KR100560388B1 - Apparatus and method for formatting baseband physical channel formatting and orthogonal frequency division multiple access communication system there of - Google Patents

Abstract

The present invention relates to an apparatus and method for forming a baseband physical channel in an orthogonal frequency division multiple access (OFDMA) wireless communication system.

According to the present invention, a control channel including a pilot channel is generated according to a control command received from a higher layer, and data about video or audio received from a higher layer is modulated into multiple levels. Then, after gain-adjusting the data modulated to multiple levels and the control data for the control channel for each channel, these data are combined and mapped in the frequency space. In addition, time-space mapping is performed by converting time-specific allocation positions of video, audio data, and control data mapped in the frequency space. In this case, the frequency domain order of the data mapped in the time space is changed to change the baseband physical channel (-9.381MHz). To +9.381 MHz). Thereafter, the data mapped to the frequency space is converted into a frame of a time domain that can be loaded on a baseband physical channel and transmitted.

Through this, it is possible to support a variety of services using a multi-carrier, for this purpose also supports a variety of modulation schemes.

Baseband Physical Channels, OFDMA, Resource / Logic Space Mapping, Modulators

Description

Baseband physical channel forming apparatus and method thereof, and ODDMA wireless communication system including the same.

1 is a block diagram of a wireless communication system according to the prior art.

2 is a block diagram of an OFDMA wireless communication system according to an embodiment of the present invention.

FIG. 3 is a detailed internal configuration diagram of the baseband physical channel forming apparatus shown in FIG. 2.

FIG. 4 is a diagram illustrating in detail an internal configuration of the control channel generating unit shown in FIG. 3.

FIG. 5 is a diagram illustrating an internal configuration of the multilevel modulator shown in FIG. 3.

FIG. 6 is a diagram illustrating an internal configuration of a resource space mapping unit illustrated in FIG. 3.

FIG. 7 is a diagram illustrating an internal configuration of the logical space mapping unit illustrated in FIG. 3.

8 is a flowchart sequentially illustrating an operation process of the baseband physical channel forming apparatus illustrated in FIG. 3.

The present invention relates to an orthogonal frequency division multiple access (OFDMA) wireless communication system, and more particularly, to an apparatus and method for forming a baseband physical channel and a wireless communication modulation system including the same.

1 is a block diagram of a wireless communication system according to the prior art, in which a conventional wireless communication system 100 includes an upper layer interface unit 110, a baseband physical channel former 120, a pulse shaping filter 130, and a high frequency converter. 140 and antenna 150.

The upper layer interface unit 110 transfers the data received from the upper layer (eg, L2, L3 layer, and L1 control unit) to the baseband physical channel former 120, and the baseband physical channel former 120 provides a service. The star data is transmitted to the pulse shaping filter 130 according to the type of the physical channel.

Thereafter, the high frequency converter 130 converts the baseband analog signal received from the pulse shaping filter 120 into a high frequency region to radiate to the air through the antenna 140.

However, such a wireless communication modulation system is extremely suitable for the next generation wireless communication system using multiple carriers that require modulation mapping of various transmission rates according to the type of service because the physical channel format is extremely limited.

As a related technology, the right holder has a patent of [Korea Patent and Communications Institute] [patent name: baseband physical channel forming apparatus and method thereof and wireless communication base station modulation system using same and its operation method, registration number: 10-413969] This is to form and provide a variety of physical channels that can provide high-speed, high-capacity multimedia communication services such as voice, data and video in the third generation or more wireless communication system.

However, the above-described technique relates to a physical channel forming apparatus and a method suitable for a wireless communication system using a code division multiple access (CDMA) method, which, unlike a wireless communication system using an OFDMA method, fades during broadband communication ( fading often occurs. This, in turn, causes performance degradation of the wireless communication system.

Accordingly, there is a need for a physical channel forming apparatus and a method for efficiently supporting a service-specific mapping scheme using a plurality of sub-carriers that can overcome fading occurring in broadband communication.

The technical problem to be solved by the present invention is to solve this problem, by supporting a variety of modulation schemes to support a variety of services according to the OFDMA scheme, by varying the amount of data (variably) in the same channel environment An object of the present invention is to provide a baseband physical channel forming apparatus and method for transmitting the same, and an OFDMA wireless communication system including the same.

A baseband physical channel forming apparatus according to a feature of the present invention for achieving the above object is a baseband physical channel forming apparatus in an orthogonal frequency division multiple access (OFDMA) wireless communication system, the baseband physical channel forming apparatus, the control command received from a higher layer A control channel generator for generating a control channel including a pilot channel according to the control channel; A multi-level modulator configured to read data related to video or audio from a dual port memory storing data received from the upper layer and to modulate the data to a multi-level; A channel-specific gain control unit configured to gain-adjust the multi-level modulated data and the control data regarding the generated control channel for each channel; A resource space mapping unit for combining the gain-adjusted data and then mapping the combined data to frequency space; A logical space mapping unit configured to perform time-space mapping by converting time-specific allocation positions of the video, audio data, and control data; And a time frequency converter configured to change a frequency domain order of the data mapped to the time space to form a baseband physical channel.

And a data mixer for multiplying the data output from the time frequency converter by an appropriate sequence such that the data value received from the upper layer has a random distribution. A fast inverse Fourier transform unit for converting and outputting data output from the data mixer into frames in a time domain that can be loaded on the formed physical channel; A guard section inserting section for inserting a guard section into a frame of a time domain output from the fast inverse Fourier transform section; And a gain adjuster configured to adjust a gain for power control of the frame into which the guard period is inserted.

In addition, an OFDMA wireless communication system according to an aspect of the present invention, a processor controller for processing and controlling data related to video or audio received from a higher layer; A dual port memory for storing the processed data; The received data is mapped to the frequency space, the time-domain mapping is performed by converting the time-specific allocation positions of the image, audio data, and control data mapped to the frequency space, and then the frequency domain order of the data mapped to the time space. A baseband physical channel former for changing the baseband to form a baseband physical channel; A frequency band limiter for converting a signal output from the baseband physical channel former to an analog signal and then limiting a baseband frequency band to the converted signal; And a high frequency converter configured to convert the signal output from the frequency band limiter into a high frequency analog signal to be output to the air.

In addition, the baseband physical channel formation method according to an aspect of the present invention, in the baseband physical channel formation method in an orthogonal frequency division multiple access (OFDMA) wireless communication system, a) pilot according to a control command received from a higher layer Creating a control channel comprising a channel; b) modulating data related to an image or an audio received from the upper layer to multiple levels, and then controlling gains for each channel by data modulated to the multiple levels and control data about the generated control channel; c) after combining the gain adjusted data, mapping the combined data into frequency space; d) performing time-space mapping by converting time-specific allocation positions of the image, audio data, and control data mapped to the frequency space; And e) changing the frequency domain order of the data mapped to the time space to form a baseband physical channel, and then converting the data mapped to the frequency space into a frame of the time domain that can be loaded on the formed physical channel for transmission. It includes the steps to make.

In this case, step b) may include: generating an address of data to be read in a dual port memory storing data received from the upper layer; Reading data stored at the generated address from the dual port memory; And modulating the read data to multiple levels using at least one of quadrature phase shift keying (QPSK), 16 quadrature amplitude modulation (QAM), and 64 quadrature amplitude modulation (QAM).

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

2 is an internal configuration diagram of an OFDMA wireless communication system according to an embodiment of the present invention.

As shown in FIG. 2, an OFDMA wireless communication system according to an embodiment of the present invention includes an upper layer interface 200, a processor controller 210, a dual port memory 220, a baseband physical channel former 230, and an analog conversion. Frequency band limiter 240 and high frequency converter 250.

In more detail, first, the upper layer interface 200 receives a large amount of data such as video and audio according to a service type from an upper layer (eg, L2, L3 layer, and L1 control unit), and interfaces with higher layers. In charge of.

The processor controller 210 is in charge of the total control of the OFDMA wireless communication system that loads data on multiple carriers, and receives a large amount of data, a data processing method, and a physical channel frame format from an upper layer through the upper layer interface 200. . The processor controller 210 processes and controls data according to a processing method indicated by a higher layer.

The dual port memory 220 stores data processed by the processor controller 210.

The baseband physical channel forming apparatus 230 allocates the processed data to form a physical channel frame by allocating time and frequency space according to a channel type control command according to a service type or a physical environment indicated by the processor controller 210.

The analog conversion and frequency band limiter 240 converts the formed physical channel frame into an analog signal, and then limits the frequency band of the converted analog signal.

The high frequency converter 250 converts an analog signal of limited frequency band into a high frequency wave.

The antenna 260 transmits a high frequency analog signal output from the high frequency converter 250 to the air.

FIG. 3 is a detailed internal configuration diagram of the baseband physical channel forming apparatus shown in FIG. 2.

As shown in FIG. 3, the baseband physical channel former 230, that is, the baseband physical channel former, illustrated in FIG. 2 includes a processor interface 300, a dual port memory interface 310, and a control channel generator 320. , Multi-level modulator 330, channel-specific gain adjuster 340, resource space mapper 350, logical space mapper 360, time frequency converter 370, data mixer 380, high-speed inverse Fourier transform unit 390, the protection section insertion unit 400 and the gain control unit 410.

In detail, first, the processor interface 300 is responsible for the interface with the processor controller 210, and the dual port memory interface 310 is responsible for the interface with the dual port memory 200.

The control channel generator 320 generates a control channel such as a pilot channel according to a control command received from an upper layer, and the multi-level modulator 330 processes the data processed by the processor controller 210. Mapping to multiple levels

The gain controller 340 for each channel adjusts gain for each channel according to control information received from a higher layer, that is, data mapped to multiple levels and control channels generated by the control channel generator 320, that is, control data.

The resource space mapping unit 350 combines the gain-adjusted data and then maps the combined data to frequency space to transmit the combined data through a plurality of carriers having mutual orthogonality.

The logical space mapping unit 360 performs time-space mapping for converting the time-assigned positions of video and audio data and control data mapped in the frequency space.

The time frequency converter 370 changes the frequency domain order of the control data mapped in the time space to adjust the data order output after the fast inverse Fourier transform. That is, in the embodiment of the present invention, to form a subcarrier between -9.381 MHz and +9.381 MHz, that is, a baseband physical channel, the time frequency converter 370 has 1536 subcarriers ranging from DC to 18.76220703Mhz. After dividing into blocks, switch the frequency domain of the two divided blocks.

The data mixer 380 generates an m-sequence (typical m-sequence) such that the data values received from the upper layer have a random distribution in order to minimize the ratio between the output maximum value of the baseband physical channel former 230 and the output average value. Multiply and change data values.

The fast inverse Fourier transform unit 390 performs a fast inverse Fourier transform that converts a data frame in a frequency domain output from the data mixer 380 into a data frame in a time domain loaded on a multicarrier.

The guard interval inserter 400 inserts a guard interval that reduces the interference between the transmission symbols and the interference between the carriers in a frame of a time domain formed through a fast inverse Fourier transform, and the gain control unit 410 transmits a signal to be transmitted to a lower layer. Adjust the gain for power control.

FIG. 4 is a diagram illustrating in detail an internal configuration of the control channel generating unit shown in FIG. 3.

As shown in FIG. 4, the control channel generator 320 includes a timer / timer interface 410, a control channel data generator 420, and a control channel generator m-sequence generator 430.

In detail, the timer / timer interface 410 generates time information for each function unit of the physical channel forming apparatus to start or end an operation. That is, the timer / timer interface 400 informs the control channel generator 320 of time information regarding the operation control of the control channel generator 320.

The control channel data generator 420 receives data necessary to form a control channel (for example, data specifying pilot intervals and numbers) from the processor controller 210 according to the time information on which the timer has occurred, orthogonal amplitude modulation ( QAM) to generate a control channel, that is, control data.

The control channel generation m-sequence generator 430 generates an m-sequence necessary for generating the control channel and provides the generated m-sequence to the control channel data generator 420.

FIG. 5 is a diagram illustrating an internal configuration of the multilevel modulator shown in FIG. 3.

As shown in FIG. 5, the multilevel modulator 330 includes a dual port memory address generator 510, a multilevel modulation mapping unit 520, and a combiner 530.

In detail, the dual port memory address generator 510 first generates an address of processed data to be read from the dual port memory 220, and inputs the generated address to the dual port memory interface 310 to perform multilevel modulation. It can be delivered to the mapping unit 520.

Then, the multilevel modulation mapping unit 520 reads the data stored in the forwarded address from the dual port memory 220, and then reads the read data into multiple levels, that is, quadrature phase shift modulation (QPSK) and 16 quadrature amplitude. Map to one of modulation (QAM) and 64 quadrature amplitude modulation (QAM).

As such, the baseband physical channel forming apparatus according to an embodiment of the present invention supports various types of mapping schemes so that a user can variably control and transmit data in a limited channel space.

The combiner 530 combines the mapped data received from the multi-level modulation mapping unit 520 and the control data received from the channel generator 320 to form a frame.

Next, FIG. 6 is a diagram illustrating an internal configuration of the resource space mapping unit shown in FIG. 3.

As shown in FIG. 6, the resource space mapping unit 350 includes a timer interface 610, a dual port memory address generator 620, and a dual port memory 630.

In detail, the dual port memory address generator 620 receives timing information for each channel from the timer interface 610, and requires a cell for allocating resource space for each channel from the processor controller 210 through the processor interface 300. Receive control information including the number, cell group number, and the like.

The dual port memory address generator 620 calculates a position at which data should be mapped to the dual port memory 630 serving as a resource space in frequency and time space according to the received control information, and then calculates the calculated address. Is output to the dual port memory 630.

The dual port memory 630 stores data received from the gain control unit 340 for each channel at an address calculated by the dual port memory address generator 620. To this end, the dual port memory 630 controls the time space in time through timing controlled by the timer interface 610, and gain-adjusted data to an appropriate memory address according to the control information received from the processor controller 210. Perform spatial mapping to map.

Next, FIG. 7 is a diagram illustrating an internal configuration of the logical space mapping unit shown in FIG. 3.

As shown in FIG. 7, the logical space mapping unit 360 includes a timer interface 710, a dual port memory address generator 720, and a dual port memory 730.

In detail, the dual port memory address generator 720 receives timing information for each channel from the timer interface 710 in the same manner as the resource space mapping unit 350, and the processor controller 210 through the processor interface 300. Receive control information required for logical space allocation.

The dual port memory address generator 720 moves the data packet mapped to the resource space to the data space and the control channel space according to the received information. This is to more accurately compensate the pilot upon reception by distributing the pilot signal included in the control channel in an appropriate position in the packet.

That is, the dual port memory address generator 720 calculates a position to which data of each channel should be mapped so that a control channel and a data channel can be properly distributed in a logical space, and then calculates the calculated address of the dual port memory 730. Will output

The dual port memory 730 classifies the control channel and the data channel according to the timing information output from the timer interface 710 and maps the positions of the control channel and a part of the data channel to each other according to the control information received from the upper layer. By doing logical space mapping.

As such, the baseband physical channel forming apparatus and its method according to an embodiment of the present invention and the OFDMA wireless communication system including the same are various mapping methods (QPSK, 16QAM and 64QAM, etc.) to support various services according to the OFDMA scheme. Support. Through this, the present invention allows the user to variably (increase) the amount of data to be transmitted in the same channel environment.

Next, an operation process of the baseband physical channel forming apparatus according to an embodiment of the present invention will be described. FIG. 8 is a flowchart sequentially illustrating an operation process of the baseband physical channel forming apparatus illustrated in FIG. 3.

As shown in FIG. 8, the control channel generator 320 of the baseband physical channel forming apparatus first generates a control channel including a pilot channel according to a control command received from an upper layer (S801). In addition, the multi-level modulator 330 maps the data (data related to video or audio) processed by the processor controller 210 to multiple levels (S802).

In detail, the multi-level modulator 330 generates an address of data to be read from the dual port memory 220 storing data received from an upper layer, and then, according to the generated address, the dual port memory 220. ) To read the data. Thereafter, the multi-level modulator 330 modulates the read data into multiple levels using at least one of quadrature phase shift keying (QPSK), 16 quadrature amplitude modulation (QAM), and 64 quadrature amplitude modulation.

Thereafter, the gain controller 340 for each channel adjusts gain for each channel according to control information received from a higher layer of data mapped to multiple levels and control channels generated by the control channel generator 320, that is, control data. (S803).

Thereafter, the resource space mapping unit 350 combines the gain-adjusted data and then maps the combined data to frequency space to transmit the combined data through a plurality of carriers having mutual orthogonality (S804).

Thereafter, the logical space mapping unit 360 performs time-space mapping for converting the time-specific allocation positions of the video and audio data and the control data mapped in the frequency space (S805).

Thereafter, the time frequency converter 370 changes the frequency domain order of the control data mapped to the time space in order to adjust the data order output after the fast inverse Fourier transform (S806). That is, in the embodiment of the present invention, in order to form a subcarrier between -9.381 MHz and +9.381 MHz, that is, a baseband physical channel, the time frequency converter 370 may divide a subcarrier ranging from DC to 18.76220703Mhz in two blocks. After dividing by, change the frequency domain of the two divided blocks.

The data mixer 380 then multiplies the m-sequence to multiply the data values so that the data values received from the upper layer have a random distribution in order to minimize the ratio of the output maximum value of the baseband physical channel former 230 to the output average value. Change (S807).

Thereafter, the fast inverse Fourier transform unit 390 performs a fast inverse Fourier transform that converts a data frame in the frequency domain output from the data mixer 380 into a data frame in a time domain loaded on a multicarrier (S808).

Subsequently, the guard interval inserting unit 400 inserts a guard interval that reduces the interference between the transmission symbols and the interference between the carriers in the frame of the time domain formed through the fast inverse Fourier transform (S809), and the gain control unit 410 is a lower portion. The gain is adjusted to control power of the signal to be transmitted to the layer (S810).

The drawings and detailed description of the invention are exemplary only, and are used for the purpose of illustrating the invention only, and are not intended to be limiting or to limit the scope of the invention described in the claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

The baseband physical channel forming apparatus and method and the OFDMA wireless communication system including the same support various mapping methods (QPSK, 16QAM, 64QAM, etc.) to support various services according to the OFDMA scheme. Through this, the present invention has the effect of allowing the user to adjust the amount of data (increase) in the same channel environment to transmit the variable.

Claims (12)

An apparatus for forming a baseband physical channel in an orthogonal frequency division multiple access (OFDMA) wireless communication system, A control channel generator for generating a control channel including a pilot channel according to a control command received from an upper layer; A multi-level modulator configured to read data related to video or audio from a dual port memory storing data received from the upper layer and to modulate the data to a multi-level; A channel-specific gain control unit configured to gain-adjust the multi-level modulated data and the control data regarding the generated control channel for each channel; A resource space mapping unit for combining the gain-adjusted data and then mapping the combined data to frequency space; A logical space mapping unit configured to perform time-space mapping by converting time-specific allocation positions of the image, audio data, and control data mapped to the frequency space; And A time frequency converter configured to change a frequency domain order of the data mapped to the time space to form a baseband physical channel Baseband physical channel forming apparatus of the OFDMA wireless communication system comprising a. According to claim 1, A data mixer for multiplying the data output from the time frequency converter by an appropriate sequence such that the data value received from the upper layer has a random distribution; A fast inverse Fourier transform unit for converting and outputting data output from the data mixer into frames in a time domain that can be loaded on the formed physical channel; A guard section inserting section for inserting a guard section into a frame of a time domain output from the fast inverse Fourier transform section; And Gain control unit for adjusting the gain for power control of the frame inserted with the guard period The baseband physical channel forming apparatus of the OFDMA wireless communication system further comprising. The method of claim 2, The control channel generator, A timer for generating and notifying a start time and an end time of each functional unit of the baseband physical channel forming apparatus; A control channel data generator configured to receive data necessary for forming the control channel from the upper layer and modulate a phase amplitude according to a start time informed by the timer to generate the control channel; And A control channel generation m-sequence generation unit which generates a sequence required for generating the control channel and provides the control channel data generation unit to the control channel data generator. Baseband physical channel forming apparatus of the OFDMA wireless communication system comprising a. The method of claim 2, The multi-level modulator, A dual port memory address generator for generating an address of data to be read from a dual port memory storing data received from the upper layer; And A multi-level modulation mapping unit configured to read data stored at the generated address from the dual port memory and then modulate the read data to multiple levels Baseband physical channel forming apparatus of the OFDMA wireless communication system comprising a. The method of claim 4, wherein The multi-level modulation mapping unit, Baseband physical channel forming apparatus of OFDMA wireless communication system, characterized in that the modulation is multi-level using at least one of quadrature phase shift keying (QPSK), 16 quadrature amplitude modulation (QAM) and 64 quadrature amplitude modulation (QAM). . The method of claim 4, wherein The resource space mapping unit, A dual port memory address generator configured to calculate a location to which the combined data should be mapped according to control information including a cell number and a cell group number necessary for allocation of resource space for each channel received from the upper layer; And Dual port memory for resource space to map the combined data by controlling the frequency space occupying the calculated position Baseband physical channel forming apparatus of the OFDMA wireless communication system comprising a. The method of claim 6, The logical space mapping unit, A dual port memory address generator configured to calculate a position at which data regarding a control channel and a data channel should be mapped among data mapped to the frequency space according to control information received from the upper layer; And Dual port memory for logical space in which the positions of the control channel and some of the data channels are mapped to the calculated position. Baseband physical channel forming apparatus of the OFDMA wireless communication system comprising a. A processor controller which processes and controls data relating to an image or an audio received from an upper layer; A dual port memory for storing the processed data; After the received data is mapped to the frequency space, the data related to the control channel among the data mapped to the frequency space is mapped to the time space, and then the frequency domain order of the data mapped to the time space is changed to the baseband physical channel. A baseband physical channel former forming a baseband; A frequency band limiter for converting a signal output from the baseband physical channel former to an analog signal and then limiting a baseband frequency band to the converted signal; And A high frequency converter for converting the signal output from the frequency band limiter into a high frequency analog signal to be sent to the air OFDMA wireless communication system comprising a. A method for forming a baseband physical channel in an orthogonal frequency division multiple access (OFDMA) wireless communication system, a) generating a control channel comprising a pilot channel according to a control command received from a higher layer; b) modulating data related to an image or an audio received from the upper layer to multiple levels, and then controlling gains for each channel by data modulated to the multiple levels and control data about the generated control channel; c) after combining the gain adjusted data, mapping the combined data into frequency space; d) performing time-space mapping by converting time-specific allocation positions of the image, audio data, and control data mapped to the frequency space; And e) change the frequency domain order of the data mapped to the time space to form a baseband physical channel, and then convert the data mapped to the frequency space into a frame of the time domain that can be loaded on the formed physical channel for transmission. Steps to ensure A baseband physical channel formation method of an OFDMA wireless communication system comprising a. The method of claim 9, Step b), Generating an address of data to be read in a dual port memory storing data received from the upper layer; Reading data stored at the generated address from the dual port memory; And Modulating the read data to multiple levels using at least one of quadrature phase shift keying (QPSK), 16 quadrature amplitude modulation (QAM), and 64 quadrature amplitude modulation (QAM); A baseband physical channel formation method of an OFDMA wireless communication system comprising a. The method of claim 9, Step c) is Receiving control information including a cell number and a cell group number necessary for allocating resource space for each channel from the upper layer; Calculating a position to which the combined data should be mapped according to the received control information; And Controlling the frequency space occupying the calculated position to map the combined data A baseband physical channel formation method of an OFDMA wireless communication system comprising a. The method of claim 9, Step c) is Calculating a position to which data regarding a control channel and a data channel should be mapped among data mapped to the frequency space according to control information received from the upper layer; Dividing the control channel and the data channel according to timing information output from a timer for generating start and end times for each functional unit; And Mapping the separated channels by swapping positions of some channels according to information received from the upper layer; A baseband physical channel formation method of an OFDMA wireless communication system comprising a.

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