CN101895489B - Filtering method and device for channel estimation - Google Patents
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Abstract
The invention provides a filtering method and a filtering device for channel estimation. The method comprises the following steps of: determining a filtering threshold for each code combination transmission channel; carrying out channel estimation filtering on each code combination transmission channel according to the filtering threshold of each code combination transmission channel; and retaining channel estimation taps of which the energy value or the amplitude is greater than the filtering threshold in each code combination transmission channel. The filtering device comprises a filtering threshold determination module and a channel estimation filtering module. The filtering method and the filtering device can improve the demodulation performance of the service signal of the low-power code combination transmission channel on the premise of guaranteeing the demodulation performance of the service signal of the high-power code combination transmission channel.
Description
Technical Field
The present invention relates to the field of wireless communication technologies, and in particular, to a filtering method and a filtering device for terminal channel estimation in a time Division Synchronous Code Division Multiple Access (TD-SCDMA) system.
Background
The TD-SCDMA system demodulates user data by adopting joint detection, and the application of a joint detection algorithm is based on the premise that the channel impulse response of each user can be accurately estimated. The channel estimation of TD-SCDMA system adopts classic Steiner estimator, it is a low-cost channel estimation method to use this estimator, construct Midamble code of every user according to certain rule through a basic Midamble code, thus make Midamble code system matrix at the receiving end have cyclic correlation, in this way, can use FFT (fast Fourier transform) and IFFT (inverse fast Fourier transform) to calculate and get the estimated value of channel. Firstly, estimating an original channel estimation value, setting a threshold according to a channel estimation tap energy peak value of received Midamble code data, and removing noise through the threshold to obtain a final channel estimation value.
When multiple services are parallel in the TD-SCDMA system, different services are mapped to different code Composite Transport channels (CCTrCH), each CCTrCH corresponds to one or more physical channels and is transmitted in one time slot, and power control is performed on different cctrchs respectively. Under the condition that the power difference between the CCTRCHs is large, a threshold is set according to the energy peak value of each tap, the energy of each tap of the CCTRCH with small power is possibly below the threshold, the channel estimation values are all zero, and the CCTRCH with small power cannot be demodulated correctly, so that the signal demodulation quality is influenced. As shown in fig. 1, CCTRCH1 has 1 channel window, the signal energy is weak, CCTRCH2 has 5 channel windows, the signal energy is strong, and the filtering threshold Th is set according to the energy peak value Power2 of each tap, so that all taps of CCTRCH1 are below the threshold, the channel estimation is all zero, and CCTRCH1 cannot be correctly demodulated.
Disclosure of Invention
The applicant has studied the drawbacks of the prior art, which correspond to the prior art, if the threshold is lowered in the manner of determining the threshold in the prior art, as shown in fig. 1, the CCTRCH1 can be detected, but the lowering of the threshold introduces noise, thereby affecting the demodulation performance of the high-power CCTRCH service signal.
The technical problem to be solved by the present invention is to provide a filtering method for channel estimation, which improves the demodulation performance of low-power CCTRCH service signals on the premise of ensuring the demodulation performance of high-power CCTRCH service signals.
In order to solve the above technical problem, the present invention provides a filtering method for channel estimation, including: and respectively determining a filtering threshold for each code combination transmission channel, respectively carrying out channel estimation filtering on each code combination transmission channel according to the respective filtering threshold of the code combination transmission channel, and reserving a channel estimation tap of which the energy value or amplitude value is greater than the filtering threshold in each code combination transmission channel.
Further, the method also has the following characteristics:
for a code combination transmission channel, determining a filtering threshold of the code combination transmission channel according to an energy value of a channel estimation tap in the code combination transmission channel; reserving a channel estimation tap with the energy value larger than the filtering threshold in the code combined transmission channel, and filtering the channel estimation tap with the energy value smaller than the filtering threshold; or, determining the filtering threshold of the code combination transmission channel according to the amplitude value of the channel estimation tap in the code combination transmission channel; and reserving the channel estimation taps with the amplitude values larger than the filtering threshold in the code combination transmission channel, and filtering the channel estimation taps with the amplitude values smaller than the filtering threshold.
Further, the method also has the following characteristics:
when determining a filtering threshold according to an energy value of a channel estimation tap in a code combination transmission channel, the filtering threshold of the code combination transmission channel is as follows: the product of the energy value of the channel estimation tap with the maximum energy in the code combination transmission channel and a filter coefficient lambda 1, wherein the filter coefficient lambda 1 is a real number which is larger than 0 and smaller than 1; when the filtering threshold is determined according to the amplitude value of the channel estimation tap in the code combination transmission channel, the filtering threshold of the code combination transmission channel is as follows: the code combines the product of the amplitude value of the channel estimation tap with the largest amplitude in the transmission channel and the filter coefficient U1, the filter coefficient U1 is a real number greater than 0 and less than 1.
Further, the method also has the following characteristics:
performing noise removal processing on the filtered channel estimation, specifically including: determining the noise threshold of each code combination transmission channel according to the energy value of a channel estimation tap in each code combination transmission channel; reserving channel estimation taps with energy values larger than a noise threshold in each code combination transmission channel, and filtering the channel estimation taps with energy values smaller than the noise threshold; or, determining the noise threshold of each code combination transmission channel according to the amplitude value of the channel estimation tap in the code combination transmission channel; and reserving channel estimation taps with amplitude values larger than the noise threshold in each code combination transmission channel, and filtering the channel estimation taps with the amplitude values smaller than the noise threshold.
Further, the method also has the following characteristics:
when determining a noise threshold according to the energy value of a channel estimation tap in a code combination transmission channel, regarding a code combination transmission channel, taking the product of the energy mean value of the channel estimation tap smaller than the filtering threshold of the code combination transmission channel and a noise coefficient lambda 2 as the noise threshold, wherein lambda 2 is a real number larger than 1; when the noise threshold is determined according to the amplitude value of the channel estimation tap in the code combination transmission channel, for a code combination transmission channel, the product of the average value of the amplitudes of the channel estimation taps which are smaller than the filtering threshold of the code combination transmission channel and the noise coefficient lambda 3 is used as the noise threshold, and lambda 3 is a real number which is larger than 1.
In order to solve the above technical problem, the present invention further provides a filtering apparatus for channel estimation, including a filtering threshold determining module and a channel estimation filtering module, where the filtering threshold determining module is configured to determine a filtering threshold for each code combination transmission channel; and the channel estimation filtering module is used for respectively carrying out channel estimation filtering on each code combination transmission channel according to the respective filtering threshold of the code combination transmission channel, and reserving a channel estimation tap of which the energy value or amplitude value is greater than the filtering threshold in each code combination transmission channel.
Further, the filtering device also has the following characteristics:
the filtering threshold determining module is further configured to determine a filtering threshold of the code combination transmission channel according to an energy value or an amplitude value of a channel estimation tap in the code combination transmission channel; the channel estimation filtering module is further configured to, when the filtering threshold determining module determines the filtering threshold according to the energy value of the channel estimation tap, reserve the channel estimation tap of which the energy value in the code combination transmission channel is greater than the filtering threshold, and filter the channel estimation tap of which the energy value is less than the filtering threshold; and the filtering threshold determining module is further configured to, when determining the filtering threshold according to the amplitude value of the channel estimation tap, reserve the channel estimation tap of which the amplitude value is greater than the filtering threshold in the code combination transmission channel, and filter the channel estimation tap of which the amplitude value is less than the filtering threshold.
Further, the filtering device also has the following characteristics:
the filtering threshold determining module is further configured to, when determining the filtering threshold according to the energy value of the channel estimation tap in the code combination transmission channel, take a product of the energy value of the channel estimation tap with the largest energy in the code combination transmission channel and a filtering coefficient λ 1 as the filtering threshold of the code combination transmission channel, where the filtering coefficient λ 1 is a real number greater than 0 and smaller than 1; and the filter module is further configured to, when determining the filter threshold according to the amplitude value of the channel estimation tap in the code combination transmission channel, take a product of the amplitude value of the channel estimation tap with the largest amplitude in the code combination transmission channel and a filter coefficient U1 as the filter threshold of the code combination transmission channel, where the filter coefficient U1 is a real number greater than 0 and smaller than 1.
Further, the filtering device also has the following characteristics:
the device also comprises a noise threshold determining module and a noise removing module; the input end of the noise removal module is connected with the output end of the channel estimation filtering module; the noise threshold determination module is used for determining the noise threshold of the code combination transmission channel according to the energy value or amplitude value of the channel estimation tap in the code combination transmission channel; a noise removing module, configured to process the channel estimation taps output by the channel estimation filtering module when the noise threshold determining module determines the noise threshold according to the energy values of the channel estimation taps, reserve channel estimation taps in each code combination transmission channel whose energy values are greater than the noise threshold of each code combination transmission channel, and filter channel estimation taps whose energy values are less than the noise threshold; and the noise threshold determining module is further configured to, when determining the noise threshold according to the amplitude value of the channel estimation tap, process the channel estimation tap output by the channel estimation filtering module, reserve the channel estimation tap of which the amplitude value is greater than the noise threshold of each code combination transmission channel in each code combination transmission channel, and filter the channel estimation tap of which the amplitude value is less than the noise threshold.
Further, the filtering device also has the following characteristics:
the noise threshold determining module is further configured to determine a noise threshold according to an energy value of a channel estimation tap in the code combination transmission channel, and use a product of an energy average value of the channel estimation tap in the code combination transmission channel, which is smaller than a filtering threshold of the code combination transmission channel, and a noise coefficient λ 2 as the noise threshold of the combination transmission channel, where λ 2 is a real number greater than 1; and when determining the noise threshold according to the amplitude value of the channel estimation tap in the code combination transmission channel, taking the product of the average amplitude value of the channel estimation tap in the code combination transmission channel, which is smaller than the filtering threshold of the code combination transmission channel, and a noise coefficient λ 3 as the noise threshold of the code combination transmission channel, where λ 3 is a real number greater than 1.
The method of the invention improves the demodulation performance of the low-power CCTRCH service signal on the premise of ensuring the demodulation performance of the high-power CCTRCH service signal.
Drawings
FIG. 1 is a diagram illustrating a prior art method for determining a filtering threshold based on energy peaks of all taps;
FIG. 2 is a flow chart of a method of filtering channel estimates in an embodiment;
FIG. 3 is a diagram illustrating a filtering method for channel estimation according to an embodiment;
FIG. 4 is a diagram illustrating a specific filtering process according to a first embodiment;
FIG. 5 is a diagram illustrating the filtering result according to one embodiment;
fig. 6 is a schematic diagram of a noise removing process in the second embodiment.
Detailed Description
In this embodiment, the filtering apparatus for channel estimation includes a filtering threshold determining module, a channel estimation filtering module, a noise threshold determining module, and a noise removing module, where an input end of the noise removing module is connected to an output end of the channel estimation filtering module.
A filtering threshold determining module, configured to determine a filtering threshold for each code combination transmission channel; for a code combination transmission channel, determining a filtering threshold of the code combination transmission channel according to an energy value or an amplitude value of a channel estimation tap in the code combination transmission channel; when determining a filtering threshold according to the energy value of a channel estimation tap in a code combination transmission channel, taking the product of the energy value of the channel estimation tap with the maximum energy in the code combination transmission channel and a filtering coefficient lambda 1 as the filtering threshold of the code combination transmission channel, wherein lambda 1 is a real number which is greater than 0 and less than 1; when determining the filtering threshold according to the amplitude value of the channel estimation tap in the code combination transmission channel, taking the product of the amplitude value of the channel estimation tap with the maximum amplitude in the code combination transmission channel and the filtering coefficient U1 as the filtering threshold of the code combination transmission channel, wherein U1 is a real number which is greater than 0 and less than 1.
A channel estimation filtering module, configured to reserve a channel estimation tap of which energy value is greater than the filtering threshold in the code combination transmission channel and filter a channel estimation tap of which energy value is less than the filtering threshold when the filtering threshold determination module determines the filtering threshold according to the energy value of the channel estimation tap; and the filtering threshold determining module is further configured to, when determining the filtering threshold according to the amplitude value of the channel estimation tap, reserve the channel estimation tap of which the amplitude value is greater than the filtering threshold in the code combination transmission channel, and filter the channel estimation tap of which the amplitude value is less than the filtering threshold.
The noise threshold determination module is used for determining the noise threshold of the code combination transmission channel according to the energy value or amplitude value of the channel estimation tap in the code combination transmission channel; specifically, the method comprises the following steps: when determining a noise threshold according to the energy value of a channel estimation tap in a code combination transmission channel, taking the product of the energy mean value of the channel estimation tap in the code combination transmission channel, which is smaller than the filtering threshold of the code combination transmission channel, and a noise coefficient lambda 2 as the noise threshold of the combination transmission channel, wherein lambda 2 is a real number greater than 1; when the noise threshold is determined according to the amplitude value of the channel estimation tap in the code combination transmission channel, the product of the average value of the amplitudes of the channel estimation tap in the code combination transmission channel, which is smaller than the filtering threshold of the code combination transmission channel, and a noise coefficient lambda 3 is taken as the noise threshold of the code combination transmission channel, wherein lambda 3 is a real number larger than 1.
A noise removing module, configured to process the channel estimation taps output by the channel estimation filtering module when the noise threshold determining module determines the noise threshold according to the energy values of the channel estimation taps, reserve channel estimation taps in each code combination transmission channel whose energy values are greater than the noise threshold of each code combination transmission channel, and filter channel estimation taps whose energy values are less than the noise threshold; and the noise threshold determining module is further configured to, when determining the noise threshold according to the amplitude value of the channel estimation tap, process the channel estimation tap output by the channel estimation filtering module, reserve the channel estimation tap of which the amplitude value is greater than the noise threshold of each code combination transmission channel in each code combination transmission channel, and filter the channel estimation tap of which the amplitude value is less than the noise threshold.
As shown in fig. 2, in this embodiment, the method for filtering channel estimates includes:
for a code combination transmission channel, determining a filtering threshold of the code combination transmission channel according to an energy peak value of a tap with the maximum energy value in all channel estimation taps included in the code combination transmission channel;
For a code combined transmission channel, reserving a channel estimation tap larger than the filtering threshold of the code combined transmission channel, and setting the channel estimation tap smaller than the filtering threshold to be 0 to obtain the filtered channel estimation.
The invention is further illustrated below in two specific examples:
in a specific embodiment, as shown in fig. 3, a filtering method for channel estimation includes:
basic_midamble_fft＝fft(basic_midamble)；
received_midamble_fft＝fft(received_midamble)；
channel＝ifft(received_midamble_fft·/basic_midamble_fft)
wherein/represents the division of the two array corresponding numbers;
the energy per channel estimate tap is: power ═ real (channel) 2+ imag (channel) 2;
for a CCTrCH, multiplying the energy peak value of the tap with the maximum energy value in all channel estimation taps included in the CCTrCH by a filter coefficient to be used as a filter threshold Th1 for determining the CCTrCH;
Th1＝max(power)*λ1
wherein, the filter coefficient lambda 1 is a real number, and the value range is 0 < lambda 1 < 1. The preferred value of the filter coefficient lambda 1 can also be obtained by empirical values of system tests.
comparing the energy peak values of all taps in each CCTRCH with the filtering threshold Th1, reserving the channel estimation tap larger than the filtering threshold Th1 as an effective tap, and setting the channel estimation tap smaller than the filtering threshold Th1 to 0 to obtain the filtered channel estimation.
As shown in fig. 5, in the first embodiment, P-128 is the basic Midamble code length, K-8 is the number of channel windows,is the channel estimation window length. As shown in the figure, the CCTRCH1 has one channel window, the CCTRCH2 has 5 channel windows (i.e., 2 nd to 6 Th channel windows), and by the method of the first embodiment, the filtering threshold determined for the CCTRCH1 is Th1, the filtering threshold determined for the CCTRCH2 is Th2, filtering is performed according to Th1 in the CCTRCH1, and filtering is performed according to Th2 in the CCTRCH2The wave, CCTRCH1 with low power can also be effectively demodulated.
In the above embodiment, when the channel estimation in step 302 is filtered, the filtering threshold adopted for each code combination transmission channel is the product of the energy value of the channel estimation tap with the largest energy in the code combination transmission channel and the filtering coefficient λ 1. The filtering threshold may be selected in other ways besides the above-mentioned way: the product of the average of the last X1(X1 is an integer greater than 1) energy values in the ordering of the energy values of the channel estimation taps from large to small in the code-combined transmission channel and the filter coefficient M1(M1 is a real number greater than 1).
In addition, in addition to the above-mentioned manner of using the energy parameter as the filtering threshold, amplitude values may also be used, for example: the filtering threshold adopted for each code combination transmission channel is the product of the amplitude value of the channel estimation tap with the maximum amplitude value in the code combination transmission channel and a filtering coefficient U1(U1 is a real number which is more than 0 and less than 1); or, the product of the average value of the last Y1(Y1 is an integer greater than 1) amplitude values and the filter coefficient N1(N1 is a real number greater than 1) in the ordering of the amplitude values of the channel estimation taps in the code combination transmission channel from large to small, when filtering, the channel estimation taps in the code combination transmission channel with the amplitude values greater than the filter threshold calculated based on the amplitude values are reserved, and the channel estimation taps with the amplitude values less than the filter threshold are filtered.
The second embodiment is as follows:
the second embodiment is based on the first embodiment, and performs noise removal after the first embodiment completes the filtering process, where the noise removal process is as follows:
Th2＝mean(power＜Th1)*λ2
wherein λ 2 > 1 is a noise threshold coefficient; the optimal value of λ 2 may be a real number between 3 and 8, and may also be obtained by an empirical value of a system experiment.
In the first embodiment, compared with the second embodiment, noise is further removed, and more accurate channel estimation is obtained.
In the second embodiment, energy is averaged from the channel estimation taps of each code combination transmission channel that are smaller than the filtering threshold of the code combination transmission channel, and the product of the energy average and the noise coefficient λ 2 is used as the noise threshold, where λ 2 is a real number greater than 1.
In addition, in addition to the above-mentioned manner of using the energy parameter as the noise threshold, an amplitude value may also be used, and the noise threshold used by each code combination transmission channel may be the following value:
the average value of the amplitudes of all channel estimation taps in the code combination transmission channel, which are smaller than the filtering threshold, is multiplied by a noise coefficient lambda 3, wherein lambda 3 is a coefficient larger than 1. And when the noise is removed, reserving a channel estimation tap of which the amplitude value is greater than the noise threshold calculated based on the amplitude mean value in the code combination transmission channel, and filtering the channel estimation tap of which the amplitude value is less than the noise threshold.
In the method, the filtering threshold is respectively determined for each code combination transmission channel according to the peak value of the signal, the noise threshold is determined for each code combination transmission channel according to the noise signal after the channel estimation tap of each code combination transmission channel is filtered, the noise is further removed, and the demodulation performance of the low-power CCTRCH service signal is improved on the premise of ensuring the demodulation performance of the high-power CCTRCH service signal
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it should be understood that various changes and modifications can be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
Claims (8)
1. A method of filtering channel estimates, comprising:
determining a filtering threshold for each code combination transmission channel, performing channel estimation filtering on each code combination transmission channel according to the respective filtering threshold of the code combination transmission channel, and reserving a channel estimation tap of which the energy value or amplitude value is greater than the filtering threshold in each code combination transmission channel; wherein,
for a code combination transmission channel, determining a filtering threshold of the code combination transmission channel according to an energy value of a channel estimation tap in the code combination transmission channel; reserving a channel estimation tap with the energy value larger than the filtering threshold in the code combined transmission channel, and filtering the channel estimation tap with the energy value smaller than the filtering threshold; or,
determining a filtering threshold of the code combination transmission channel according to the amplitude value of a channel estimation tap in the code combination transmission channel; and reserving the channel estimation taps with the amplitude values larger than the filtering threshold in the code combination transmission channel, and filtering the channel estimation taps with the amplitude values smaller than the filtering threshold.
2. The method of claim 1,
when determining a filtering threshold according to an energy value of a channel estimation tap in a code combination transmission channel, the filtering threshold of the code combination transmission channel is as follows: the product of the energy value of the channel estimation tap with the maximum energy in the code combination transmission channel and a filter coefficient lambda 1, wherein the filter coefficient lambda 1 is a real number which is larger than 0 and smaller than 1;
when the filtering threshold is determined according to the amplitude value of the channel estimation tap in the code combination transmission channel, the filtering threshold of the code combination transmission channel is as follows: the code combines the product of the amplitude value of the channel estimation tap with the largest amplitude in the transmission channel and the filter coefficient U1, the filter coefficient U1 is a real number greater than 0 and less than 1.
3. The method of claim 1 or 2,
performing noise removal processing on the filtered channel estimation, specifically including: determining the noise threshold of each code combination transmission channel according to the energy value of a channel estimation tap in each code combination transmission channel; reserving channel estimation taps with energy values larger than a noise threshold in each code combination transmission channel, and filtering the channel estimation taps with energy values smaller than the noise threshold; or,
determining the noise threshold of each code combination transmission channel according to the amplitude value of the channel estimation tap in the code combination transmission channel; and reserving channel estimation taps with amplitude values larger than the noise threshold in each code combination transmission channel, and filtering the channel estimation taps with the amplitude values smaller than the noise threshold.
4. The method of claim 3,
when determining a noise threshold according to the energy value of a channel estimation tap in a code combination transmission channel, regarding a code combination transmission channel, taking the product of the energy mean value of the channel estimation tap smaller than the filtering threshold of the code combination transmission channel and a noise coefficient lambda 2 as the noise threshold, wherein lambda 2 is a real number larger than 1;
when the noise threshold is determined according to the amplitude value of the channel estimation tap in the code combination transmission channel, for a code combination transmission channel, the product of the average value of the amplitudes of the channel estimation taps which are smaller than the filtering threshold of the code combination transmission channel and the noise coefficient lambda 3 is used as the noise threshold, and lambda 3 is a real number which is larger than 1.
5. A filtering device for channel estimation comprises a filtering threshold determining module and a channel estimation filtering module,
the filtering threshold determining module is used for determining a filtering threshold for each code combination transmission channel;
the channel estimation filtering module is used for respectively carrying out channel estimation filtering on each code combination transmission channel according to the respective filtering threshold of the code combination transmission channel, and reserving a channel estimation tap of which the energy value or amplitude value is greater than the filtering threshold in each code combination transmission channel; wherein,
the filtering threshold determining module is further configured to determine a filtering threshold of the code combination transmission channel according to an energy value or an amplitude value of a channel estimation tap in the code combination transmission channel;
the channel estimation filtering module is further configured to, when the filtering threshold determining module determines the filtering threshold according to the energy value of the channel estimation tap, reserve the channel estimation tap of which the energy value in the code combination transmission channel is greater than the filtering threshold, and filter the channel estimation tap of which the energy value is less than the filtering threshold; and the filtering threshold determining module is further configured to, when determining the filtering threshold according to the amplitude value of the channel estimation tap, reserve the channel estimation tap of which the amplitude value is greater than the filtering threshold in the code combination transmission channel, and filter the channel estimation tap of which the amplitude value is less than the filtering threshold.
6. Filter device as claimed in claim 5,
the filtering threshold determining module is further configured to, when determining the filtering threshold according to the energy value of the channel estimation tap in the code combination transmission channel, take a product of the energy value of the channel estimation tap with the largest energy in the code combination transmission channel and a filtering coefficient λ 1 as the filtering threshold of the code combination transmission channel, where the filtering coefficient λ 1 is a real number greater than 0 and smaller than 1; and the filter module is further configured to, when determining the filter threshold according to the amplitude value of the channel estimation tap in the code combination transmission channel, take a product of the amplitude value of the channel estimation tap with the largest amplitude in the code combination transmission channel and a filter coefficient U1 as the filter threshold of the code combination transmission channel, where the filter coefficient U1 is a real number greater than 0 and smaller than 1.
7. The filtering apparatus of claim 5 or 6, wherein the apparatus further comprises a noise threshold determination module and a noise removal module; the input end of the noise removal module is connected with the output end of the channel estimation filtering module;
the noise threshold determination module is used for determining the noise threshold of the code combination transmission channel according to the energy value or amplitude value of the channel estimation tap in the code combination transmission channel;
a noise removing module, configured to process the channel estimation taps output by the channel estimation filtering module when the noise threshold determining module determines the noise threshold according to the energy values of the channel estimation taps, reserve channel estimation taps in each code combination transmission channel whose energy values are greater than the noise threshold of each code combination transmission channel, and filter channel estimation taps whose energy values are less than the noise threshold; and the noise threshold determining module is further configured to, when determining the noise threshold according to the amplitude value of the channel estimation tap, process the channel estimation tap output by the channel estimation filtering module, reserve the channel estimation tap of which the amplitude value is greater than the noise threshold of each code combination transmission channel in each code combination transmission channel, and filter the channel estimation tap of which the amplitude value is less than the noise threshold.
8. Filter device as claimed in claim 7,
the noise threshold determining module is further configured to determine a noise threshold according to an energy value of a channel estimation tap in the code combination transmission channel, and use a product of an energy average value of the channel estimation tap in the code combination transmission channel, which is smaller than a filtering threshold of the code combination transmission channel, and a noise coefficient λ 2 as the noise threshold of the combination transmission channel, where λ 2 is a real number greater than 1; and when determining the noise threshold according to the amplitude value of the channel estimation tap in the code combination transmission channel, taking the product of the average amplitude value of the channel estimation tap in the code combination transmission channel, which is smaller than the filtering threshold of the code combination transmission channel, and a noise coefficient λ 3 as the noise threshold of the code combination transmission channel, where λ 3 is a real number greater than 1.
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| CN101120560A (en) * | 2005-02-11 | 2008-02-06 | 高通股份有限公司 | Selection of a thresholding parameter for channel estimation |
| CN101218750A (en) * | 2005-03-18 | 2008-07-09 | 美商内数位科技公司 | Channel estimation enhanced LMS equalizer |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101120560A (en) * | 2005-02-11 | 2008-02-06 | 高通股份有限公司 | Selection of a thresholding parameter for channel estimation |
| CN101218750A (en) * | 2005-03-18 | 2008-07-09 | 美商内数位科技公司 | Channel estimation enhanced LMS equalizer |
Non-Patent Citations (1)
| Title |
|---|
| 罗志年 等.一种新的TD-SCDMA信道估计改进方法.《湖南大学学报》.2008,第35卷(第3期),第72-75页. * |
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| CN101895489A (en) | 2010-11-24 |
| WO2010133109A1 (en) | 2010-11-25 |
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