DE102013106333A1 - SIGNAL GENERATING DEVICE AND METHOD IN A COMMUNICATION SYSTEM - Google Patents

Abstract

A signal generating apparatus in a communication system includes: a buffer configured to buffer a wideband signal and extract time domain data; a fast Fourier transform block (FFT) adapted to multiply the time domain data by a window function and to rapidly Fourier transform the resulting data; a community weight mask unit configured to apply a common weight mask by multiplying the transformed data by a common weight mask pattern; and a weighted summer bank arranged to generate a plurality of narrowband signals by multiplying the data to which the common weight mask has been applied with a weight pattern.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the priority of Korean Patent Application No. 10-2013-0040879 , filed April 15, 2013, which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

Field of the invention

Embodiments of the present invention relate to a communication system, and more particularly to an apparatus and method for generating a plurality of narrowband signals from a wideband signal through a filter bank in a communication system.

Description of the Prior Art

In a current communication system, research has been actively conducted to provide users with various operating grades (hereafter referred to as 'QoS') of high-speed services. In such a communication system, research has been actively conducted on various methods for stably transmitting large amounts of data at high speed through limited resources. In the current communication system, various methods have been proposed for the normal transmission and reception of large amounts of data by effectively exploiting a limited frequency band.

Meanwhile, the communication system sends / receives a wideband signal to efficiently use a limited frequency band, and a receiver of the communication system receives only signals in a certain frequency band corresponding to the receiver from the transmitted / received wideband signal, and normalizes services whose QoS is ensured to disposal. The receiver filters the transmitted / received wideband signal and outputs signals in the particular frequency band, that is, narrowband signals. At this time, the receiver only filters out narrowband signals containing data corresponding to the services that the users should be able to receive from the wideband signal, and then outputs the corresponding data to the users, thereby making the services available to the users.

However, when users are to be able to receive various services, the current communication system must receive a plurality of narrowband signals containing data corresponding to respective services, and needs a plurality of filters corresponding to the respective narrowband signals to output the narrowband signals from the wideband signal. In other words, the communication system must output the wideband signal as the narrowband signals to normally provide various services which the users are to be able to receive, and needs a plurality of filters for the respective narrowband signals to output the narrowband signals from the wideband signal.

In doing so, the complexity of the system is inevitably increased because the plurality of filters are used when the communication system filters the wideband signal through the filters to output the narrowband signals. And since the wideband signal is filtered by the plurality of filters, the filtering number may be increased, thereby degrading the performance of the system. In particular, as sampling frequency differences between the wideband signal and the narrowband signals are increased and the number of filters and filtering number increased, the complexity of the system may be further increased and the performance of the system may be even more degraded.

Therefore, the communication system needs a method for generating a plurality of narrow band signals from a wideband signal transmitted / received by a limited frequency band, that is, a signal generating method for outputting the wideband signal as the narrowband signals.

BRIEF SUMMARY OF THE INVENTION

An embodiment of the present invention is directed to a signal generation apparatus and a signal generation method in a communication system.

Another embodiment of the present invention is directed to a signal generating apparatus and a signal generating method which output a wideband signal transmitted / received by a limited frequency band as a plurality of narrow band signals.

Another embodiment of the present invention is directed to a signal generating apparatus and a signal generating method which output a wideband signal using a filter bank in a communication system as a plurality of narrowband signals.

Other objects and advantages of the present invention will be apparent from the following description, and become apparent by reference to the embodiments of the present invention. It will also be apparent to those skilled in the art to which the present invention pertains that the objects and advantages of the present invention can be achieved by the means as claimed and combinations thereof.

According to an embodiment of the present invention, a signal generating apparatus in a communication system includes: a buffer configured to buffer a wideband signal and to extract time domain data; a Fast Fourier Transform (FFT) block adapted to multiply the time domain data by a window function and to fast Fourier transform the resulting data; a community weight mask unit configured to apply a common weight mask by multiplying the transformed data by a common weight mask pattern; and a weighted summer bank arranged to generate a plurality of narrowband signals by multiplying the data to which the common weight mask has been applied with a weight pattern.

According to another embodiment of the present invention, a signal generating apparatus in a communication system includes: a buffer configured to buffer a wideband signal and to extract time domain data; an FFT block arranged to multiply the time domain data by a window function and to fast Fourier transform the resulting data; and a weight summer bank arranged to multiply the transformed data by a weight pattern containing a common weight mask pattern and to generate a plurality of narrow band signals.

According to another embodiment of the present invention, a signal generation method in a communication system includes: by time-domain data extraction by buffering a wideband signal; multiply the time-domain data with a window function and fast-Fourier transform the resulting data; and to generate a plurality of narrowband signals by multiplying the transformed data by a weight pattern.

BRIEF DESCRIPTION OF THE DRAWINGS

1 Fig. 10 is a diagram showing response characteristics of a filter bank in a communication system according to an embodiment of the present invention.

2 to 4 schematically show signal generation devices in a communication system according to embodiments of the present invention.

5 FIG. 10 is a flowchart showing a signal generation process of the signal generation apparatus in the communication system according to the embodiment of the present invention. FIG.

DESCRIPTION OF SPECIFIC EMBODIMENTS

The following is a more detailed description of embodiments of the present invention with reference to the accompanying drawings. However, the present invention may be embodied in various forms and is not to be considered limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. Throughout the disclosure, like reference numbers refer to like parts throughout the several figures and embodiments of the present invention.

The embodiments of the present invention provide a signal generation apparatus and a signal generation method in communication. In particular, the embodiments of the present invention provide a signal generating apparatus and a signal generating method for outputting a wideband signal transmitted / received by a certain frequency band as a plurality of narrowband signals.

Further, the embodiments of the present invention provide a signal generation apparatus and a signal generation method for generating a plurality of narrowband signals from a wideband signal through a filter bank to normally provide users with various QoS of services through a limited frequency band in a communication system. The communication system generates a plurality of narrowband signals containing data corresponding to services which the users are to be able to receive from the wideband signal using the filter bank.

That is, the communication system according to the embodiment of the present invention filters the wideband signal through the filter bank and generates the narrowband signals from the wideband signal, thereby providing various services which the users are to be able to receive normally. Since the communication system filters the wideband signal through the filterbank to output the narrowband signals, the number of filters for filtering and the filtering number can be minimized. As a result, the increase in the complexity of the system and the degradation of the performance of the system can be minimized. With reference to 1 Now, the filter bank in the communication system according to the embodiment of the present invention will be described in detail.

1 Fig. 10 is a diagram showing response characteristics of a filter bank in a communication system according to an embodiment of the present invention.

With reference to 1 The filter bank in the communication system filters a wideband signal into a plurality of narrowband signals. For example, the filter bank divides the entire frequency band of the wideband signal into M frequency bands 101 . 104 . 106 . 108 . 110 and 112 and filters the wideband signal into M narrowband signals corresponding to the respective M frequency bands 101 . 104 . 106 . 108 . 110 and 112 , That is, the communication system generates the M narrowband signals through the filter bank from the wideband signal. With reference to 2 to 4 Now, a signal generating apparatus for generating narrow band signals from a wideband signal through a filter bank in a communication system according to an embodiment of the present invention will be described in detail.

2 schematically shows the signal generating device in the communication system according to the embodiment of the present invention.

With reference to 2 The signal generating device includes a filter bank 200 which filters a wideband signal transmitted / received by a limited frequency band and generates a plurality of narrowband signals, for example M narrowband signals. The filter bank 200 contains first to Mth bandpass filters 210 to 220 and first to Mth decimetre 230 to 240 , The first to Mth bandpass filters 210 to 220 are adapted to filter the wideband signal for M frequency bands, that is, to filter out the M narrowband signals from the wideband signal. The first to Mth decimetre 230 to 240 are adapted to extract data corresponding to the M frequency bands from samples of the filtered M narrowband signals and to output narrowband signals containing the data corresponding to respective services.

In the filter bank 200 can be the first to Mth bandpass filters 210 to 220 Finite Impulse Response (FIR) or Infinite Impulse Response (IIR) filters. As with reference to 1 described filters the filter bank 200 the wideband signal after the M frequency bands. The first to Mth decimetre 230 to 240 Extract data corresponding to services that users are to be able to receive for the respective M frequency bands from the samples of the first through the M-th bandpass filters 210 to 220 filtered M narrowband signals in a predetermined time interval. At this time, the other data other than the extracted data is discarded to convert the sampling frequencies of the data.

If the filter bank 200 the first to Mth bandpass filters 210 to 220 contains, as in 2 The complexity of the system may be increased or the performance of the system may be degraded depending on the number of filters. With reference to 3 are now the Signal generating device for minimizing the complexity of the system and the deterioration of the performance of the system described in more detail.

3 schematically shows a signal generating device in a communication system according to another embodiment of the present invention.

With reference to 3 The signal generating device includes a filter bank 300 which filters a wideband signal transmitted / received by a limited frequency band and generates a plurality of narrowband signals, for example M narrowband signals. The filter bank 300 contains a buffer 310 , a block 320 for fast Fourier transform (FFT), a community weight mask unit 330 and a weighted summer bank 340 , The buffer 310 is set up to buffer the wideband signal. The FFT block 320 is adapted to fast Fourier transform the buffered wideband signal. The community weight mask unit 330 is adapted to apply a weight mask collectively to the transformed data. The Weighted Totalizer Bank 340 is adapted to set a weight pattern on the data to which the weight mask has been applied and to sum up the data.

In particular, the buffer stores 310 the filter bank 300 Broadband signals which are sequentially input, that is, data S (n) in a wideband time domain in accordance with a FIFO (First In - First Out) method.

The FFT block 320 read those in the buffer 320 stored data at a predetermined sampling interval N _offset multiplies the read data, that is, the input data with a window function, and then subjects the resulting data to fast Fourier transformation. The input data x _k (n) can be expressed as Equation 1 below, and that through the FFT block 320 transformed data y _k (m) can be expressed as Equation 2 below.

[Equation 1]

• x _k (n) = s (kN _offset + n), n = 0, 1, ..., N - 1

[Equation 2]

In Equation 2, γ (n) represents a window function for minimizing interference between frequencies, that is, M frequency bands. The FFT block 320 uses a Hamming window function, a Hanning window function or a Blackman window function as the window function. If doing the FFT block 320 For example, using a Hanning window function of length N, the window function γ (n) in Equation 2 can be expressed as Equation 3 below.

[Equation 3]

• γ (n) = 0.5 (1 - cos (2πn / N-1)), = 0, 1, ..., N - 1

The window function is applied to the input data x _k (n) when the FFT block 320 FFT to minimize frequency interference between the M frequency bands. If the frequency interference need not be taken into account, the window function γ (n) is set to 1 (γ (n) = 1) The common weight mask unit 330 multiplies the frequency values of the FFT block 320 output transformed data y _k (m) having a certain pattern, that is, a common weight mask pattern w (m). The from the community weight mask unit 330 Data multiplied by the common weight mask pattern w (m), that is, data z _k (m) obtained by applying the common weight mask to the transformed data y _k (m) can be expressed as Equation 4 below.

[Equation 4]

• z _k (m) = w (m) y _k (m), m = 0, 1, ..., N - 1, w (m) = c (-1) ^{m + 1}

In equation w (m) represents the common weight mask pattern as described above and is collectively multiplied by the frequency values of the transformed data. Specifically, the common-weight mask pattern is commonly multiplied regardless of the frequency bands of the transformed data corresponding to the M frequency bands. While the frequency values of the transformed data y _k (m) are changed, the size of the common weight mask pattern w (m) is constant, and the sign of the common weight mask pattern w (m) is alternately changed. As a result, the common weight mask pattern w (m) can be set as follows: ω (m) = c (-1) ^m .

The Weighted Totalizer Bank 340 contains M weighted summers corresponding to the respective M frequency bands, that is, a first weighted summer 342 , a second weighted summer 344 , ..., a Mth weighted summer 346 , The first weighted summer 342 , the second weighted summer 344 , ..., the Mth weighted summer 346 are arranged to extract data corresponding to services that the users are to be able to receive from the data z _k (m) to which the common weight mask has been applied, that is, to generate M narrowband signals as data corresponding to the M frequency banks. The weighted-summers bank 340 output signals, that is, those from the first weighted summer 342 , the second weighted summer 344 , ..., the Mth weighted summer 346 output M narrowband signals can be expressed as Equation 5 below. [Equation 5]

In Equation 5, s _i (k) represents a k-th sample of a narrowband signal in any ith frequency band of the M frequency bands, and w _i (m) represents a weight pattern for filtering the narrowband signal in the ith frequency band from the Data z _k (m) to which the community weight mask has been applied. The weight pattern w _i (m) can be set in various ways. Specifically, the weight pattern w _i (m) may be set to have a larger value in the narrowband signal of the frequency band to be filtered, that is, the narrowband signal in the ith frequency band, as the weight pattern for narrowband signals in FIG has other frequency bands. For example, the weight pattern w _i (m) may be expressed as Equation 6 below. In accordance with Equation 6, the weight pattern w _i (m) for the narrowband signal in the frequency band to be filtered is set to 1 and set to 0 for narrowband signals in other frequency bands.

[Equation 6]

When in Equation 6, the number of frequencies passing through the FFT block 320 transformed data y _k (m) is equal to N, Ω _{i represents} a group consisting of frequency numbers of frequencies included in a pass band of the filter among the N frequencies. That is, Ω _i corresponds to a group of M narrowband signals which are the weighted summer bank 340 by filtering the data z _k (m) to which N community weight masks have been applied, depending on the frequencies of the transformed data y _k (m).

Therefore, the first weighted summer sums 342 , the second weighted summer 344 , ..., the Mth weighted summer 346 the Weighted Totalizer Bank 340 only values corresponding to data which the users are to be allowed to receive among the data z _k (m) to which the N community weight masks have been applied, and generate M narrow band signals as the data corresponding to the respective M frequency bands. With reference to 4 Now a signal generating device in a communication system according to another embodiment of the present invention described in detail.

4 schematically shows a signal generating device in a communication system according to another embodiment of the present invention.

With reference to 4 The signal generating device includes a filter bank 400 which filters a wideband signal transmitted / received by a limited frequency band and generates a plurality of narrowband signals, for example M narrowband signals. The filter bank 400 contains a buffer 410 , an FFT block 420 and a weighted summer bank 430 , The buffer 410 is set up to buffer the wideband signal. The FFT block 420 is adapted to fast Fourier transform the buffered wideband signal. The Weighted Totalizer Bank 430 is set up to place a weight pattern on the transformed data and to sum up the data. Because of the buffer 410 and the FFT block 420 with reference to 3 have been described in detail, their detailed descriptions are omitted herein.

In the filter bank 400 contains the Weighted Totalizer Bank 430 M weighted summers corresponding to the respective M frequency bands, that is, a first weighted summer 432 , a second weight totalizer 434 , ..., a Mth weighted summer 436 as referring to 3 described weighted totalizer bank 430 , The first weighted summer 432 , the second weight summer 434 , ..., the Mth weighted summer 436 Contain the community weight mask pattern w (m) of the community weight mask unit 330 from 3 in the weight pattern w _i (m) and generate the M narrowband signals by multiplying those from the FFT block 420 output transformed data y _k (m) with the weight pattern w _i (m) containing the common weight mask pattern w (m).

The weight pattern w _i (m) containing the common weight mask pattern w (m) can be expressed as Equation 7 below. Since the multiplication of the transformed data y _k (m) by the common weight mask pattern w (m) and the weight pattern w _i (m) is explained with reference to FIG 3 has been described in detail, their detailed descriptions are omitted herein.

Equation 7

The first weighted summer 432 , the second weight summer 434 , ..., the Mth weighted summer 436 the Weighted Totalizer Bank 430 only sum values corresponding to the data which the users are to be allowed to receive among the N transformed data y _k (m), and generate M narrowband signals as the data corresponding to the M frequency bands. With reference to 5 Now, a method for generating a plurality of narrow-band signals from a wideband signal through a filter bank in a communication according to another embodiment of the present invention will be described in detail.

5 FIG. 10 is a flowchart showing a signal generation process of the signal generation apparatus in the communication system according to the embodiment of the present invention. FIG.

With reference to 5 In step S510, the signal generator extracts data in a wideband time domain by buffering a wideband signal transmitted / received by a limited frequency band. The signal generation apparatus extracts N time-domain signal samples by buffering.

In step S520, the signal generator FFT performs the wideband time domain data. In other words, the signal generation apparatus multiplies the N time-domain signal samples by a window function and then subjects the resultant data to fast Fourier transformation.

In step S530, the signal generator applies a common weight mask to the transformed data. In other words, the signal generator multiplies the transformed N time domain signal samples by the common weight mask pattern. In step S540, the signal generating device only sums values of data corresponding to services that the users are to be allowed to receive among the data to which the common weight mask has been applied, that is, multiplies the weighted data multiplied by the common weight mask pattern Pattern, whereby M narrow-band signals are generated as data corresponding to the M frequency bands. The signal generator may here multiply the transformed data, that is, the N transformed time domain signal samples, by the weight pattern containing the common weight mask pattern, thereby generating the M narrowband signals.

In the communication system according to the embodiment, the signal generation device and the signal generation method generate a plurality of narrowband signals by filtering a wideband signal through the filter bank, that is, extracting narrowband signals corresponding to data that services are to be able to receive from the wideband signal using the filter bank. As a result, the signal generation apparatus and the signal generation method can minimize the increase in the complexity of the system and the deterioration of the performance of the system depending on the number of filters and the filtering number, whereby various services can be normally provided to the users.

While the present invention has been described in terms of the specific embodiments, those skilled in the art will recognize that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• KR 10-2013-0040879 [0001]

Claims (11)

A signal generating apparatus in a communication system, comprising: a buffer configured to buffer a wideband signal and to extract time domain data; a fast Fourier transform block (FFT) adapted to multiply the time domain data by a window function and to rapidly Fourier transform the resulting data; a community weight mask unit configured to apply a common weight mask by multiplying the transformed data by a common weight mask pattern; and a weighted summer bank adapted to generate a plurality of narrowband signals by multiplying the data to which the common weight mask has been applied with a weight pattern. The signal generation apparatus of claim 1, wherein the common weight mask unit multiplies frequency values of the transformed data by the common weight mask pattern. A signal generating apparatus according to claim 1 or 2, wherein the size of the common weight mask pattern is constant and the sign of the common weight mask pattern is alternately changed in response to the frequency change of the transformed data. A signal generating apparatus according to any one of claims 1, 2 and 3, wherein the weight pattern has a larger value than a weight pattern in which frequency bands of data corresponding to the narrow band signals are different so as to filter only the data corresponding to the narrow band signals , A signal generating apparatus according to claim 4, wherein the weight pattern in the frequency bands of the respective data is set to 1 and set to 0 in other bands. A signal generation apparatus according to any one of claims 1 to 5, wherein the FFT block reads the time domain data at a predetermined sampling interval and multiplies the read data by the window function. A signal generating apparatus in a communication system, comprising: a buffer configured to buffer a wideband signal and to extract time domain data; an FFT block arranged to multiply the time domain data by a window function and to fast Fourier transform the resulting data; and a weight summer bank arranged to multiply the transformed data by a weight pattern containing a common weight mask pattern and to generate a plurality of narrow band signals. A signal generating apparatus according to claim 7, wherein the weight pattern in a frequency band of the corresponding data is set to 1 and set to 0 in other frequency bands and has a sign which is alternately changed in response to the frequency change of the transformed data. A signal generating apparatus according to claim 4 or 7, wherein the weighted summer bank comprises a plurality of weighted summers adapted to sum only data corresponding to the respective narrow band signals and to output the respective narrowband signals. A signal generation method in a communication system, comprising: by extracting time domain data by buffering a wideband signal; multiply the time-domain data with a window function and fast-Fourier transform the resulting data; and by multiplying the transformed data by a weight pattern to produce a plurality of narrowband signals. The signal generation apparatus of claim 10, further comprising applying a common weight mask by multiplying frequency values of the transformed data by a common weight mask pattern.

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