A method and system for removing direct current from a receiver

Abstract

The present application discloses a method and system for removing direct current from a receiver, and relates to the field of communication systems. The method comprises: obtaining target signal data; eliminating the k-1th direct current signal data from the k-th target signal data to obtain the target signal data after the k-th direct current is eliminated; performing loop filter operation on the target signal data after the k-th and k-1th direct current is eliminated, and the k-th and k-1th target signal data to determine the k-th direct current signal data; based on the k+1th target signal data and the k-th direct current signal data, returning to execute the step of "eliminating the k-1th direct current signal data from the k-th target signal data to obtain the target signal data after the k-th direct current is eliminated", until k is equal to the total length of the target signal data. The present application enables the receiver to quickly and effectively eliminate direct current signals.

Description

Technical Field

[0001] The present application relates to the technical field of communication systems, and in particular to a method and system for removing direct current from a receiver. Background Art

[0002] In communication systems, the receiver is often interfered by DC signals while receiving the target signal. The interference of DC signals will affect the performance of the receiver to a certain extent, so how to avoid the interference of DC signals on the receiver is crucial.

[0003] The existing technology generally adopts methods such as maximum likelihood (ML) estimation to remove DC and average DC to avoid the interference of DC signals on the receiver. On the one hand, the ML estimation method of removing DC is relatively complex and is not conducive to implementation; on the other hand, the average DC removal method has good performance for some communication systems, such as the Global System For Mobile Communications (GSM), but the effect is not obvious for some broadband communication systems. At the same time, in order to accurately calculate the DC signal, the average DC removal method also requires a large delay. Summary of the invention

[0004] The purpose of the present application is to provide a receiver DC removal method and system, which can enable the receiver to quickly and effectively eliminate DC signals.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a method for removing direct current from a receiver, the method comprising:

[0007] Acquire target signal data; wherein the target signal data is mixed with DC signal data;

[0008] Eliminating the k-1th DC signal data from the kth target signal data to obtain the kth target signal data after DC elimination; wherein the initial value of the DC signal data is determined according to the average value of n segments of target signal data of set length; n>1 and k>n+1;

[0009] Performing loop filter operation on the kth and k-1th DC-eliminated target signal data, and the kth and k-1th target signal data, to determine the kth DC signal data;

[0010] Based on the k+1th target signal data and the kth DC signal data, return to the execution step of "eliminating the k-1th DC signal data from the kth target signal data to obtain the kth DC-eliminated target signal data" until k is equal to the total length of the target signal data.

[0011] Optionally, the calculation formula of the kth target signal data after DC elimination is:

[0012] data_out(k)=data(k)-Dc_cal(k-1);

[0013] Wherein, data_out(k) is the k-th target signal data after DC elimination, data(k) is the k-th target signal data, and Dc_cal(k-1) is the k-1-th DC signal data.

[0014] Optionally, the initial value of the DC signal data is determined according to an average value of n segments of target signal data of a set length, specifically including:

[0015] Get n segments of target signal data of set length;

[0016] Calculate the average value of target signal data of each set length respectively to obtain n target signal average values;

[0017] The initial value of the DC signal is obtained by summing the average values ​​of the n signals.

[0018] Optionally, the calculation formula for the average value of the nth target signal is:

[0019] DC n =(data(1)+…+data(dataLen n )) / dataLen n ;

[0020] Where, DC n is the average value of the nth target signal, dataLen n is the nth set length, data(1) is the first data in the target signal data of the nth set length, data(dataLen n ) is the last data in the target signal data of the set length of the nth segment.

[0021] Optionally, the calculation formula of the initial value of the DC signal is:

[0022] Dc_cal=DC1+…+DC n ;

[0023] Where Dc_cal is the initial value of the DC signal, DC1 is the average value of the first target signal, and DCn is the average value of the nth target signal.

[0024] Optionally, the calculation formula for the kth DC signal data is:

[0025]

[0026] Wherein, Dc_cal(k) is the kth DC signal data, K is the loop filter parameter, data_out(k) is the kth target signal data after DC elimination, and data(k) is the kth target signal data.

[0027] Optionally, the value of K is determined according to the bandwidth of the communication system; the bandwidth of the communication system is inversely proportional to the value of K.

[0028] Optionally, the value of K is 7, 12, 16 or 20.

[0029] Optionally, when the bandwidth of the communication system changes, the initial value of the DC signal also changes, and the receiver DC removal method needs to be re-executed.

[0030] In a second aspect, the present application further provides a receiver DC removal system, the receiver DC removal system comprising at least: an ADC sampling module, a receiver controller and a loop filter;

[0031] The ADC sampling module is used to obtain target signal data; the target signal data is mixed with DC signal data;

[0032] The receiver controller is connected to the ADC sampling module; the receiver controller is used to eliminate the k-1th DC signal data from the kth target signal data to obtain the kth DC-eliminated target signal data; wherein the initial value of the DC signal data is determined according to the average value of n segments of target signal data of set length; n>1 and k>n+1;

[0033] The loop filter is connected to the receiver controller; the loop filter is used to perform loop filter operations on the kth and k-1th DC-eliminated target signal data, and the kth and k-1th target signal data to determine the kth DC signal data;

[0034] The receiver controller is also used to return to the execution step of "eliminating the k-1th DC signal data from the kth target signal data to obtain the kth DC-eliminated target signal data" based on the k+1th target signal data and the kth DC signal data, until k is equal to the total length of the target signal data.

[0035] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0036] The present application determines the initial value of the DC signal by only using the average value of the target signal data of n segments of set length, without requiring a large time delay, and to a certain extent, realizes the rapid response of the receiver. At the same time, after determining the initial value of the DC signal, the present application also continuously eliminates the previous DC signal data from the target signal data, and further calculates the next DC signal data by introducing a loop filter, and repeats this cycle until the DC signal in all target signal data is eliminated. The cyclic operation process of the loop filter and the DC signal effectively eliminates the interference of the DC signal on the receiver. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0038] Figure 1 A flowchart of a method for removing DC from a receiver provided in an embodiment of the present application;

[0039] Figure 2 A schematic diagram of the structure of a receiver DC removal system provided in an embodiment of the present application;

[0040] Figure 3 An execution relationship diagram of a receiver DC removal method provided in an embodiment of the present application;

[0041] Figure 4 This is a diagram of the internal operation relationship of the loop filter provided in an embodiment of the present application.

[0042] Explanation of symbols:

[0043] ADC sampling module-1, receiver controller-2, loop filter-3. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0045] The purpose of the present application is to provide a receiver DC removal method and system, which can enable the receiver to quickly and effectively eliminate DC signals.

[0046] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0047] Example 1

[0048] This embodiment provides a method for removing DC from a receiver, such as Figure 1 As shown, the receiver DC removal method specifically includes:

[0049] Step S1: acquiring target signal data (ie, external signal data received by a receiver); direct current signal data is mixed in the target signal data.

[0050] Step S2: Eliminate the k-1th DC signal data from the kth target signal data to obtain the kth target signal data after DC elimination; wherein the initial value of the DC signal data is determined according to the average value of n segments of target signal data of a set length; n>1 and k>n+1.

[0051] In this embodiment, the calculation formula of the kth target signal data after DC elimination is:

[0052] data_out(k)=data(k)-Dc_cal(k-1);

[0053] Wherein, data_out(k) is the k-th target signal data after DC elimination, data(k) is the k-th target signal data, and Dc_cal(k-1) is the k-1-th DC signal data.

[0054] Furthermore, the process of determining the initial value of the DC signal data in the above formula is as follows:

[0055] The first step is to obtain n segments of target signal data of set length.

[0056] In one example, n=2.

[0057] The second step is to calculate the average value of each target signal data of the set length to obtain n target signal average values; wherein, the calculation formula for the nth target signal average value is:

[0058] DC n =(data(1)+…+data(dataLen n )) / dataLen n ;

[0059] Where, DC n is the average value of the nth target signal, dataLen nis the nth set length, data(1) is the first data in the target signal data of the nth set length, data(dataLen n ) is the last data in the target signal data of the set length of the nth segment.

[0060] In one example, k>(dataLen1+…+dataLen n )+1.

[0061] The third step is to obtain the initial value of the DC signal by summing the average values ​​of the n signals; the calculation formula of the initial value of the DC signal is:

[0062] Dc_cal=DC1+…+DC n ;

[0063] Where Dc_cal is the initial value of the DC signal (Dc_cal(k-1)=Dc_cal in the initial operation), DC1 is the average value of the first target signal, and DC n is the average value of the nth target signal.

[0064] Step S3: performing loop filter operation on the kth and k-1th DC-eliminated target signal data, and the kth and k-1th target signal data, to determine the kth DC signal data; wherein the calculation formula of the kth DC signal data is:

[0065]

[0066] Wherein, Dc_cal(k) is the kth DC signal data, and K is the loop filter parameter.

[0067] In this embodiment, it is necessary to determine the value of K according to the bandwidth of the communication system in which the receiver operates. The bandwidth of the communication system is inversely proportional to the value of K, that is, the larger the value of K, the narrower the bandwidth, but the larger the value of K, the more stable the output value of the corresponding filter. Generally, the value of K can be configured to 7, 12, 16 or 20.

[0068] Step S4: Based on the k+1th target signal data and the kth DC signal data, return to execute step S2 until k is equal to (reaches) the total length of the target signal data.

[0069] In this embodiment, by repeatedly executing the above steps S2 to S4, the DC signal data can be continuously eliminated from the target signal data received by the receiver, thereby avoiding the interference of the DC signal on the receiver. In addition, when the bandwidth of the communication system changes during the operation of the receiver, the initial value of the corresponding DC signal also changes. In order to quickly track the signal, the above receiver DC removal method needs to be re-executed to ensure data update.

[0070] Example 2

[0071] This embodiment provides a receiver DC removal system, such as Figure 2 As shown, the receiver DC removal system at least includes: an ADC sampling module 1, a receiver controller 2 and a loop filter 3.

[0072] The ADC sampling module 1 is used to obtain target signal data; the target signal data is mixed with DC signal data;

[0073] The receiver controller 2 is connected to the ADC sampling module 1; the receiver controller 2 is used to eliminate the k-1th DC signal data from the kth target signal data to obtain the kth DC-eliminated target signal data; wherein the initial value of the DC signal data is determined according to the average value of the target signal data of n segments of set length; n>1 and k>n+1;

[0074] The loop filter 3 is connected to the receiver controller 2; the loop filter 3 is used to perform loop filter operations on the kth and k-1th DC-eliminated target signal data, and the kth and k-1th target signal data to determine the kth DC signal data;

[0075] The receiver controller 2 is also used to return to the execution step of "eliminating the k-1th DC signal data from the kth target signal data to obtain the kth DC-eliminated target signal data" based on the k+1th target signal data and the kth DC signal data, until k is equal to (reaches) the total length of the target signal data.

[0076] In addition, the receiver DC removal system also includes registers and other components in the existing receiver except the above modules, such as conventional devices such as antennas, magnetic rods, diodes, triodes, and variable capacitors. Among them, the register is used to temporarily store the initial value of the DC signal and the process data in the calculation of the receiver controller 2 or the loop filter 3. The functions of other existing components in the receiver are not described in detail.

[0077] Example 3

[0078] This embodiment provides a practical application scenario of a receiver DC removal method, such as Figure 3 As shown, specifically including:

[0079] For a certain receiver, when it runs a universal mobile communication (LongTerm Evolution, LTE) system, the following steps are performed:

[0080] In the first step, when the receiver is turned on, it directly receives the target signal data with a set length of 16 and calculates its average value to obtain DC1:

[0081] DC1=(data(1)+…+data(16)) / 16.

[0082] In the second step, the target signal data with a set length of 64 is received and its average value is calculated to obtain DC2:

[0083] DC2=(data(1)+…+data(64)) / 64.

[0084] The third step is to calculate the sum DC3=DC1+DC2.

[0085] The fourth step is to use DC3 as the initial value of the DC signal, configure Dc_cal=DC3 through software and write it into the register. At the same time, the loop filter parameter K=12 needs to be configured.

[0086] The fifth step is to perform DC cancellation in the receiver controller, namely:

[0087] data_out(k)=data(k)-Dc_cal(k-1);

[0088] Among them, k=dataLen+1 and dataLen>16+64, and at the same time, Dc_cal(k-1)=Dc_cal=DC3 during the initial calculation.

[0089] Step 6: Figure 4 As shown, DC cancellation is performed inside the loop filter, namely:

[0090]

[0091] After executing step 6, set k+1 and return to step 5 to continue executing. Repeat steps 5 and 6 until all target signal data are received.

[0092] Step 7: When the receiver switches the communication system or the bandwidth of the communication system changes, the initial value of the DC signal has changed, so it is necessary to re-execute the process from the first step to the sixth step.

[0093] For a certain receiver, when it runs a 5G system, the following steps are performed:

[0094] In the first step, when the receiver is turned on, it directly receives the target signal data with a set length of 32 and calculates its average value to obtain DC1:

[0095] DC1=(data(1)+…+data(32)) / 32.

[0096] In the second step, the target signal data with a set length of 128 is received and its average value is calculated to obtain DC2:

[0097] DC2=(data(1)+…+data(128)) / 128.

[0098] The third step is to calculate the sum DC3=DC1+DC2.

[0099] The fourth step is to use DC3 as the initial value of the DC signal, configure Dc_cal=DC3 through software and write it into the register. At the same time, the loop filter parameter K=7 also needs to be configured.

[0100] The fifth step is to perform DC cancellation in the receiver controller, namely:

[0101] data_out(k)=data(k)-Dc_cal(k-1);

[0102] Among them, k=dataLen+1 and dataLen>32+128, and at the same time, Dc_cal(k-1)=Dc_cal=DC3 during the initial calculation.

[0103] Step 6: Figure 4 As shown, DC cancellation is performed inside the loop filter, namely:

[0104]

[0105] After executing step 6, set k+1 and return to step 5 to continue executing. Repeat steps 5 and 6 until all target signal data are received.

[0106] Step 7: When the receiver switches the communication system or the bandwidth of the communication system changes, the initial value of the DC signal has changed, so it is necessary to re-execute the process from the first step to the sixth step.

[0107] In summary, the present application builds a loop filter into the receiver, utilizes the loop filter to eliminate DC signals, and designs an initial value search operation for the DC signal, so that the receiver can quickly and stably eliminate DC signals.

[0108] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0109] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for removing direct current from a receiver, characterized in that: The receiver DC removal method comprises: Acquire target signal data; wherein the target signal data is mixed with DC signal data; Eliminating the k-1th DC signal data from the kth target signal data to obtain the kth target signal data after DC elimination; wherein the initial value of the DC signal data is determined according to the average value of n segments of target signal data of set length; n>1 and k>n+1; Perform loop filter operation on the kth and k-1th DC-eliminated target signal data, and the kth and k-1th target signal data to determine the kth DC signal data; wherein the calculation formula of the kth DC signal data is: Wherein, Dc_cal(k) is the kth DC signal data, K is the loop filter parameter, data_out(k) is the kth target signal data after DC elimination, and data(k) is the kth target signal data; Based on the k+1th target signal data and the kth DC signal data, return to the step of "eliminating the k-1th DC signal data from the kth target signal data to obtain the kth DC-eliminated target signal data" until k is equal to the total length of the target signal data.

2. The receiver DC removal method according to claim 1, characterized in that: The calculation formula of the kth target signal data after DC elimination is: data_out(k)=data(k)-Dc_cal(k-1); Wherein, data_out(k) is the k-th target signal data after DC elimination, data(k) is the k-th target signal data, and Dc_cal(k-1) is the k-1-th DC signal data.

3. The receiver DC removal method according to claim 1, characterized in that: The initial value of the DC signal data is determined according to the average value of the target signal data of n segments of set length, specifically including: Get n segments of target signal data of set length; Calculate the average value of target signal data of each set length respectively to obtain n target signal average values; The initial value of the DC signal is obtained by summing the average values ​​of the n target signals.

4. The receiver DC removal method according to claim 3, characterized in that: The calculation formula for the average value of the nth target signal is: DC n =(data(1)+…+data(dataLen n )) / dataLen n ; Where, DC n is the average value of the nth target signal, dataLen n is the nth set length, data(1) is the first data in the target signal data of the nth set length, data(dataLen n ) is the last data in the target signal data of the set length of the nth segment.

5. The receiver DC removal method according to claim 3, characterized in that: The calculation formula of the initial value of the DC signal is: Dc_cal=DC1+…+DC n ; Where Dc_cal is the initial value of the DC signal, DC1 is the average value of the first target signal, and DC n is the average value of the nth target signal.

6. The receiver DC removal method according to claim 1, characterized in that: The value of K is determined according to the bandwidth of the communication system; the bandwidth of the communication system is inversely proportional to the value of K.

7. The receiver DC removal method according to claim 1, characterized in that: The value of K is 7, 12, 16 or 20.

8. The receiver DC removal method according to claim 1, characterized in that: When the bandwidth of the communication system changes, the initial value of the DC signal also changes, and the receiver DC removal method needs to be re-executed.

9. A receiver DC removal system, characterized in that: The receiver DC removal system at least includes: an ADC sampling module, a receiver controller and a loop filter; The ADC sampling module is used to obtain target signal data; the target signal data is mixed with DC signal data; The receiver controller is connected to the ADC sampling module; the receiver controller is used to eliminate the k-1th DC signal data from the kth target signal data to obtain the kth DC-eliminated target signal data; wherein the initial value of the DC signal data is determined according to the average value of n segments of target signal data of set length; n>1 and k>n+1; The loop filter is connected to the receiver controller; the loop filter is used to perform loop filter operations on the kth and k-1th DC-eliminated target signal data, and the kth and k-1th target signal data to determine the kth DC signal data; wherein the calculation formula of the kth DC signal data is: Wherein, Dc_cal(k) is the kth DC signal data, K is the loop filter parameter, data_out(k) is the kth target signal data after DC elimination, and data(k) is the kth target signal data; The receiver controller is also used to return to the execution step of "eliminating the k-1th DC signal data from the kth target signal data to obtain the kth DC-eliminated target signal data" based on the k+1th target signal data and the kth DC signal data, until k is equal to the total length of the target signal data.

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