interference noise window.

Preferably, the network side device determines the user signal window according to the following manner:

The network side device determines the length of the user signal window according to the number of user equipments multiplexed on the same PRB and the maximum signal window value in all cells currently managed by the network side device;

The network side device selects a user signal window in the target cell according to the length of the user signal window.

Preferably, the user signal window selected by the network side device does not include the same time domain signal path as the user signal window of the specific cell;

The specific cell is an interference cell of the target cell, and is managed by the network side device.

By selecting the user signal window in the above manner, it is possible to prevent the user signal window of the target cell from being interfered by the user signal in the specific cell.

Preferably, the performing noise power estimation according to the time domain signal path in the interference noise window comprises:

Taking an average value of power values of all time domain signal paths in the interference noise window as a noise power value; or

And using, as the noise power value, an average value of the power value of the time domain signal path that is smaller than the threshold in the interference noise window; or

The average value of the power values of the smallest N time domain signal paths in the interference noise window is taken as the noise power value, and N is a positive integer.

Preferably, after the network side device performs the noise power estimation according to the time domain signal path in the interference noise window, the method further includes:

The network side device uses the noise power value obtained by estimating the noise power as a threshold value of the effective time domain signal path used for channel estimation.

Since the noise power value is relatively accurate, the interference noise value is directly used as the threshold value for determining the effective time domain signal path, which can prevent some real time domain signal paths from being missed when the effective time domain signal path is selected, thereby improving channel estimation. The accuracy.

The embodiment of the invention further provides a network side device for estimating noise power, and the device includes:

a window finder module, configured to use all time domain signal paths except the user signal window in the target cell as an interference noise window;

And a processing module, configured to perform noise power estimation according to a time domain signal path in the interference noise window.

The accuracy of the noise power estimation is improved by using all time domain signal paths outside the user signal window in the target cell as the interference noise window.

Preferably, the window finder module is further configured to determine a user signal window according to the following manner:

Determining the length of the user signal window according to the number of user equipments currently accessed in all cells managed by the network side device, and the maximum signal window value;

According to the length of the user signal window, a user signal window is selected in the target cell.

Preferably, the user signal window selected by the window finder module does not include the same time domain signal path as the user signal window of the specific cell;

The specific cell is an interference cell of the target cell, and is managed by the network side device.

By selecting the user signal window in the above manner, it is possible to prevent the user signal window of the target cell from being interfered by the user signal in the specific cell.

Preferably, the processing module is specifically configured to:

Taking an average value of power values of all time domain signal paths in the interference noise window as a noise power value; or

And using, as the noise power value, an average value of the power value of the time domain signal path that is smaller than the threshold in the interference noise window; or

The average value of the power values of the smallest N time domain signal paths in the interference noise window is taken as the noise power value, and N is a positive integer.

Preferably, the processing module is further configured to:

After the noise power estimation is performed according to the time domain signal path in the interference noise window, the noise power value obtained by estimating the noise power is used as the threshold value of the effective time domain signal path used for channel estimation.

Since the noise power value is relatively accurate, the interference noise value is directly used as the threshold value for determining the effective time domain signal path, which can prevent some real time domain signal paths from being missed when the effective time domain signal path is selected, thereby improving channel estimation. The accuracy.

The embodiment of the invention further provides a network side device for estimating noise power, and the device includes:

a processor, configured to use all time domain signal paths except the user signal window in the target cell as an interference noise window; and perform noise power estimation according to a time domain signal path in the interference noise window;

A transceiver for receiving and transmitting data under the control of a processor.

The noise power estimation is improved by using all time domain signal paths except the user signal window in the target cell as the interference noise window. Accuracy of the meter.

Preferably, the processor is specifically configured to:

After determining that the UE needs to be self-configured, the control transceiver sends information indicating that the UE needs to perform self-configuration to the network side device.

Preferably, the processor is further configured to determine the user signal window according to the following manner:

Determining the length of the user signal window according to the number of user equipments currently accessed in all cells managed by the network side device, and the maximum signal window value;

According to the length of the user signal window, a user signal window is selected in the target cell.

Preferably, the user signal window selected by the processor does not include the same time domain signal path as the user signal window of the specific cell; wherein the specific cell is the interference cell of the target cell, and is managed by the same network side device.

By selecting the user signal window in the above manner, it is possible to prevent the user signal window of the target cell from being interfered by the user signal in the specific cell.

Preferably, the processor is specifically configured to:

The average value of the power values of all time domain signal paths in the interference noise window is taken as the noise power value; or

The average value of the power values of the time domain signal path that is less than the threshold within the noise window is used as the noise power value; or

The average value of the power values of the smallest N time domain signal paths in the interference noise window is taken as the noise power value, and N is a positive integer.

Preferably, the processor is further configured to:

After the noise power estimation is performed according to the time domain signal path in the interference noise window, the noise power value obtained by estimating the noise power is used as the threshold value of the effective time domain signal path used for channel estimation.

By selecting the user signal window in the above manner, it is possible to prevent the user signal window of the target cell from being interfered by the user signal in the specific cell.

Since the noise power value is relatively accurate, the interference noise value is directly used as the threshold value for determining the effective time domain signal path, which can prevent some real time domain signal paths from being missed when the effective time domain signal path is selected, thereby improving channel estimation. The accuracy.

DRAWINGS

1 is a flow chart of a channel estimation method in the background art;

2 is a schematic diagram of a user signal window and an interference noise window selected when performing noise power estimation in the background art;

3 is a schematic structural diagram of a network side device for estimating noise power according to Embodiment 1 of the present application;

4 is a schematic structural diagram of a network side device for estimating noise power according to Embodiment 2 of the present application;

FIG. 5 is a flowchart of a method for estimating noise power according to Embodiment 4 of the present application;

6 is a flowchart of a method for estimating noise power according to Embodiment 5 of the present application;

7 is a schematic diagram of a user signal window and an interference noise window selected in Embodiment 5 of the present application;

8 is a flowchart of a method for estimating noise power according to Embodiment 6 of the present application;

9 is a schematic diagram of a user signal window and an interference noise window selected in Embodiment 6 of the present application;

10 is a flowchart of a method for estimating noise power provided in Embodiment 7 of the present application;

11 is a schematic diagram of a user signal window and an interference noise window selected in Embodiment 7 of the present application;

12 is a flowchart of a channel estimation method according to Embodiment 8 of the present application;

In Figures 2, 7, 9, and 11, the X-axis represents the time domain index value corresponding to the time domain channel estimate, and the Y-axis represents the time domain channel estimate.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

It should be understood that the technical solution of the present invention can be applied to various communication systems, for example, a Global System of Mobile communication (GSM) system, a Code Division Multiple Access (CDMA) system, and a wideband code division. Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, Advanced Long Term Evolution (LTE-A) System, Universal Mobile Telecommunication System (UMTS), etc.

It should be understood that, in the embodiment of the present invention, the user equipment (User Equipment, UE) includes but is not limited to a mobile station (MS, Mobile Station), a mobile terminal (Mobile Terminal), a mobile telephone (Mobile Telephone), a mobile phone (handset). And portable devices, etc., the user equipment can communicate with one or more core networks via a Radio Access Network (RAN), for example, the user equipment can be a mobile phone (or "cellular" The telephone device, the computer with wireless communication function, etc., the user equipment can also be a mobile device that is portable, pocket-sized, handheld, built-in, or in-vehicle.

In an embodiment of the invention, a base station (e.g., an access point) may refer to a device in an access network that communicates with a wireless terminal over one or more sectors over an air interface. The base station can be used to convert the received air frame to the IP packet as a router between the wireless terminal and the rest of the access network, wherein the remainder of the access network can include an Internet Protocol (IP) network. The base station can also coordinate attribute management of the air interface. For example, the base station may be a Base Transceiver Station (BTS) in GSM or CDMA, or may be a base station (NodeB) in WCDMA, or may be an evolved base station in LTE (NodeB or eNB or e-NodeB, evolutional Node B), the invention is not limited.

In this embodiment, when the interference noise window is selected, all time domain signal paths except the user signal window in the target cell are used as interference noise windows, and noise power estimation is performed according to the time domain signal path in the interference noise window. Since the window length of the selected interference noise window is large, the problem that the calculated interference noise power is larger than the actual interference noise power due to the interference noise window containing only one interference cell signal is avoided, and the interference noise window can be The inclusion of all possible specific interfering cell signals is statistically more accurate, so the estimated interference noise power is closer to the real interfering noise power value, thereby improving the accuracy of the channel estimation.

The embodiments of the present application are further described in detail below with reference to the accompanying drawings.

As shown in FIG. 3, the structure of the network side device for estimating the noise power of the first embodiment of the present application includes:

The window finder module 300 is configured to use all time domain signal paths except the user signal window in the target cell as an interference noise window;

The processing module 310 is configured to perform noise power estimation according to a time domain signal path in the interference noise window.

The window finder module 300 is further configured to determine a user signal window according to the following manner:

The length of the user signal window is determined according to the number of user equipments currently accessed in all cells managed by the network side device, and the maximum signal window value:

(Formula 1);

The number of user equipments in all the cells managed by the network side device is currently accessed by the N _{user, the total} user equipment of the cells is multiplexed on the same physical resource block (PRB), and the WLen _Ref is the largest. The signal window value can be set according to the sum of the timing deviation measured by the network side device and the maximum multipath delay, or can be pre-configured by the network side device, length (Win _Sig ) represents the length of the user signal window, and N _PRB represents the allocation. PRB values to the user. The total number of time domain resources available to the user equipment in this embodiment is 12N _PRB .

The windowing module 300 then selects a user signal window in the target cell based on the length of the user signal window.

The user signal window Win _Sig and the interference noise window Win _Noise can be selected as follows:

User signal window:

Win _Sig = [-M ₁ + α, M ₂ + α-1] mod (12N _PRB ) (Formula 2);

Interference noise window:

Win _Noise = [M ₂ + α, M ₂ + α + M ₃ -1] mod (12N _PRB ) (Formula 3);

Where α represents the phase offset of the user's DeModulation Reference Signal (DMRS) symbol, M ₁ and M ₂ represent the front and rear window sizes of the user signal window, respectively, and M ₃ represents the window length of the interference noise window. The values of M ₁ , M ₂ and M ₃ are directly configured by the network side device, and mod (·) represents the modulo operation.

Since all the time domain signal paths except the user signal window in the target cell are used as the interference noise window in the embodiment of the present application, M _{3 is} automatically determined after determining the user signal window, and thus the configuration parameters α, M ₁ and M ₂ can be configured. Determine the position of the user signal window and the interference noise window in the time domain.

Preferably, the user signal window selected by the windowing module does not include the same time domain signal path as the user signal window of the specific cell; wherein, the specific cell is the interference cell of the target cell, and is managed by the same network side device. Thereby, it is possible to prevent signals of other users in a specific cell from being included in the user signal window of the target cell.

The network side device in the embodiment of the present application may be a type of base station, such as a macro base station, a home base station, or the like, or a relay node (RN) device, or other network side devices.

After the interference noise window is selected, the processing module 310 may perform the noise power estimation on the time domain signal path in the interference noise window in a plurality of manners to obtain the noise power value, which may include, but is not limited to, the following methods:

In the first method, the average value of the power values of all the time domain signal paths in the interference noise window is taken as the noise power value, and the specific processing manner is as follows:

Record the time domain signal path in the interference noise window of the target cell as h' _i (i = 0, 1, ... WL _n -1), and calculate the interference noise power Power _{NI as} follows:

Among them, real(·) and imag(·) represent the real part and the imaginary part, respectively.

In the second mode, the average value of the power values of the time domain signal path that is less than the threshold in the noise window is used as the noise power value. In this mode, the threshold value is used to filter the power value of the excessive time domain signal path to avoid excessively obtained noise power value. The specific processing manner is as follows:

Record the time domain signal path in the interference noise window of the target cell as h' _i (i = 0, 1, ... WL _n -1), and each time domain signal path h' _i (i = 0, 1, ... WL _n -1) is compared with the threshold h ₀ , and the time domain signal path smaller than the threshold h ₀ is reserved, and h _i (i=0,1,...WL _n -N'-1) is obtained, and then the interference noise power is calculated according to the following formula: Power _NI :

Where real(·) and imag(·) represent the real part and the imaginary part, respectively, and N' represents the number of time domain signal paths excluded after comparison with the threshold, and N' is a non-negative integer.

In the third mode, the average value of the power values of the smallest N time domain signal paths in the interference noise window is taken as the noise power value, where N is a positive integer. In general, N can be set to half of the total number of time domain signal paths in the interference noise window. When the total number of signal path samples in the field is small, N can be set to exceed half of the total time domain signal path in the interference noise window. Positive integers to improve the accuracy of noise power values. The specific treatment is as follows:

Record the time domain signal path in the interference noise window of the target cell as h' _i (i = 0, 1, ... WL _n -1), and sort the time domain signal path of the interference noise window according to the power from small to large: h _i =sort(h' _i ), where sort(·) indicates sorting from small to large.

Select the smallest N time domain signal paths and calculate the interference noise power Power _{NI as} follows:

Among them, real(·) and imag(·) represent the real part and the imaginary part, respectively, and N is a positive integer.

In addition, the processing module 310 is further configured to:

After the noise power estimation is performed according to the time domain signal path in the interference noise window, the noise power value obtained by estimating the noise power is used as the threshold value of the effective time domain signal path used for channel estimation.

As shown in FIG. 4, the structure of the network side device for estimating the noise power of the second embodiment of the present application includes:

The processor 400 is configured to use all time domain signal paths except the user signal window in the target cell as an interference noise window; and perform noise power estimation according to the time domain signal path in the interference noise window;

The transceiver 410 is configured to receive and transmit data under the control of the processor 400.

Preferably, the processor 400 is specifically configured to:

After determining that the UE needs to be self-configured, the control transceiver 410 transmits information indicating that the UE needs to perform self-configuration to the network side device.

Preferably, the processor 400 is further configured to determine a user signal window according to the following manner:

Determining the length of the user signal window according to the number of user equipments currently accessed in all cells managed by the network side device, and the maximum signal window value;

According to the length of the user signal window, a user signal window is selected in the target cell.

Preferably, the user signal window selected by the processor 400 does not include the same time domain signal path as the user signal window of the specific cell; wherein the specific cell is the interfering cell of the target cell, and is managed by the same network side device.

Preferably, the processor 400 is specifically configured to:

The average value of the power values of all time domain signal paths in the interference noise window is taken as the noise power value; or

The average value of the power values of the time domain signal path that is less than the threshold within the noise window is used as the noise power value; or

The average value of the power values of the smallest N time domain signal paths in the interference noise window is taken as the noise power value, and N is a positive integer.

Preferably, the processor 400 is further configured to:

After the noise power estimation is performed according to the time domain signal path in the interference noise window, the noise power value obtained by estimating the noise power is used as the threshold value of the effective time domain signal path used for channel estimation.

4, the bus architecture can include any number of interconnected buses and bridges, specifically linked by one or more processors represented by processor 400 and various circuits of memory represented by memory 420. The bus architecture can also link various other circuits such as peripherals, voltage regulators, and power management circuits, which are well known in the art and, therefore, will not be further described herein. The bus interface provides an interface. The transceiver 410 can be a plurality of components, including a transmitter and a receiver, for providing communication with various other devices on a transmission medium. unit. The processor 400 is responsible for managing the bus architecture and general processing, and the memory 420 can store data used by the processor 400 when performing operations.

The processor 400 is responsible for managing the bus architecture and general processing, and the memory 420 can store data used by the processor 400 when performing operations.

The third embodiment of the present application further provides a channel estimation system, which includes any network side device of noise power estimation mentioned in Embodiment 1 and Embodiment 2. The network side device of the noise power estimation in the channel estimation system uses the noise power value as the threshold value of the effective time domain signal path used for channel estimation, and then the channel estimation system performs the channel according to the threshold value. estimate. The specific processing manner of the channel estimation system for performing channel estimation according to the threshold value includes, but is not limited to, the manner mentioned in the background art, and any other applicable prior art may be adopted.

Since the method of obtaining the noise power value is optimized, the threshold value when the effective time domain signal path is selected is relatively accurate compared with the prior art, which can reduce the partial real time domain signal path when the effective time domain signal path is selected. The possibility to improve the accuracy of channel estimation.

Based on the same inventive concept, a noise estimation method and a channel estimation method are separately provided in the embodiments of the present application, and the device corresponding to the methods is a network side device and a channel estimation system for noise estimation in the embodiment of the present application, and the method The principle of solving the problem is similar to that of the device. Therefore, the implementation of the method can be referred to the corresponding implementation in the device, and the repeated description is not repeated.

As shown in FIG. 5, the method for estimating noise power provided in Embodiment 4 of the present invention includes:

Step 501: The network side device uses all time domain signal paths except the user signal window in the target cell as an interference noise window.

Step 502: The network side device performs noise power estimation according to a time domain signal path in the interference noise window.

Preferably, the network side device determines the user signal window according to the following manner:

The network side device determines the length of the user signal window according to the number of user equipments in all cells currently managed by the network side device and the maximum signal window value;

The network side device selects a user signal window in the target cell according to the length of the user signal window.

Preferably, the user signal window selected by the network side device does not include the same time domain signal path as the user signal window of the specific cell; wherein the specific cell is the interference cell of the target cell, and is managed by the network side device.

Preferably, the noise power estimation is performed according to a time domain signal path within the interference noise window, including:

The average value of the power values of all time domain signal paths in the interference noise window is taken as the noise power value; or

The average value of the power values of the time domain signal path that is less than the threshold within the noise window is used as the noise power value; or

The average value of the power values of the smallest N time domain signal paths in the interference noise window is taken as the noise power value, and N is a positive integer.

Preferably, after the network side device performs the noise power estimation according to the time domain signal path in the interference noise window, the method further includes:

The network side device uses the noise power value obtained by estimating the noise power as the threshold value of the effective time domain signal path used for channel estimation.

As shown in FIG. 6, the method for estimating noise power provided in Embodiment 5 of the present invention includes:

Step 601: The network side device determines the length of the user signal window length (Win _Sig ) according to the number N _{user, total} , and the maximum signal window value WLen _Ref of all the user equipments currently accessed to the network side device. .

In this embodiment, the number of cells managed by the network side device is three, N _{user, total} = 6, and WLen _{Ref is} preset to 3N _PRB .

It is thus determined that the user signal window length is 2N _PRB .

Step 602: The network side device selects a user signal window in the target cell according to the length of the user signal window. In a specific implementation, the user signal window can be selected according to Equation 2 by setting appropriate parameters α, M ₁ and M ₂ . When the user signal window is selected, the distance between the two user signal windows in the same cell is maximized in the time domain to ensure that the selected user signal window does not include the same time domain signal path as the user signal window of the specific cell. The specific cell is an interfering cell of the target cell, and is managed by the same network side device.

The user signal window finally selected in this embodiment is as follows:

Cell 1: user signal of user 1 occupies the window [0,2N _PRB -1], the user signals the user 2 occupies the window _{[2N PRB, 8N PRB -1]} ;

In cell 2, the user signal window of user 1 occupies [2N _PRB , 4N _PRB -1], and the user signal window of user 2 occupies [8N _PRB , 10N _PRB -1];

In cell 3, the user signal window of user 1 occupies [4N _PRB , 6N _PRB -1], and the user signal window of user 2 occupies [10N _PRB , 12N _PRB -1].

Example embodiments of the present disclosure, the user signal window numbered from zero, [0,2N _PRB -1] indicates the number of signal path 2N _PRB from 0 to 2N _PRB -1 time domain.

Step 603: The network side device uses all time domain signal paths except the user signal window in the target cell as the interference noise window:

In cell 1, the interference noise window Win _{Noise, cell1} occupies [2N _PRB , 6N _PRB -1 ] ∪ [8N _PRB , 12N _PRB -1 ], and the window length is WL _n = length (Win _{Noise, cell1} ) = 8N _PRB ;

In cell 2, the interference noise window Win _{Noise, cell2} occupies [0 _{, 2N PRB} -1] ∪ [4N _PRB , 8N _PRB -1] ∪ [10N _PRB , 12N _PRB -1], and the window length is WL _n = length (Win _{Noise, cell2} ) = 8N _PRB ;

In cell 3, the interference noise window Win _{Noise, cell3} occupies [0, 4N _PRB -1] ∪ [6N _PRB , 10N _PRB -1], and the window length is WL _n = length (Win _{Noise, cell3} ) = 8N _PRB ;

So far, the user signal window and the interference noise window selected in this embodiment are as shown in FIG. 7.

Step 604, the average value of the power values of all time domain signal paths in the interference noise window is taken as the noise power value.

With cell 1 as the target cell, the time domain signal path in the interference noise window is h' _i (i = 0, 1, ... WL _n -1), and the interference noise power Power _{NI is} calculated as follows:

Among them, real(·) and imag(·) represent the real part and the imaginary part, respectively.

As shown in FIG. 8, the noise power estimation method provided in Embodiment 6 of the present invention includes:

Step 801: The network side device determines the length of the user signal window length (Win _Sig ) according to the number N _{user, total} , and the maximum signal window value WLen _Ref of all the user equipments currently accessed to the network side device. .

In this embodiment, the number of cells managed by the network side device is two, N _{user, total} = 4, and WLen _{Ref is} preset to 3N _PRB .

This determines the user signal window length to be 3N _PRB .

Step 802: The network side device selects a user signal window in the target cell according to the length of the user signal window. In a specific implementation, the user signal window can be selected according to Equation 2 by setting appropriate parameters α, M ₁ and M ₂ . When the user signal window is selected, the distance between the two user signal windows in the same cell is maximized in the time domain to ensure that the selected user signal window does not include the same time domain signal path as the user signal window of the specific cell. The specific cell is an interfering cell of the target cell, and is managed by the same network side device.

The user signal window finally selected in this embodiment is as follows:

In cell 1: user 1's user signal window occupies [0, 3N _PRB -1], user 2's user signal window occupies [6N _PRB , 9N _PRB -1];

In cell 2, the user signal window of user 1 occupies [3N _PRB , 6N _PRB -1], and the user signal window of user 2 occupies [9N _PRB , 12N _PRB -1];

Step 803: The network side device uses all time domain signal paths except the user signal window in the target cell as the interference noise window:

In cell 1, the interference noise window Win _{Noise, cell1} occupies [3N _PRB , 6N _PRB -1 ] ∪ [9N _PRB , 12N _PRB -1 ], and the window length is WL _n = length (Win _{Noise, cell1} ) = 6N _PRB ;

In cell 2, the interference noise window Win _{Noise, cell2} occupies [0, 3N _PRB -1] ∪ [9N _PRB , 12N _PRB -1], and the window length is WL _n = length (Win _{Noise, cell 2} ) = 6N _PRB ;

So far, the user signal window and the interference noise window selected in this embodiment are as shown in FIG. 9.

Step 804, the average value of the power values of the time domain signal paths smaller than the threshold in the interference noise window is used as the noise power value.

With cell 1 as the target cell, the time domain signal path in the interference noise window is h' _i (i = 0, 1, ... WL _n -1), and each time domain signal path h' _i (i = 0, 1,... WL _n -1) is compared with the threshold h ₀ , and the time domain signal path smaller than the threshold h ₀ is retained, and h _i (i=0,1,...WL _n -N'-1) is obtained, and then Calculate the interference noise power Power _NI :

Where real(·) and imag(·) represent the real part and the imaginary part, respectively, and N' represents the number of time domain signal paths excluded after comparison with the threshold, and N' is a non-negative integer.

As shown in FIG. 10, the method for estimating noise power provided in Embodiment 7 of the present invention includes:

Step 1001: The network side device determines the length of the user signal window length (Win _Sig ) according to the number N _{user, total} , and the maximum signal window value WLen _Ref of all the user equipments currently accessed to the network side device. .

In this embodiment, the number of cells managed by the network side device is two, N _{user, total} = 4, and WLen _{Ref is} preset to 3N _PRB .

This determines the user signal window length to be 3N _PRB .

Step 1002: The network side device selects a user signal window in the target cell according to the length of the user signal window. In a specific implementation, the user signal window can be selected according to Equation 2 by setting appropriate parameters α, M ₁ and M ₂ . When the user signal window is selected, the distance between the two user signal windows in the same cell is maximized in the time domain to ensure that the selected user signal window does not include the same time domain signal path as the user signal window of the specific cell. The specific cell is an interference cell of the target cell, and is managed by the network side device.

The user signal window finally selected in this embodiment is as follows:

In cell 1, the user signal window of user 1 occupies [0, 2N _PRB -1] ∪ [11N _PRB , 12N _PRB -1], and the user signal window of user 2 occupies [5N _PRB , 8N _PRB -1];

In cell 2, the user signal window of user 1 occupies [2N _PRB , 5N _PRB -1], and the user signal window of user 2 occupies [8N _PRB , 11N _PRB -1];

Step 1003: The network side device uses all time domain signal paths except the user signal window in the target cell as the interference noise window:

In cell 1, the interference noise window Win _{Noise, cell1} occupies [2N _PRB , 5N _PRB -1] ∪ [8N _PRB , 11N _PRB -1], and the window length is WL _n = length (Win _{Noise, cell1} ) = 6N _PRB ;

In cell 2, the interference noise window Win _{Noise, cell2} occupies [0 _{, 2N PRB} -1] ∪ [5N _PRB , 8N _PRB -1] ∪ [11N _PRB , 12N _PRB -1], and the window length is WL _n = length (Win _{Noise, cell2} ) = 6N _PRB ;

So far, the user signal window and the interference noise window selected in this embodiment are as shown in FIG.

Step 1004: The average value of the power values of the smallest N time domain signal paths in the interference noise window is taken as the noise power value.

Taking cell 1 as the target cell, the time domain signal path in the interference noise window is h' _i (i = 0, 1, ... WL _n -1), and the time domain signal path of the interference noise window is performed according to the power from small to large. Sort: h _i =sort(h' _i ), where sort(·) indicates sorting from small to large.

Select the smallest N time domain signal paths and calculate the interference noise power Power _{NI as} follows:

Among them, real(·) and imag(·) represent the real part and the imaginary part, respectively, and N is a positive integer.

As shown in FIG. 12, a channel estimation method according to Embodiment 8 of the present invention obtains a noise power value by using any noise power estimation method provided by an embodiment of the present application, and performs channel estimation according to the obtained noise power value. Proceed as follows:

Step 1201: Perform LS channel estimation in the frequency domain, divide the received pilot symbols in the frequency domain and the local pilot base sequence to obtain an initial frequency domain channel estimation value.

The signal model used in this step is the frequency domain equivalent receiving channel model of the LTE uplink SIMO:

Y _P =diag{X _P }H _P +W _P

Y _P represents the received pilot signal vector, X _P denotes a transmission pilot signal vector, H _P represents the frequency domain channel response vector, W _P represents received noise vector, diag {X _P} represents the elements in the main diagonal X _P The diagonal matrix of the elements.

Thereby, the initial frequency domain channel estimation value is obtained.

for:

Step 1202: Perform an IDFT transform of the initial frequency domain channel estimation value by N points to obtain a time domain channel estimation sequence before processing.

Where F ^H represents a normalized IDFT matrix.

Step 1203, estimating a time domain channel sequence

A window-suppressing operation is performed to obtain a time-domain channel estimation sequence h' _P (n) after noise suppression.

The step 1203 specifically includes:

Step 12031: Acquire a noise power value by using any noise power estimation method provided by the embodiment of the present application.

Step 12032, directly using the noise power value as a threshold TH for determining an effective time domain signal path;

As an alternative manner, in this step, the method for determining the threshold TH of the effective time domain signal path according to the strongest time domain signal path and the noise power value in the user signal window in the prior art may also be adopted:

TH=min(β·Power _NI , γ·P _h,max )

among them,

The power value representing the strongest time domain signal path within the user signal window, β and γ are algorithm parameters.

Step 12033: Filter the time domain signal path that needs to be reserved in the user signal window according to the threshold value, and set the time domain signal path that does not need to be reserved to zero:

among them,

To preserve the time domain signal path within the user signal window, Win _Sig represents the user signal window.

Step 12034, the time domain signal path in the noise window is set to zero, and the time domain channel estimation sequence h' _P (n) after the noise suppression is obtained:

Among them, Win _Sig represents the user signal window, and Win _Noise represents the interference noise window.

Step 1204: Perform DFT on the noise-suppressed time domain channel estimation sequence to obtain a frequency domain channel estimation value H′ _{P of the} pilot symbol:

Where F represents the normalized DFT matrix.

Step 1205: Perform time domain linear interpolation on the frequency domain channel estimation value of the pilot symbol to obtain a frequency domain channel estimation value H′ _{Data of the} data symbol, and the specific interpolation algorithm may adopt an LS or MMSE linear interpolation algorithm.

It can be seen from the above that when the interference noise window is selected, all the time domain signal paths except the user signal window in the target cell are used as the interference noise window, which can improve the estimation accuracy of the interference noise value. The algorithm for adjusting the estimation of the interference noise value further improves the accuracy, and directly uses the interference noise value as the threshold value for determining the effective time domain signal path in the channel estimation, so that the accuracy of the channel estimation is also improved. In addition, by optimizing the scheme of selecting the user signal window, the user signal window of the target cell is prevented from being interfered by the user signal in the specific cell, which further improves the accuracy of the channel estimation.

Those skilled in the art will appreciate that embodiments of the present invention can be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or a combination of software and hardware. Moreover, the invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) including computer usable program code.

The present invention is directed to a flowchart of a method, apparatus (system), and computer program product according to an embodiment of the present invention. And / or block diagram to describe. It will be understood that each flow and/or block of the flowchart illustrations and/or FIG. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing device to produce a machine for the execution of instructions for execution by a processor of a computer or other programmable data processing device. Means for implementing the functions specified in one or more of the flow or in a block or blocks of the flow chart.

The computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device. The apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.

These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device. The instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

While the preferred embodiment of the invention has been described, it will be understood that Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and the modifications and

It is apparent that those skilled in the art can make various modifications and variations to the embodiments of the invention without departing from the spirit and scope of the embodiments of the invention. Thus, it is intended that the present invention cover the modifications and modifications of the embodiments of the invention.

Claims (10)

1. A noise power estimation method, the method comprising:

   The network side device uses all time domain signal paths except the user signal window in the target cell as the interference noise window;

   The network side device performs noise power estimation according to a time domain signal path in the interference noise window.
2. The method of claim 1, wherein the network side device determines the user signal window according to the following manner:

   The network side device determines the length of the user signal window according to the number of user equipments multiplexed on the same PRB and the maximum signal window value in all cells currently managed by the network side device;

   The network side device selects a user signal window in the target cell according to the length of the user signal window.
3. The method according to claim 2, wherein the user signal window selected by the network side device does not include the same time domain signal path as the user signal window of the specific cell;

   The specific cell is an interference cell of the target cell, and is managed by the network side device.
4. The method of claim 1, wherein the estimating the noise power according to the time domain signal path in the interference noise window comprises:

   Taking an average value of power values of all time domain signal paths in the interference noise window as a noise power value; or

   And using, as the noise power value, an average value of the power value of the time domain signal path that is smaller than the threshold in the interference noise window; or

   The average value of the power values of the smallest N time domain signal paths in the interference noise window is taken as the noise power value, and N is a positive integer.
5. The method according to any one of claims 1 to 4, wherein after the network side device performs noise power estimation according to the time domain signal path in the interference noise window, the method further includes:

   The network side device uses the noise power value obtained by estimating the noise power as a threshold value of the effective time domain signal path used for channel estimation.
6. A network side device for estimating noise power, characterized in that the device comprises:

   a window finder module, configured to use all time domain signal paths except the user signal window in the target cell as an interference noise window;

   And a processing module, configured to perform noise power estimation according to a time domain signal path in the interference noise window.
7. The device according to claim 6, wherein the window finder module is further configured to determine a user signal window according to the following manner:

   Determining the length of the user signal window according to the number of user equipments currently accessed in all cells managed by the network side device, and the maximum signal window value;

   According to the length of the user signal window, a user signal window is selected in the target cell.
8. The device according to claim 7, wherein the user signal window selected by the window finder module does not include the same time domain signal path as the user signal window of the specific cell;

   The specific cell is an interference cell of the target cell, and is managed by the network side device.
9. The device according to claim 6, wherein the processing module is specifically configured to:

   Taking an average value of power values of all time domain signal paths in the interference noise window as a noise power value; or

   And using, as the noise power value, an average value of the power value of the time domain signal path that is smaller than the threshold in the interference noise window; or

   The average value of the power values of the smallest N time domain signal paths in the interference noise window is taken as the noise power value, and N is a positive integer.
10. The device according to any one of claims 6 to 9, wherein the processing module is further configured to:

    After the noise power estimation is performed according to the time domain signal path in the interference noise window, the noise power value obtained by estimating the noise power is used as the threshold value of the effective time domain signal path used for channel estimation.

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