WO2011153760A1

WO2011153760A1 - Method and device for adjusting dynamic range of signal

Info

Publication number: WO2011153760A1
Application number: PCT/CN2010/077547
Authority: WO
Inventors: 王新宇; 张玉杰; 张健
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-06-09
Filing date: 2010-09-30
Publication date: 2011-12-15
Also published as: CN102281219B; CN102281219A

Abstract

A method and device for adjusting the dynamic range of signal are disclosed in the present invention. The method includes steps: calculating the module values of channel estimation values of data sub-carriers in the signal respectively (S202); calculating the average of the module values (S204); determining the shift number using the module values and the average value (S206); shifting the data of data sub-carriers by using the shift number, so that the dynamic range of signal is adjusted (S208). The present invention can improve the data accuracy and the system decoding performance.

Description

TECHNICAL FIELD The present invention relates to the field of communications, and in particular to a method and apparatus for adjusting a dynamic range of a signal. BACKGROUND OF THE INVENTION The existing Worldwide Interoperability for Microwave Access (WiMAX) wireless communication system based on the Institute for Electrical and Electronic Engineers (IEEE) 802.16e standard is positive. In the Orthogonal Frequency Division Multiplexing (OFDM) system, the dynamic range of the power value of each subcarrier at the transmitting end is usually small, but in the transmission process, the channel of each frequency point of the subcarrier is different. There is a difference between the power values of the respective subcarriers of the received signal. In the related art, the difference between the power values of the respective subcarriers is reduced by the channel estimation and the equalization operation. In theory, the WiMAX system performs channel estimation and equalization operations on the frequency domain data, multiplying the frequency domain data by the conjugate of the channel estimate, and dividing by the modulus square of the channel estimate, ie Α Η Η*/(|Η| ^Λ 2), where Α is the frequency domain data of the received subcarrier, and H is the channel estimation value, but when the actual hardware circuit is implemented, the division operation is not performed, but the corresponding steps after channel estimation equalization such as demodulation Procedure for the mesh ^Λ 2 corresponding compensation, however, channel estimation and equalization of the above-described embodiment, and can not achieve the effect of narrowing the dynamic range of the signal. Specifically, FIG. 1 is a flowchart of performing frequency domain equalization according to the related art. As shown in FIG. 1, the method includes the following steps: Step S102: The RRU radio unit receives data on the antenna; Step S104, receives the RRU. The obtained data is subjected to fast Fourier transform to the frequency domain; step S106, the frequency domain data is subjected to a high-displacement operation; and step S108, the shifted data is subjected to time-frequency offset calculation; In step S110, channel estimation and equalization are performed, and the frequency domain data is multiplied by the conjugate of the channel estimation value, that is, A x H* , where A is the frequency domain data of the received subcarrier. If H is too large or too small, the frequency domain data of its subcarrier is too large or too small. If H is large, the power value of the frequency domain data of the corresponding subcarrier is also large, then the power of A x H* is larger. On the other hand, if H is small, indicating that the power value of the frequency domain data of the corresponding subcarrier is also small, then the power of A x H* is smaller; and in step S112, the channel estimation and the equalized data are equally gain-combined. Step S114, performing signal demodulation, compensating for the division operation not performed by the channel estimation, dividing the signal by |Η| ^Λ 2. It can be seen from the above process that in the actual channel, due to the channel difference, that is, the channel attenuation of each subcarrier is different, as in step S110, the channel estimation value Η is relatively large, and only after channel estimation and equalization is |Η ^Λ 2 performs compensation (compensation in step S 114 after step S 110), so that the values of AxH* obtained by each subcarrier in channel estimation and equalization are largely different, and in actual systems, subcarriers are saved. In a certain number of bits, the subcarrier effective bits causing the smaller power are present in the lower bits, and the effective bits of the higher power subcarriers are stored in the higher bits, ie, the signal The subcarrier power has a problem that the dynamic range is too large. Thus, the channel estimation and equalization operations can not only reduce the dynamic range of the signal, but also expand the original signal dynamic range, and the accuracy of the data is relatively low. When channel estimation and equalization operations are performed in the related art, the signal dynamic range of the data subcarrier is relatively low due to the relatively large dynamic range of the signal, which in turn leads to poor decoding performance of the entire system. SUMMARY OF THE INVENTION A primary object of the present invention is to provide a method and apparatus for adjusting a dynamic range of a signal, so as to solve the above-mentioned channel estimation and equalization operation, since the dynamic range of the signal is relatively large, the accuracy of the data subcarrier data is relatively low. , which in turn leads to a problem of poor decoding performance of the entire system. In order to achieve the above object, according to an aspect of the invention, a method of adjusting a dynamic range of a signal is provided. A method for adjusting a dynamic range of a signal according to the present invention includes: separately calculating a modulus value of a channel estimation value of a data subcarrier in a signal; calculating an average value of the modulus values; determining a displacement number using a modulus value and an average value; The carrier data is shifted to adjust the dynamic range of the signal. Further, determining the displacement number by using the modulus value and the average value includes: calculating a ratio of the modulus value to the average value; if the ratio is greater than the first threshold value or less than the second threshold value, the modulus value is displaced to determine the mode after the displacement The displacement amount when the absolute value of the difference between the value and the average value is the smallest is the displacement number. Further, the first threshold value and the second threshold value are determined according to the average value and the modulus value. Further, using the displacement number to shift the data of the data subcarrier includes: using the half of the displacement as the displacement amount to perform the first displacement operation on the data subcarrier data; performing channel estimation and equalization operation; using half of the displacement number as The amount of displacement performs a second shift operation on the data subcarrier data. Further, after performing the second shift operation on the data subcarrier data by using half of the displacement number as the displacement amount, the method further includes: compensating data of the shifted data subcarrier. Further, the modulus values of the channel estimation values of the data subcarriers are respectively calculated by channel estimation values of the pilot subcarriers in the signal. In order to achieve the above object, according to another aspect of the present invention, an apparatus for adjusting a dynamic range of a signal is provided. The apparatus for adjusting the dynamic range of a signal according to the present invention comprises: a modulus value calculation module for respectively calculating a modulus value of a channel estimation value of a data subcarrier in a signal; an average value calculation module for calculating an average value of the modulus value; , used to determine the displacement number using the modulus and the average value; the displacement module is configured to use the displacement number to shift the data subcarrier data to adjust the dynamic range of the signal. Further, the determining module includes: a ratio calculating module, configured to calculate a ratio of the modulus value and the average value; and a displacement determining module, configured to: if the ratio is greater than the first threshold value or less than the second threshold value, to shift the modulus value, The absolute value of the difference between the modulus value after the displacement and the average value is determined to be the most 'j, and the displacement amount at the time is the displacement number. Further, the displacement module comprises: a first displacement module for performing a displacement operation using half of the displacement number as a displacement amount; a channel estimation and equalization module for performing channel estimation and equalization operation; and a second displacement module for using the displacement Half of the number is used as a displacement to perform a shift operation on the data subcarrier data. Further, the foregoing apparatus further includes: a compensation module, configured to compensate data of the shifted data subcarrier after performing a second displacement operation on the data subcarrier data by using half of the displacement number as the displacement amount. By means of the invention, the modulus values of the channel estimation values of the data subcarriers in the signal are separately calculated; the average value of the modulus values is calculated; the displacement values are determined using the modulus values and the average values; and the data subcarrier data is shifted using the number of displacements, It is used to adjust the dynamic range of the signal, and solves the problem that when the channel estimation and the equalization operation are performed, the signal dynamic range of the data subcarrier is relatively low due to the relatively large dynamic range of the signal, which in turn leads to the problem that the decoding performance of the whole system is relatively poor. Improve the accuracy of data and system decoding performance. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawings: FIG. 1 is a flow chart for performing frequency domain equalization according to the related art; FIG. 2 is a flow chart of a method for adjusting a dynamic range of a signal according to an embodiment of the present invention; FIG. 3 is a preferred embodiment of the present invention. FIG. 4 is a flowchart of a method for adjusting a dynamic range of a signal according to an embodiment of the present invention; FIG. 5 is a structural block diagram of an apparatus for adjusting a dynamic range of a signal according to an embodiment of the present invention; Fig. 6 is a block diagram showing a preferred configuration of an apparatus for adjusting a dynamic range of a signal according to an embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. According to an embodiment of the present invention, a method for adjusting a dynamic range of a signal is provided. FIG. 2 is a flowchart of a method for adjusting a dynamic range of a signal according to an embodiment of the present invention. As shown in FIG. 2, the method includes: Step S202: Calculating separately a modulus value of the channel estimation value of the data subcarrier in the signal; Step S204, calculating an average value of the modulus values; Step S206, determining the displacement number using the modulus value and the average value; Step S208: The data of the data subcarrier is shifted by using the number of displacements to adjust the dynamic range of the signal. In the related art, when the channel estimation and the equalization operation are performed, since the dynamic range of the signal is relatively large, the accuracy of the data of the data subcarrier is relatively low, which in turn leads to poor decoding performance of the entire system. In the embodiment of the present invention, the modulus value of the channel estimation value of the data subcarrier in the signal is separately calculated; the average value of the modulus value is calculated; the displacement value is determined by using the modulus value and the average value; and the data subcarrier data is performed by using the displacement number. The displacement is used to adjust the dynamic range of the signal, and solves the problem that when the channel estimation and the equalization operation are performed, the data dynamic range of the data subcarrier is relatively low due to the relatively large dynamic range of the signal, and the decoding performance of the entire system is relatively poor. In turn, the effect of improving data accuracy and system decoding performance is achieved. Preferably, step S206 includes: calculating a ratio of the modulus value to the average value; if the ratio is greater than the first threshold value or less than the second threshold value, shifting the modulus value to determine a difference between the modulus value after the displacement and the average value The absolute value of the most 'j, the amount of displacement is the number of displacements. Preferably, the first threshold value and the second threshold value are determined based on the average value and the modulus value. Preferably, step S208 includes: performing a first shift operation on the data subcarrier data by using half of the displacement number as the displacement amount; performing channel estimation and equalization operation; using the half of the displacement number as the displacement amount to perform data subcarrier data The second displacement operation. With the preferred embodiment, before the channel estimation and equalization operations, the displacement is shifted by half, the dynamic range is first reduced, and after the channel estimation and equalization operations, the displacement is shifted by the remaining displacement, and the two steps make the dynamics of the channel. The range has been effectively reduced. Preferably, after the second displacement operation is performed on the data subcarrier data by using half of the displacement number as the displacement amount, the method further includes: compensating data of the shifted data subcarrier. Through the preferred embodiment, the data of the shifted data subcarriers is compensated, so that the shifted data is maintained in the original order of magnitude, and the precision of data processing is improved. Preferably, the modulus values of the channel estimation values of the data subcarriers are respectively calculated by channel estimation values of the pilot subcarriers in the signal. With the preferred embodiment, the pilot subcarrier estimate in the signal is used to calculate the modulus of the channel estimate for the data subcarrier, reducing the amount of computation. First Embodiment FIG. 3 is a flowchart of performing frequency domain equalization according to a preferred embodiment of the present invention, as shown in FIG. include:

Step S302, the remote radio unit (Radio Remote Unit, RRU for short) radio frequency unit receives data on the antenna; step S304, performing fast Fourier transform on the data received by the RRU to the frequency domain; step S306, to reduce the dynamic range Performing the first shifting; step S308, performing the shifting data to the high shift operation; step S310, performing the time-frequency offset calculation on the shifted data; and step S312, performing channel estimation and equalization, and applying the same Multiplying the frequency domain data by the conjugate of the channel estimation value, that is, A x H* , where A is the frequency domain data of the received subcarrier; step S314, performing the second shift for reducing the dynamic range; Step S316, The shifted data is subjected to equal gain combining; in step S318, signal demodulation is performed, and at the same time, the division operation and the displacement operation which are not performed by the channel estimation are compensated, and the actual compensation is the number of net shifts of the network and AXH*. This embodiment performs the first shift before channel estimation and equalization and the second shift after channel estimation and equalization, and shifts the whole of |Η| ^Λ 2 and AXH* after the second shift. The number is compensated, which reduces the dynamic range of the signal and improves the accuracy of the data. The second embodiment of the present invention further provides a preferred embodiment, combining the technical solutions of the above multiple preferred embodiments, and FIG. 4 is a preferred flowchart of a method for adjusting the dynamic range of a signal according to an embodiment of the present invention, which is combined below. Figure 4 is described in detail. Step S402, determining a channel estimation value of the data subcarrier according to the pilot subcarrier. Step S404, finding a modulus of the value of each data subcarrier equalized, that is, |A x H*|. Step S406: Find an average value of the value modules after all data subcarriers are equalized. Step S408, calculating, for each data subcarrier, a ratio of a modulus value of the Α X Η* to an average value. If the value is greater than the predetermined value a or less than the predetermined value b, the modulus value of the AXH* is shifted to the nearest value. The average value is simultaneously recorded as the shift number scale, where a and 1 are calculated based on the average value and the modulus value. Step S410, for all data subcarriers, the first shift is performed on the scale value thereof, and the number of shifts is scale/2. It should be noted that step S402 to step S410 are detailed steps of step S306 in FIG. 3 for performing the first shift in order to reduce the dynamic range. Step S412, for the channel estimation and the equalized data subcarrier, the second shift is performed according to the scale value thereof. It should be noted that if the scale is even, the number of displacements before and after is both scale/2. If the scale is odd, the first displacement is scale/2, and the second displacement is (scale+l)/2. . Step S412 corresponds to step S314 in FIG. 3 for the second shift in order to reduce the dynamic range. Step S414, when compensating for channel division and equalization without equalization, the actual compensation is (|H| ^A 2) * scale. It should be noted that step S414 performs signal demodulation corresponding to step S318 in FIG. 3, and compensates for the division operation and the displacement operation that are not performed by the channel estimation, and the actual compensation is the total shift of |Η| ^Λ 2 and AXH*. number. With the embodiment of the present invention, the first shift is performed with a scale/2 as a displacement amount before the channel estimation and equalization, and the second shift is performed with (scale+l)/2 after the channel estimation and equalization, and |H| 2 and AXH* compensate for the number of overall shifts, reducing the dynamic range of the signal and improving data accuracy. It should be noted that the steps shown in the flowchart of the accompanying drawings may be performed in a computer system such as a set of computer executable instructions, and, although the logical order is shown in the flowchart, in some cases, The steps shown or described may be performed in an order different than that herein. According to an embodiment of the present invention, an apparatus for adjusting a dynamic range of a channel is provided. FIG. 5 is a structural block diagram of an apparatus for adjusting a dynamic range of a signal according to an embodiment of the present invention. As shown in FIG. 5, the apparatus includes: modulus calculation. The module 52, the average value calculation module 54, the determination module 56 and the displacement module 58 are described in detail below: The modulus calculation module 52 is configured to separately calculate a modulus value of the channel estimation value of the data subcarrier in the signal; the average value calculation module 54 is connected to the modulus value calculation module 52, and is configured to calculate the modulus value calculated by the modulus calculation module 52. The average value of the determination module 56 is connected to the modulus calculation module 52 and the average value calculation module 54 for determining the displacement number using the modulus calculated by the modulus calculation module 52 and the average value calculated by the average calculation module 54. The displacement module 58 is coupled to the determination module 56 for displacing the data subcarrier data using the number of displacements determined by the determination module 56 for adjusting the signal dynamic range. In the related art, when the channel estimation and the equalization operation are performed, the data dynamic range of the data subcarrier is relatively low due to the relatively large dynamic range of the signal, and the decoding performance of the entire system is relatively poor. In the embodiment of the present invention, the modulus value of the channel estimation value of the data subcarrier in the signal is separately calculated and the average value of the modulus value is calculated; the displacement is determined by using the modulus value and the average value to adjust the dynamic range of the signal, and the solution is used to adjust the dynamic range of the signal. When the channel estimation and equalization operations are performed, due to the relatively large dynamic range of the signal, the accuracy of the data subcarrier data is relatively low, and even the decoding performance of the whole system is relatively poor, thereby improving the data precision and system decoding. Performance effect. 6 is a block diagram of a preferred structure of an apparatus for adjusting a dynamic range of a signal according to an embodiment of the present invention. As shown in FIG. 6, the determining module 56 includes: a ratio calculating module 562 and a displacement determining module 564. The displacement module 58 includes: a first displacement The module 582, the channel estimation and equalization module 584 and the second displacement module 586, the apparatus further includes a compensation module 62. The above structure is described in detail below. The determining module 56 includes: a ratio calculating module 562 connected to the modulus calculating module 52. And an average value calculation module 54 for calculating a ratio of the modulus value calculated by the modulus calculation module 52 and the average value calculated by the average value calculation module 54; the displacement determination module 564 is connected to the ratio calculation module 562 for calculating The calculated ratio of the module 562 is greater than the first threshold value or less than the second threshold value, and the modulus value is displaced, and the displacement amount when the absolute value of the difference between the modulus value and the average value after the displacement is determined to be the smallest is the displacement number. The displacement module 58 includes: a first displacement module 582 connected to the displacement determining module 564 for performing a second displacement operation on the data subcarrier data by using half of the displacement number determined by the displacement determining module 564 as a displacement amount; The equalization module 584 is connected to the first displacement module 582 for channel estimation and equalization operation on the data after the displacement of the first displacement module 582. The second displacement module 586 is connected to the displacement determination module 564 for using the displacement determination module. A half of the number of displacements determined by 564 is used as a displacement amount to perform a second displacement operation on the data subcarrier data. The device further includes: a compensation module 62 connected to the second displacement module 586 for pairing the second The displacement module 586 compensates the data subcarrier data after the data subcarrier data is shifted by using half of the displacement number as the displacement amount. With the preferred embodiment, before the channel estimation and equalization operations, the displacement is shifted by half, the dynamic range is reduced for the first time, and after the channel estimation and equalization operations, the displacement is shifted by the remaining displacement, and the two steps make the dynamics of the channel. The range has been effectively reduced. It should be noted that the apparatus for adjusting the dynamic range of the signal described in the foregoing embodiment corresponds to the foregoing method embodiment, and the specific implementation process has been described in detail in the method embodiment, and details are not described herein again. In summary, the present invention solves the problem that when the channel estimation and the equalization operation are performed, the signal dynamic range of the data subcarrier is relatively low due to the relatively large dynamic range of the signal, and the decoding performance of the entire system is relatively poor. And improve data accuracy and system decoding performance. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. The steps shown or described are performed, or they are separately fabricated into individual integrated circuit modules, or a plurality of modules or steps are fabricated as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

A method for adjusting a dynamic range of a signal, comprising:

Calculating a modulus value of a channel estimation value of the data subcarrier in the signal, respectively;

Calculating an average value of the modulus values;

Determining the number of displacements using the modulus value and the average value;

The data of the data subcarrier is shifted using the number of displacements to adjust the dynamic range of the signal.

2. The method according to claim 1, wherein determining the displacement number using the modulus value and the average value comprises:

Calculating a ratio of the modulus value to the average value;

If the ratio is greater than the first threshold or less than the second threshold, the modulus is displaced to determine the absolute value of the difference between the modulus and the average after the displacement is minimum The amount of displacement is the number of displacements.

3. The method according to claim 2, wherein the first threshold value and the second threshold value are determined according to the average value and the modulus value.

4. The method of claim 1, wherein the shifting the data of the data subcarriers using the number of displacements comprises:

Performing the first displacement operation on the data of the data subcarrier using half of the displacement number as a displacement amount;

Perform channel estimation and equalization operations;

The data of the data subcarrier is subjected to the second displacement operation using half of the displacement number as the displacement amount.

The method according to claim 4, after the second performing the shifting operation on the data of the data subcarrier by using one half of the displacement number as a displacement amount, further comprising: The data of the data subcarrier after the displacement is compensated.

6. The method according to claim 1, wherein a modulus value of a channel estimation value of the data subcarrier is separately calculated by a channel estimation value of a pilot subcarrier in the signal.

7. A device for adjusting a dynamic range of a signal, comprising:

a modulus calculation module, configured to separately calculate a modulus of a channel estimation value of the data subcarrier in the signal;

An average value calculation module, configured to calculate an average value of the modulus values;

a determining module, configured to determine a displacement number by using the modulus value and the average value; and a displacement module configured to use the displacement number to shift data of the data subcarrier to adjust the dynamic range of the signal.

The device according to claim 7, wherein the determining module comprises:

a ratio calculation module, configured to calculate a ratio of the modulus value to the average value; a displacement determining module, configured to shift the modulus value if the ratio is greater than a first threshold value or less than a second threshold value And determining, when the absolute value of the difference between the modulus value and the average value after the displacement is the smallest, the displacement amount is the displacement number.

9. The device according to claim 7, wherein the displacement module comprises:

a first displacement module, configured to perform the shift operation using one half of the displacement number as a displacement amount;

a channel estimation and equalization module, configured to perform channel estimation and equalization operations; and a second displacement module, configured to perform the shifting operation on data of the data subcarriers by using one half of the displacement number as a displacement amount.

10. The apparatus according to claim 9, further comprising: a compensation module, configured to perform a second shift operation on data of the data subcarrier using half of the displacement number as a displacement amount Thereafter, the data of the shifted data subcarriers is compensated.