CN103873412B - For carrying out the method and apparatus of frequency domain average treatment to the DMRS symbols in OFDM symbol - Google Patents
For carrying out the method and apparatus of frequency domain average treatment to the DMRS symbols in OFDM symbol Download PDFInfo
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Abstract
It is an object of the invention to provide a kind of method and apparatus for being used to carry out the DMRS symbols in OFDM symbol frequency domain average treatment.Frequency domain sequence of the compensation device corresponding to by the acquisition partial compensation for the time information corresponding with the DMRS symbols corresponding to OFDM symbol and the DMRS symbols, and according to the partial compensation for the time information, partial compensation for the time processing is carried out to the frequency domain sequence, then the frequency domain sequence handled through partial compensation for the time is averaging processing, to obtain the frequency domain average result corresponding to the DMRS symbols.Compared with prior art, the present invention with the frequency domain sequence of the certain length corresponding to the DMRS symbols by pair carrying out average method after first compensation, realize the partial compensation for the time to up channel, reduce the amount of calculation needed for compensation, and reduce the amount of storage needed for the storage partial compensation for the time information, it is achieved thereby that partial compensation for the time.
Description
Technical Field
The present invention relates to the field of wireless communications, and in particular, to a technique for performing frequency domain averaging processing on DMRS symbols in OFDM symbols.
Background
The LTE system utilizes a Cyclic Prefix (CP) to avoid Inter-Symbol Interference (ISI) caused by multipath. In order to keep most of the multipath components within the range of the cyclic prefix, the center of gravity of the wireless channel multipath components is mostly near the center of the cyclic prefix, and therefore, there is a non-zero time offset on the signals received by the evolved nodeb (eNodeB). The presence of time offsets will result in inaccuracies in the channel estimates as well as in measurements such as noise estimation, velocity estimation, etc. Therefore, in order to improve the performance of the eNodeB, time offset compensation is required in the uplink reception link.
Since the time offset in the time domain corresponds to the linear phase rotation in the frequency domain, one solution for time offset compensation is the linear phase derotation in the frequency domain.
Although linear phase derotation in the frequency domain is a simple and effective solution, it still has 2 disadvantages:
first, phase De-rotation should be performed in each Orthogonal Frequency Division Multiplexing (OFDM) symbol including 12 data symbols and 2 Reference Signal symbols (DMRS symbols) for demodulation, and each OFDM symbol has N Physical Resource Block numbers (PRBs) in the LTE systemSub-carriers, so this scheme requires in every sub-frame/Transmission Time Interval (TTI)/1 msThe next complex multiplication. For example, in a 20MHZ LTE system, this scheme requires 16800 complex multiplications per second, which is a little more computationally expensive. Wherein,in the LTE system, the number of Resource Blocks (RBs) included in an uplink OFDM symbol,is the number of Subcarriers (SC) included in each resource block,which is the number of subcarriers used in the uplink OFDM symbol.
Second, linear phase inversion requires a compensation coefficient table to be generated for each system Bandwidth (BW) and time offset, i.e.Wherein,since the sin and cos functions need to be used multiple times, the amount of computation is large. If tauTAThe implementation pressure for DSP or FPGA is very large.
Disclosure of Invention
The invention aims to provide a method and equipment for carrying out frequency domain average processing on DMRS symbols in OFDM symbols.
According to an aspect of the present invention, there is provided a method for performing frequency domain averaging processing on DMRS symbols in an OFDM symbol, wherein the method comprises the steps of:
a, acquiring time offset compensation information corresponding to a DMRS symbol corresponding to an OFDM symbol;
wherein, the method also comprises:
b, acquiring a frequency domain sequence corresponding to the DMRS symbol;
c, performing time offset compensation processing on the frequency domain sequence according to the time offset compensation information;
d, averaging the frequency domain sequence subjected to the time offset compensation processing to obtain a frequency domain average result corresponding to the DMRS symbol.
According to another aspect of the present invention, there is also provided a compensation apparatus for performing frequency domain averaging processing on a DMRS symbol in an OFDM symbol, wherein the apparatus includes:
a compensation obtaining unit, configured to obtain time offset compensation information corresponding to a DMRS symbol corresponding to an OFDM symbol;
wherein, the method also comprises:
a sequence acquisition unit, configured to acquire a frequency domain sequence corresponding to the DMRS symbol;
the compensation unit is used for carrying out time offset compensation processing on the frequency domain sequence according to the time offset compensation information;
and an averaging unit, configured to perform averaging processing on the frequency domain sequence subjected to the time offset compensation processing to obtain a frequency domain averaging result corresponding to the DMRS symbol.
According to still another aspect of the present invention, there is also provided a receiving apparatus for performing frequency domain averaging processing on DMRS symbols in OFDM symbols passing through an uplink channel, including the compensation device as described above.
Compared with the prior art, the method comprises the steps of obtaining time offset compensation information corresponding to a DMRS symbol corresponding to an OFDM symbol and a frequency domain sequence corresponding to the DMRS symbol, carrying out time offset compensation processing on the frequency domain sequence according to the time offset compensation information, and then carrying out average processing on the frequency domain sequence subjected to the time offset compensation processing to obtain a frequency domain average result corresponding to the DMRS symbol; therefore, by means of the method of performing compensation first and then averaging on the frequency domain sequence with a certain length corresponding to the DMRS symbol, time offset compensation of an uplink channel is achieved, the calculation amount required by compensation is reduced, the storage amount required by storing the time offset compensation information is reduced, and therefore time offset compensation is achieved. In addition, the invention can also determine the time offset compensation information corresponding to the DMRS symbol according to the frequency domain average window corresponding to the DMRS symbol, so as to perform time offset compensation processing on each item of the frequency domain sequence according to the frequency domain average window; therefore, the time offset compensation can be realized by using the time offset compensation information which has the length corresponding to the frequency domain average window and corresponds to the DMRS symbol, and the storage amount required for storing the time offset compensation information is reduced. Furthermore, the invention can further reduce the storage amount required for storing the time offset compensation information according to the property of the time offset compensation information. Moreover, the invention can also carry out weighted average on the frequency domain sequence after time offset compensation processing according to the weight sequence corresponding to the frequency domain sequence corresponding to the DMRS symbol so as to obtain the frequency domain average result corresponding to the DMRS symbol; therefore, different weights can be defined according to different reliabilities of different symbols in the frequency domain sequence, and the like, so that a frequency domain average result which is more in line with the requirement is obtained.
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Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments made with reference to the following drawings:
fig. 1 shows a schematic diagram of a compensation apparatus for frequency domain averaging DMRS symbols in an OFDM symbol according to an aspect of the present invention;
fig. 2 shows a flow diagram of a method for frequency domain averaging DMRS symbols in an OFDM symbol, according to another aspect of the invention;
fig. 3 shows a schematic diagram, preferably for frequency domain averaging processing of DMRS symbols in an OFDM symbol, according to an aspect of the present invention;
fig. 4 to 6 show simulation effect graphs under different channels and different simulation conditions.
The same or similar reference numbers in the drawings identify the same or similar elements.
Detailed Description
The present invention is described in further detail below with reference to the attached drawing figures.
Fig. 1 shows a schematic diagram of a compensation apparatus for frequency domain averaging DMRS symbols in an OFDM symbol according to an aspect of the present invention; the compensation device comprises a compensation acquisition unit 11, a sequence acquisition unit 12, a compensation unit 13 and an averaging unit 14. Specifically, the compensation obtaining unit 11 obtains time offset compensation information corresponding to a DMRS symbol corresponding to an OFDM symbol; the sequence acquiring unit 12 acquires a frequency domain sequence corresponding to the DMRS symbol; the compensation unit 13 performs time offset compensation processing on the frequency domain sequence according to the time offset compensation information; the averaging unit 14 performs averaging processing on the frequency domain sequence subjected to the time offset compensation processing to obtain a frequency domain averaging result corresponding to the DMRS symbol. The compensation device includes, but is not limited to, any computing device or computing unit capable of performing frequency domain averaging processing on DMRS symbols in the OFDM symbols.
The above-mentioned units continuously operate, and herein, those skilled in the art should understand that "continuously" means that the above-mentioned units respectively perform, in real time or according to the set or real-time adjusted operating mode requirement, the acquisition of the time offset compensation information, the acquisition of the frequency domain sequence, the time offset compensation processing of the frequency domain sequence, the average processing of the frequency domain sequence after the time offset compensation processing, and the like until the compensation apparatus stops acquiring the time offset compensation information corresponding to the DMRS symbol corresponding to the OFDM symbol.
The compensation acquisition unit 11 acquires time offset compensation information corresponding to a DMRS symbol corresponding to an OFDM symbol. Specifically, the compensation obtaining unit 11 interacts with a database storing time offset compensation information, or a corresponding device storing time offset compensation information, or calculates time offset compensation information corresponding to a DMRS symbol corresponding to an OFDM symbol according to a related calculation parameter of the time offset compensation information. Wherein the corresponding time offset compensation information comprises one or more numerical values corresponding to the DMRS symbols, and the like.
The sequence acquiring unit 12 acquires a frequency domain sequence corresponding to the DMRS symbol. Specifically, the sequence obtaining unit 12 obtains the frequency domain sequence by interacting with a database or other corresponding devices storing the frequency domain sequence corresponding to the DMRS symbol; or converting the time domain information of the signal into frequency domain information through time-frequency conversion by using time-frequency conversion, thereby obtaining the frequency domain sequence corresponding to the DMRS symbol. Here, the sequence includes one or more frequency-domain values that are contiguous in a time domain corresponding to the DMRS symbol.
The compensation unit 13 performs time offset compensation processing on the frequency domain sequence according to the time offset compensation information. Specifically, the compensation unit 13 performs time offset compensation processing on the frequency domain sequence by calculating the time offset compensation information and the frequency domain sequence according to the time offset compensation information. Wherein the calculating includes, but is not limited to, calculating the time offset compensation information corresponding to the frequency domain sequence.
The averaging unit 14 performs averaging processing on the frequency domain sequence subjected to the time offset compensation processing to obtain a frequency domain averaging result corresponding to the DMRS symbol. Specifically, the averaging unit 14 obtains a frequency domain averaging result corresponding to the DMRS symbol by averaging the frequency domain sequence compensated by the compensation unit 13, for example, by adding and averaging.
Preferably, the averaging unit 14 may further obtain a weight sequence corresponding to a frequency domain sequence corresponding to the DMRS symbol; and carrying out weighted average on the frequency domain sequence subjected to time offset compensation according to the weight sequence corresponding to the frequency domain sequence corresponding to the DMRS symbol so as to obtain a frequency domain average result corresponding to the DMRS symbol. Specifically, the averaging unit 14 may determine, through system preset or according to related information of a corresponding channel, a weight sequence corresponding to a frequency domain sequence corresponding to the DMRS symbol; or interacting with a correlation device, such as a database, storing the weight sequence to obtain the weight sequence corresponding to the frequency domain sequence corresponding to the DMRS symbol, where the weight sequence may be the same value or a plurality of different values and corresponds to the frequency domain sequence corresponding to the DMRS symbol in a one-to-one manner. The averaging unit 14 weights and averages the weight sequences and the frequency domain sequences according to the weight sequences to obtain a frequency domain averaging result corresponding to the DMRS symbol. Therefore, different weights (such as different weights according to the corresponding reliability, etc.) can be defined according to symbols with different time offset information (i.e. different positions in the frequency domain sequence) to obtain a more desirable result.
Preferably, the compensation obtaining unit 11 may further determine time offset compensation information corresponding to the DMRS symbol according to a frequency domain average window corresponding to the DMRS symbol; the compensation unit 13 may further perform time offset compensation processing on each item of the frequency domain sequence in the frequency domain averaging window according to the time offset compensation information. Specifically, the compensation obtaining unit 11 may obtain or determine a frequency domain average window corresponding to the DMRS symbol through system preset or according to a relevant condition of a corresponding signal, where the frequency domain average window has a fixed length (e.g., 2K +1, K is a positive integer value), so as to determine 2K +1 pieces of time offset compensation information corresponding to the DMRS symbol according to the frequency domain average window; the compensation unit 13 may further perform time offset compensation processing on each item of the frequency domain sequence in the frequency domain averaging window according to the 2K +1 time offset compensation information, that is, perform time offset compensation processing on adjacent 2K +1 frequency domain values in the frequency domain sequence, and perform the time offset compensation processing sequentially, thereby obtaining the frequency domain sequence subjected to the time offset compensation processing.
More preferably, the compensation obtaining unit 11 may further determine, according to the frequency domain average window corresponding to the DMRS symbol, the time offset compensation information p (i) corresponding to the DMRS symbol based on the following formula:
(formula 1)
Wherein K is the length of one side of the frequency domain averaging window, NFFTLength information of frequency domain sequence for the DMRS, tauTAIs a time offset value predetermined or estimated in advance. When tau isTAWhen limited to a fixed value, the required compensation factors can be stored in the table in advance, thereby reducing the amount of computation, but different compensation factors need to be stored for different bandwidths. More preferably, the value of K must satisfy the design of LTE systemUnder a fading channel, the value of K is generally less than or equal to 2; k is less than or equal to 2, the amount of memory consumed can be substantially reduced.
More preferably, the time offset compensation information includes p (i), i ═ 1, 2. Wherein,
p (-i) ═ real (P (i)) -j × imag (P (i)) (formula 1)
Therefore, the P (-i) can be determined according to the P (i), and P (0) is 1, so that the value of the P (i) is only required to be stored, and the storage space is reduced by half.
Fig. 2 shows a flow diagram of a method for frequency domain averaging DMRS symbols in an OFDM symbol, according to another aspect of the invention. Specifically, in step s1, the compensation apparatus acquires time offset compensation information corresponding to a DMRS symbol corresponding to an OFDM symbol; in step s2, the compensation apparatus acquires a frequency domain sequence corresponding to the DMRS symbol; in step s3, the compensation device performs time offset compensation processing on the frequency domain sequence according to the time offset compensation information; in step s4, the compensation device performs an averaging process on the frequency domain sequence subjected to the time offset compensation process to obtain a frequency domain averaging result corresponding to the DMRS symbol.
The above steps are continuously operated, and herein, those skilled in the art should understand that "continuously" means that the above steps are respectively performed in real time, or according to the set or real-time adjusted operating mode requirement, until the compensation device stops acquiring the time offset compensation information corresponding to the DMRS symbol corresponding to the OFDM symbol, such as acquiring the time offset compensation information, acquiring the frequency domain sequence, performing the time offset compensation processing on the frequency domain sequence, and performing the average processing on the frequency domain sequence subjected to the time offset compensation processing.
In step s1, the compensation device acquires time offset compensation information corresponding to the DMRS symbol corresponding to the OFDM symbol. Specifically, in step s1, the compensation device calculates the time offset compensation information corresponding to the DMRS symbol corresponding to the OFDM symbol by interacting with a database storing the time offset compensation information, or a corresponding device storing the time offset compensation information, or according to a related calculation parameter of the time offset compensation information. Wherein the corresponding time offset compensation information comprises one or more numerical values corresponding to the DMRS symbols, and the like.
In step s2, the compensation apparatus acquires a frequency domain sequence corresponding to the DMRS symbol. Specifically, in step s2, the compensation apparatus interacts with a database or other corresponding apparatus storing the frequency domain sequence corresponding to the DMRS symbol to obtain the frequency domain sequence; or converting the time domain information of the signal into frequency domain information through time-frequency conversion by using time-frequency conversion, thereby obtaining the frequency domain sequence corresponding to the DMRS symbol. Here, the sequence includes one or more frequency-domain values that are contiguous in a time domain corresponding to the DMRS symbol.
In step s3, the compensation device performs time offset compensation processing on the frequency domain sequence according to the time offset compensation information. Specifically, in step s3, the compensation device performs time offset compensation processing on the frequency domain sequence by calculating the time offset compensation information and the frequency domain sequence according to the time offset compensation information. Wherein the calculating includes, but is not limited to, calculating the time offset compensation information corresponding to the frequency domain sequence.
In step s4, the compensation device performs an averaging process on the frequency domain sequence subjected to the time offset compensation process to obtain a frequency domain averaging result corresponding to the DMRS symbol. Specifically, in step s4, the compensation device obtains a frequency domain averaging result corresponding to the DMRS symbol by averaging the frequency domain sequence subjected to the compensation process in step s3, for example, by adding and averaging the frequency domain sequence.
Preferably, in step s4, the compensation apparatus may further obtain a weight sequence corresponding to the frequency domain sequence corresponding to the DMRS symbol; and carrying out weighted average on the frequency domain sequence subjected to time offset compensation according to the weight sequence corresponding to the frequency domain sequence corresponding to the DMRS symbol so as to obtain a frequency domain average result corresponding to the DMRS symbol. Specifically, in step s4, the compensation apparatus may determine, by system preset or according to the relevant information of the corresponding channel, the weight sequence corresponding to the frequency domain sequence corresponding to the DMRS symbol; or interacting with a correlation device, such as a database, storing the weight sequence to obtain the weight sequence corresponding to the frequency domain sequence corresponding to the DMRS symbol, where the weight sequence may be the same value or a plurality of different values and corresponds to the frequency domain sequence corresponding to the DMRS symbol in a one-to-one manner. In step s4, the compensation device weights and averages the weight sequence and the frequency domain sequence according to the weight sequence to obtain a frequency domain averaging result corresponding to the DMRS symbol. Therefore, different weights (such as different weights according to the corresponding reliability, etc.) can be defined according to symbols with different time offset information (i.e. different positions in the frequency domain sequence) to obtain a more desirable result.
Preferably, in step s1, the compensation apparatus may further determine, according to the frequency domain average window corresponding to the DMRS symbol, time offset compensation information corresponding to the DMRS symbol; in step s3, the compensation device may further perform time offset compensation processing on each item of the frequency domain sequence in the frequency domain averaging window according to the time offset compensation information. Specifically, in step s1, the compensation apparatus may obtain or determine, through system preset or according to a correlation condition of a corresponding signal, a frequency domain average window corresponding to the DMRS symbol, where the frequency domain average window is, for example, a fixed length (e.g., 2K +1, K is a positive integer value), so as to determine, according to the frequency domain average window, 2K +1 pieces of time offset compensation information corresponding to the DMRS symbol; in step s3, the compensation apparatus may further perform time offset compensation processing on each item of the frequency domain sequence in the frequency domain average window according to the 2K +1 time offset compensation information, that is, perform time offset compensation processing on adjacent 2K +1 frequency domain values in the frequency domain sequence, and perform the time offset compensation processing sequentially, thereby obtaining the frequency domain sequence subjected to the time offset compensation processing.
More preferably, in step s1, the compensation apparatus may further determine, according to the frequency domain average window corresponding to the DMRS symbol, the time offset compensation information p (i) corresponding to the DMRS symbol based on the following formula:
(formula 3)
Wherein K is the length of one side of the frequency domain averaging window, NFFTLength information of frequency domain sequence for the DMRS, tauTATo make advance ofA time offset value is fixed or estimated. When tau isTAWhen limited to a fixed value, the required compensation factors can be stored in the table in advance, thereby reducing the amount of computation, but different compensation factors need to be stored for different bandwidths. More preferably, the value of K must satisfy the design of LTE systemUnder a fading channel, the value of K is generally less than or equal to 2; k is less than or equal to 2, the amount of memory consumed can be substantially reduced.
More preferably, the time offset compensation information includes p (i), i ═ 1, 2. Wherein,
p (-i) ═ real (P (i)) -j × imag (P (i)) (formula 4)
Therefore, the P (-i) can be determined according to the P (i), and P (0) is 1, so that the value of the P (i) is only required to be stored, and the storage space is reduced by half.
Fig. 3 shows a schematic diagram, preferably for frequency domain averaging processing of DMRS symbols in an OFDM symbol, according to an aspect of the present invention. The compensation obtaining unit 11 obtains time offset compensation information corresponding to a DMRS symbol corresponding to an OFDM symbol:
(formula 5)
Wherein K is less than or equal to 2; the sequence acquiring unit 12 acquires the frequency domain sequence corresponding to the DMRS symbol:
y (K-K), …, Y (K-1), Y (K +1), …, Y (K + K) (formula 6)
Wherein,(formula 7)
Here, X (k) is a representation of x (n) without time offset in the frequency domain(ii) a Time lapse τTAAnd (3) after:
y(n)＝x(n-τTA) (formula 8)
Thus, it is possible to prevent the occurrence of,
(formula 9)
Therefore, if the time offset compensation is not performed:
(formula 10)
And the information obtained by the target is:
(formula 11)
The compensation unit 13 performs time offset compensation processing on the y (k) according to p (i), thereby obtaining, by advance compensation:
(formula 12)
The averaging unit 14 performs averaging processing on the frequency domain sequence subjected to the time offset compensation processing to obtain a frequency domain averaging result corresponding to the DMRS symbol. So that:
(formula 13)
Wherein in a subsequent frequency domain equalization operation, the symbolCan be cancelled by conjugate multiplication of the channel estimation value and the data symbol.
In particular, data symbols are utilizedRepresenting data X subject to time biasdata(k) The channel estimation value is the result obtained by averaging the frequency domainIn frequency domain equalization operation, H (k) and Ydata(k) Conjugate multiplication, then we get:
(formula 14)
In the same way as the existing method, the time offsets on the data symbol and the DMRS symbol are compensated to obtain T (k) and Xdata(k) And then, the results obtained by conjugate multiplication are consistent, so that the method does not need to carry out additional calculation on the data symbols, and only needs to carry out calculation on the DMRS symbols.
Tables 1 and 2 show the comparison of the present invention with the prior art method in terms of the amount of computation, which can be divided into two parts, including the compensation calculation and the calculation to generate the compensation coefficient table:
TABLE 1 comparison of calculated amounts of Compensation calculations
Wherein,in the LTE system, the number of Resource Blocks (RBs) included in an uplink OFDM symbol,is the number of Subcarriers (SC) included in each resource block,which is the number of subcarriers used in the uplink OFDM symbol.
The invention only needs to calculate 2 DMRS symbols, while the prior art needs to calculate 12 data symbols and 2 DMRS symbols; in general, the K value is 2 or less, and thus the amount of calculation is reduced by 40%. In this case, P (0) ═ 1, and therefore the method of the present invention requires the calculation of the compensation calculation amountRather than that of
TABLE 2 comparison of calculated quantities to generate a table of compensation coefficients
In general, the K value is not more than 2.
Fig. 4 to 6 show simulation effect graphs under different channels and different simulation conditions. Fig. 4 and 5 show the block error rate performance for an additive white gaussian noise AWGN channel versus an ETU300 channel, showing that the receiver with time offset compensation performs better than without. Fig. 6 shows the noise power estimation in the AWGN channel, and if there is no time offset compensation, the noise power estimation value is larger than the true noise power, and especially the difference is more obvious in the high signal-to-noise ratio region. As can be seen from fig. 4 to 6 above, the performance of the method is close to that of the existing method, but the calculation amount is lower.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned. Furthermore, it is obvious that the word "comprising" does not exclude other elements or steps, and the singular does not exclude the plural. A plurality of units or means recited in the apparatus claims may also be implemented by one unit or means in software or hardware. The terms first, second, etc. are used to denote names, but not any particular order.
Claims (9)
1. A method for frequency domain averaging processing of DMRS symbols in an OFDM symbol, wherein the method comprises the steps of:
a, determining time offset compensation information P (i) corresponding to a DMRS symbol according to a frequency domain average window corresponding to the DMRS symbol corresponding to the OFDM symbol based on the following formula:
<mrow> <mi>P</mi> <mrow> <mo>(</mo> <mi>i</mi> <mo>)</mo> </mrow> <mo>=</mo> <msup> <mi>e</mi> <mrow> <mi>j</mi> <mo>&CenterDot;</mo> <mfrac> <mrow> <mn>2</mn> <mi>&pi;</mi> </mrow> <msub> <mi>N</mi> <mrow> <mi>F</mi> <mi>F</mi> <mi>T</mi> </mrow> </msub> </mfrac> <mo>&CenterDot;</mo> <msub> <mi>&tau;</mi> <mrow> <mi>T</mi> <mi>A</mi> </mrow> </msub> <mo>&CenterDot;</mo> <mi>i</mi> </mrow> </msup> <mo>,</mo> <mi>i</mi> <mo>=</mo> <mo>-</mo> <mi>K</mi> <mo>,</mo> <mo>-</mo> <mi>K</mi> <mo>+</mo> <mn>1</mn> <mo>,</mo> <mo>...</mo> <mo>,</mo> <mi>K</mi> </mrow>
wherein K is the length of one side of the frequency domain averaging window, NFFTIs the number of points of FFT, tau, corresponding to OFDM symbolsTAA time offset value predetermined or estimated in advance;
wherein, the method also comprises:
b, acquiring a frequency domain sequence corresponding to the DMRS symbol;
c, according to the time offset compensation information, performing time offset compensation processing on each item of the frequency domain sequence in the frequency domain average window;
d, averaging the frequency domain sequence subjected to the time offset compensation processing to obtain a frequency domain average result corresponding to the DMRS symbol.
2. The method of claim 1, wherein the time offset compensation information includes p (i), i ═ 1,2, …, K.
3. The method of claim 1 or 2, wherein K is less than or equal to 2.
4. The method according to claim 1 or 2, wherein said step d comprises:
-obtaining a weight sequence corresponding to a frequency domain sequence corresponding to the DMRS symbol;
-performing weighted averaging on the frequency domain sequences subjected to the time offset compensation processing according to the weight sequences corresponding to the frequency domain sequences corresponding to the DMRS symbols to obtain frequency domain averaging results corresponding to the DMRS symbols.
5. A compensation apparatus for performing frequency domain averaging processing on DMRS symbols in an OFDM symbol, wherein the apparatus comprises:
a compensation acquisition unit configured to determine, from a frequency domain average window corresponding to a DMRS symbol corresponding to an OFDM symbol, time offset compensation information p (i) corresponding to the DMRS symbol based on the following formula:
<mrow> <mi>P</mi> <mrow> <mo>(</mo> <mi>i</mi> <mo>)</mo> </mrow> <mo>=</mo> <msup> <mi>e</mi> <mrow> <mi>j</mi> <mo>&CenterDot;</mo> <mfrac> <mrow> <mn>2</mn> <mi>&pi;</mi> </mrow> <msub> <mi>N</mi> <mrow> <mi>F</mi> <mi>F</mi> <mi>T</mi> </mrow> </msub> </mfrac> <mo>&CenterDot;</mo> <msub> <mi>&tau;</mi> <mrow> <mi>T</mi> <mi>A</mi> </mrow> </msub> <mo>&CenterDot;</mo> <mi>i</mi> </mrow> </msup> <mo>,</mo> <mi>i</mi> <mo>=</mo> <mo>-</mo> <mi>K</mi> <mo>,</mo> <mo>-</mo> <mi>K</mi> <mo>+</mo> <mn>1</mn> <mo>,</mo> <mo>...</mo> <mo>,</mo> <mi>K</mi> </mrow>
wherein K is the length of one side of the frequency domain averaging window, NFFTPoints of FFT corresponding to OFDM symbolsNumber, length information of frequency domain sequence of the DMRS, τTAA time offset value predetermined or estimated in advance;
wherein, the device still includes:
a sequence acquisition unit, configured to acquire a frequency domain sequence corresponding to the DMRS symbol;
a compensation unit, configured to perform time offset compensation processing on each item of the frequency domain sequence in the frequency domain average window according to the time offset compensation information;
and an averaging unit, configured to perform averaging processing on the frequency domain sequence subjected to the time offset compensation processing to obtain a frequency domain averaging result corresponding to the DMRS symbol.
6. The compensation arrangement of claim 5, wherein the time offset compensation information includes P (i), i ═ 1,2, …, K.
7. A compensation arrangement according to claim 5 or 6, wherein the K is less than or equal to 2.
8. A compensation arrangement according to claim 5 or 6, wherein the averaging unit is configured to:
-obtaining a weight sequence corresponding to a frequency domain sequence corresponding to the DMRS symbol;
-performing weighted averaging on the frequency domain sequences subjected to the time offset compensation processing according to the weight sequences corresponding to the frequency domain sequences corresponding to the DMRS symbols to obtain frequency domain averaging results corresponding to the DMRS symbols.
9. A receiving apparatus for performing frequency domain averaging processing on DMRS symbols in OFDM symbols via an uplink channel, comprising the compensation device according to any one of claims 5 to 8.
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| CN101938435A (en) * | 2009-06-30 | 2011-01-05 | 中兴通讯股份有限公司 | Time bias estimation device and method for orthogonal frequency division multiplexing system |
| CN102325119A (en) * | 2011-09-19 | 2012-01-18 | 武汉邮电科学研究院 | Joint estimation method of time deviation and frequency deviation |
| CN102624514A (en) * | 2012-03-01 | 2012-08-01 | 东南大学 | Method for improving timing synchronous precision of wireless channel measurement |
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| CN101938435A (en) * | 2009-06-30 | 2011-01-05 | 中兴通讯股份有限公司 | Time bias estimation device and method for orthogonal frequency division multiplexing system |
| CN102325119A (en) * | 2011-09-19 | 2012-01-18 | 武汉邮电科学研究院 | Joint estimation method of time deviation and frequency deviation |
| CN102624514A (en) * | 2012-03-01 | 2012-08-01 | 东南大学 | Method for improving timing synchronous precision of wireless channel measurement |
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