WO2012130088A1

WO2012130088A1 - Ofdm-based data transmission method and transmission station

Info

Publication number: WO2012130088A1
Application number: PCT/CN2012/072872
Authority: WO
Inventors: 鲍东山; 曾勇波; 雷俊; 王竞; 姚惠娟; 闫志刚; 刘慎发
Original assignee: 北京新岸线无线技术有限公司
Priority date: 2011-03-25
Filing date: 2012-03-23
Publication date: 2012-10-04
Also published as: CN103227765A

Abstract

Disclosed is an OFDM-based data transmission method, applicable in short-to-mid range wireless communication system uplink data transmission. An available frequency band of a system is equally divided into N number of basic frequency sub-bands. The method comprises: a transmission station occupying M number of basic frequency sub-bands, modulating data to the M number of basic frequency sub-bands and transmitting the data; and a receiving station receiving within the range of N number of basic frequency sub-bands the data transmitted by one or multiple transmission stations, where M ≤ N, and both M and N are positive integers. The present invention also provides an OFDM-based data transmission system. By employing in combination an OFDM-based technology and the frequency sub-bands, the present invention allows for the transmission station and the receiving station in a wireless communication system to have different bandwidth configurations, thus allowing for employment of a lower configuration by the transmitting station to reduce hardware costs, and for employment of a higher configuration by the receiving station to improve efficiencies such as frequency spectrum utilization rate and throughput, also allowing for multiple user stations to communicate simultaneously with an access point.

Description

OFDM-based data transmission method and transmitting station

The application date of this application is March 25, 2011, and the application number is 201110074380.X. The invention name is the priority of a prior application of an OFDM-based data transmission method and system, and the application date is May 19, 2011. The application number is 201110130194.3, the invention name is the priority of a prior application of a communication system, and the application date is August 11, 2011, and the application number is 201110230269.5, and the invention name is an OFDM-based data transmission method and The prior application priority of the system, and the application date is February 8, 2012, the application number is 201210027883.6, and the invention name is the priority of the prior application of an OFDM-based data transmission method and system, and the application date is The application number is 201210057448.8, the name of which is an OFDM-based data transmission method and the priority of the prior application of the transmitting station, the entire contents of which are hereby incorporated by reference.

Technical field

The present invention relates to the field of wireless communication technologies, and in particular, to an OFDM-based data transmission method and system.

Background technique

In the WLAN technology based on the 802.11 series of standards, multi-user transmission is implemented by Carrier Sense Multiple Access (CSMA), that is, multiple stations (STAs) cannot simultaneously access the access point (CAP). It can only be accessed in a time-sharing manner, even if the CAP has an idle frequency resource, the STA cannot use it. For example, in an 802.11n system, the CAP can occupy 40MHz bandwidth resources and can be divided into two 20MHz subbands. The STA can only communicate with the CAP by using the entire 40MHz bandwidth or one of the 20MHz subbands, but two STAs supporting 20MHz bandwidth. It is not possible to separately occupy one of the 20MHz sub-bands to communicate with the CAP at the same time. It can only communicate with the CAP with the primary channel in the 40MHz bandwidth in different time periods, and the 20MHz slave channel is idle, which causes the waste of the resources.

Orthogonal Frequency Division Multiple Access (OFDMA) is a multiple access method used in mobile communication systems. Multiple mobile terminals (MSs) occupy different subcarrier groups and base stations in the available bandwidth. BS) Simultaneous communication improves spectrum utilization.

In the existing WLAN, STA and CAP must use the same bandwidth configuration when communicating with the CAP. For example, in an 802.1 In system, STA and CAP communicate with either 40MHz bandwidth or 20MHz bandwidth. In the WLAN network, the CAP supports 40MHz bandwidth. There are two 20MHz STAs. The CAP can only use the 20MHz bandwidth configuration to communicate with the STAs that compete for the primary channel resources, thus causing 20MHz spectrum resources to be wasted. In future wireless LAN technologies, the available bandwidth of CAP may reach 80MHz or more, if the above bandwidth is continued The configuration scheme will result in more waste of spectrum resources.

In the OFDMA mechanism, although multiple terminals can occupy different subcarriers and simultaneously communicate with the base station, the receiving end and the transmitting end need to support the same bandwidth configuration, that is, the transmitting end inverse fast Fourier transform

(IFFT, Inverse Fast Fourier Transform) Modules must be identical in the FFT (Fast Fourier Transform) module. In addition, the uplink orthogonal frequency division multiple access (OFDM) access OFDMA multiple access method has higher synchronization requirements. In the time domain, multiple mobile terminals

(MS) The transmitted signal needs to arrive at the base station (BS) at the same time without causing inter-symbol interference and inter-user interference; in the frequency domain, due to the different carrier crystal frequency accuracy of multiple MS transmitters, and the BS carrier crystal frequency The deviation is also different, so the frequency offset of the signals arriving at each MS of the BS is also different, and the OFDM modulation itself is sensitive to the frequency offset, and the frequency offset from each MS signal must be corrected to correctly demodulate, otherwise it will cause multiple users. especially. Therefore, in an OFDMA system, time synchronization and frequency synchronization are key issues that require complex synchronization algorithms. In a wireless local area network system, if multiple access methods using OFDMA are used to increase spectral efficiency, equipment costs will increase.

Summary of the invention

The invention provides a data transmission method and a transmitting station based on Orthogonal Frequency Division Multiplexing (OFDM), which can realize multiple communication stations simultaneously communicating with a receiving station, and has low complexity, which can improve spectrum utilization rate and system throughput rate. In order to solve the above technical problem, the present invention proposes an OFDM-based data transmission method, including:

The transmitting station occupies M basic sub-bands, and modulates data to the M basic sub-bands for transmission;

The receiving station receives data transmitted from one or more transmitting stations within N basic subbands;

M<N, M, and N are positive integers.

In order to solve the above technical problem, the present invention further provides a transmitting station, including: a configuration module, configured to store information of M basic sub-bands that the transmitting station is allowed to occupy: M<N, N is a basic sub-band occupied by the receiving station. The number, M, N are positive integers; the sending processing module is configured to modulate data to the M basic sub-bands for transmission. In order to solve the above technical problem, the present invention further provides a resource indication method, including: scheduling one or more subchannels;

Generating a control signaling, including a bitmap for indicating one or more subchannels to be scheduled; transmitting the control signaling. In order to solve the above technical problem, the present invention further provides a resource indication apparatus, including: a scheduling module, configured to schedule one or more subchannels;

And an encapsulating module, configured to generate a control signaling, including a bitmap for indicating one or more subchannels to be scheduled; and a sending module, configured to send the control signaling.

In order to solve the above technical problem, the present invention further provides a resource indication method, including: receiving a control signaling, parsing a bitmap for indicating a scheduled subchannel, and knowing one or more subchannels to be scheduled;

Information is passed on the scheduled one or more subchannels. In order to solve the above technical problem, the present invention further provides a resource indication device, including: a receiving module, configured to receive a control signaling,

a parsing module, configured to parse a bitmap in the control signaling for indicating a scheduled subchannel, to learn one or more subchannels to be scheduled, and a sending module, to transmit on the scheduled one or more subchannels information.

In order to solve the above technical problem, the present invention further provides a resource indication method, including: setting a bit group for indicating subchannel scheduling, wherein each bit corresponds to one subchannel; and is scheduled according to a result of subchannel scheduling One or more bits corresponding to one or more subchannels are set to a first value; the bit group is transmitted through a control signaling.

In order to solve the above technical problem, the present invention further provides a resource indication apparatus, including: a scheduling module, configured to set a bit group for indicating subchannel scheduling, wherein each bit corresponds to one subchannel; The one or more bits corresponding to the one or more subchannels to be scheduled are set to a first value according to the result of the subchannel scheduling, and the sending module is configured to send the bit group by using one control signaling.

In order to solve the above technical problem, the present invention further provides a resource indication method, including: receiving a control signaling;

Obtaining a bit group for indicating subchannel scheduling, where each bit corresponds to one subchannel; Determining, according to one or more bits set in the bit group as the first value, that the corresponding one or more subchannels are scheduled;

Information is passed on the scheduled one or more subchannels. In order to solve the above technical problem, the present invention further provides a resource indication apparatus, including: a receiving module, configured to receive a control signaling;

a parsing module, configured to obtain a bit group for indicating subchannel scheduling, where each bit corresponds to one subchannel; and the one or more bits set to the first value in the bit group are known Corresponding one or more subchannels are scheduled; a transmitting module, transmitting information on the scheduled one or more subchannels.

In summary, the technical solution provided by the present invention, based on the combination of OFDM technology and sub-band, allows different transmission configurations of the transmitting station STA and the receiving station CAP in the wireless communication system, and the transmitting station STA can reduce the configuration with a lower configuration. Hardware implementation costs, receiving site CAP can use higher configuration to improve efficiency: spectrum utilization, throughput, etc., and can achieve multiple STAs to communicate with the CAP at the same time. In addition, a guard band, that is, a virtual carrier, is added at the edge of the sub-band, which avoids interference between sub-bands, and each sub-band can be separately shaped and filtered, and the receiving end only needs to perform matched filtering on the entire frequency band, without multiple baseband receiving. The machine matches the filtering for different sub-bands; the cyclic prefix (CP) is extended to reduce the time synchronization requirement. The sampling rate of the baseband sample at the receiving end is N times the sampling rate of the basic subband sample, ensuring that the IFFT/FFT module of the N1 point is required only in the basic subband, and the IFFT/FFT module of the N2=N*N1 point is used by the receiving end. Multiple parallel N1 point IFFT/FFT modules are not required to demodulate information for each sub-band. In this way, the frequency utilization rate and the system throughput rate can be improved, and multiple STAs can be simultaneously communicated with the CAP without increasing the cost of the system and the user site equipment.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a flowchart of a data transmission method based on OFDM according to an embodiment of the present invention; FIG. 2 is a schematic diagram of a wireless communication system architecture in the prior art; FIG. 3 is a multi-band OFDM transmitting end and a receiving end according to an embodiment of the present invention; Block diagram of the baseband part module;

4(a), (b), (c) and (d) are respectively schematic diagrams of several sub-band divisions in the embodiment of the present invention; FIGS. 5(a) and 5(b) are further in FIG. 4(b) Schematic diagram of two sub-band divisions;

6 is a block diagram of a transmitting station according to an embodiment of the present invention; FIG. 7 is a block diagram of a transmitting apparatus for resource indication according to an embodiment of the present invention; FIG. 8 is a block diagram of a receiving apparatus for resource indication according to an embodiment of the present invention; FIG.

FIG. 9 is a block diagram of another apparatus for transmitting a resource indication according to an embodiment of the present invention; FIG. 10 is a block diagram of another apparatus for receiving a resource indication according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION In view of the deficiencies in the prior art, the present invention proposes a multi-user data transmission scheme for medium and short-range wireless communication, using a multi-user access method similar to orthogonal frequency division multiple access OFDMA, based on OFDM And the corresponding synchronization mechanism, the available frequency band of the system is equally divided into N basic sub-bands (also called sub-channels), and the bandwidth of the transmitting end (ie, STA) transceiver may be a basic sub-band or a sub-band combined frequency band, and according to Specifically, the receiving station (ie, CAP) transceiver bandwidth may be N basic sub-bands. Assume that the basic sub-band is 20 MHz, and the receiving station transceiver bandwidth can be 20 MHz, 40 MHz, 80 MHz, that is, for STA receivers that only support 20 MHz bandwidth, the CAP signal of 80 MHz bandwidth can also be transmitted and received. Thus, the present invention is based on OFDM. The modulation technique enables multiple STAs to communicate with the CAP using different sub-band resources, and reduces the time-frequency synchronization requirements and synchronization accuracy required for the OFDMA system.

The invention provides an OFDM-based data transmission method, which is used for uplink data transmission in a medium-and short-range wireless communication system, and divides the available frequency band of the system into N basic sub-bands, as shown in FIG. 1 , the method includes:

Step S101: The transmitting station occupies M basic sub-bands, and modulates data to the M basic sub-bands for transmission. Step S102: The receiving station receives the transmission from one or more transmitting stations in the N basic sub-bands. The data coming.

Where M≤N, M, and N are positive integers.

Thereafter, the receiving station obtains data transmitted by each transmitting station by performing frequency domain signal separation on the received data.

The transmitting station supports at least the bandwidth of the M basic sub-bands; the receiving station supports at least the bandwidth of the N basic sub-bands. For example, STAs that support 80MHz bandwidth can transmit data at 20MHz, 40MHz, or 80MHz. Similarly, CAPs that support 80MHz bandwidth can also receive data in the 20MHz, 40MHz or 80MHz range. The above parameter configuration is implemented by the Medium Access Control Layer (MAC) layer, and the value of M can be configured by the CAP according to the bandwidth capability and the allocatable resources supported by the STA. The value of N is configured by the CAP according to the needs of the bandwidth resource. In a specific implementation, the STA may send a resource request to the CAP, where the resource request carries the bandwidth capability supported by the STA, and the CAP configures the STA according to the bandwidth capability supported by the STA and the currently assignable resource. The sub-band and carrying the basic sub-band information for the STA to the STA by sending a response message. The STA may encapsulate the resource request into an independent resource request frame, and initiate a resource request to the CAP in a competitive manner; When a data frame is transmitted upstream, a resource request is sent to the CAP along with the data frame. In addition, the CAP may also allocate uplink transmission resources to the STA in a polling manner. Preferably, the transmitting station may send the resource request on a basic sub-band to improve transmission resource utilization.

The embodiment of the present invention provides a resource indication method, where the CAP schedules transmission resources for the STA, and specifically includes: Step 1: scheduling one or more subchannels;

Step 2: Generate a control signaling, including a bitmap for indicating one or more subchannels to be scheduled; Step 3: Send the control signaling. The subchannel may be one subcarrier in the carrier aggregation system, or may be one subchannel (also referred to as a basic subband) in the spectrum aggregation system. The resource indication method is applicable to both the uplink resource indication and the downlink resource indication. Correspondingly, the embodiment of the present invention further provides a resource indication method, where the STA identifies the resource indication, and the data is transmitted on the scheduled resource, which specifically includes:

Step 1: Receive a control signaling, parse a bitmap in which the scheduled subchannel is indicated, and learn one or more subchannels that are scheduled;

Step 2: Pass information on the scheduled one or more subchannels. The resource indication method is applicable to both the uplink resource indication and the downlink resource indication. In conjunction with the STA uplink transmission of the present invention: the CAP schedules transmission resources for one or more STAs, and for any one of the STAs: the CAP generates a control signaling according to the M basic sub-bands scheduled for the STA, including a bitmap bitmap of M basic subbands scheduled for the STA; transmitting the control signaling. After receiving the control signaling, the corresponding STA parses the bitmap for indicating the scheduled basic sub-band, and knows the M basic sub-bands scheduled for it; and transmits the M basic sub-bands for which it is scheduled. data. An embodiment of the present invention further provides another resource indication method, including:

Step 1: setting a bit group for indicating subchannel scheduling, where each bit corresponds to one subchannel;

Step 2: Set one or more bits corresponding to one or more scheduled subchannels to a first value according to the result of the subchannel scheduling. Step 3: Send the bit group by using one control signaling. The subchannel may be one subcarrier in the carrier aggregation system, or may be one subchannel in the spectrum aggregation system. Correspondingly, the embodiment of the present invention further provides a resource indication method, where the STA identifies the resource indication, and the data is transmitted on the scheduled resource, which specifically includes:

Step 1: Receive a control signaling;

Step 2: Obtain a bit group for indicating subchannel scheduling, where each bit corresponds to one subchannel;

Step 3: According to one or more bits in the bit group set to the first value, the corresponding one or more subchannels are scheduled; Step 4: in the scheduled one or more subchannels Pass the information on. The resource indication method is applicable to both the uplink resource indication and the downlink resource indication. In combination with the STA uplink transmission of the present invention: the CAP presets a bit group for indicating basic sub-band scheduling, wherein each bit corresponds to one basic sub-band; the CAP schedules transmission resources for one or more STAs, for any STA The CAP sets the M bits corresponding to the scheduled M basic sub-bands to the first value according to the M basic sub-bands scheduled for the STA, and sends the bit group by using one control signaling. After receiving the control signaling, the corresponding STA obtains a bit group for indicating basic sub-band scheduling, and learns the corresponding M basics according to the M bits set to the first value in the bit group. The sub-bands are scheduled; information is passed on the scheduled M basic sub-bands.

To further illustrate the resource allocation indication scheme provided by the present invention, a specific uplink and downlink scheduling signaling field is provided herein for allocating uplink or downlink transmission resources, as shown in Table 1.

Table 1 Definition

Bit

DL UL b ₀ = Downstream scheduling 3⁄4 = 0, uplink scheduling

3⁄4 = 0, time-division resource scheduling 3⁄4 = 1, reserved

[b ₅ · · ], Bit Map indicates the effective 20MHz subchannel position of the scheduling signaling Indicate the current transmission mode

00: Open loop SU-MIMO transmission

01 : Closed-loop SU-MIMO transmission (dedicated demodulation pilot mode) ^b , K

10: Closed-loop MU-MIMO transmission (only valid when 1 = 1) 11 : Closed-loop SU-MIMO transmission (common demodulation pilot mode) User resource block starting OFDM symbol, field value: 1~ 511 codeword I MCS and parallel Number of spatial streams ( < 4 ) indicates (Appendix A) hh · · -h Number of consecutive OFDM symbols for user resource blocks, field value: 1~511 MCS of codeword II and parallel space

Interflow number indication

1111111, this transmission is

SU-MIMO codeless word II

1111110, this transfer is 2

Stream MU-MIMO liiiioi, this transfer is 3

Stream MU-MIMO b ₃₆ b ₃₅ · · · 3⁄4, BitMap indication

1111100, this transmission is 4 CQI, CSI, or BFM feedback sub-stream MU-MIMO channel

κ ··· 1111011, this transmission is 5

b _{39 8 7} , for CSI feedback, flow MU-MIMO

Indicates the number of rows of the feedback matrix; for liiioio, this transmission is 6 BFM feedback, indicating the column flow of the feedback matrix MU-MIMO number

1111001, this transfer is 7

Stream MU-MIMO liiiooo, this transmission is 8

Stream MU-MIMO

0000000 - 1100011 ,

MCS of SU-MIMO codeword II and

Number of streams . =1, request CQI feedback

3⁄4Αι=οι, request CSI feedback

SU-MIMO: 000

MU-MIMO: spatial stream start

3⁄4Αι =ιο, request BFM reverse position index, field value 0~7

Feed Α=ιι, reserve

00, BCC code

01, LDPC code length 1 (1344 bits) 10, LDPC code length 2 (2688 bits) 11, LDPC code length 3 (5376 bits)

0, time domain demodulation pilot period 1 (long demodulation pilot period)

1, time domain demodulation pilot period 2 (short demodulation pilot period)

00, frequency domain demodulation pilot pattern 1 ( DPI = 1 )

01, Frequency domain demodulation pilot pattern 2 ( DPI=2 ) 10, frequency i or demodulation pilot pattern 3 (DPI=4)

11, reserved

3⁄4 ₈ =0, ... ₉ indicates resources for signaling and feedback transmission b _c , b •••b in the user resource block, domain values 0 to 63

54 53 48 8=1, ·· ₉ reserved

0, do not use STBC transmission

1, ST use STBC transmission b~n t> ₁₀ ... ₅ 6 CRC calibration protection and STAID identification Wherein, b5b4b3b2 is used to indicate a 20 MHz subchannel position that is valid for the scheduling signaling. =丄 indicates that this schedule is valid for subchannel 0, otherwise it is invalid. ^{= 1} indicates that this schedule is valid for subchannel 1, otherwise it is invalid. ^{3⁄44 = 1} indicates that this schedule is valid for subchannel 2, otherwise it is invalid. ^{3⁄45 = 1} indicates that this schedule is valid for subchannel 3, otherwise it is invalid. The embodiment of the present invention provides a resource allocation method for carrier aggregation, which uses a bitmap to indicate which component carrier the resource allocation indication applies to in the resource allocation indication signaling, saves control signaling overhead, and reduces control. Signaling detection complexity.

The implementation of the present invention to allow STAs with different bandwidth capabilities to communicate with the CAP will be described in detail below.

The transmitting station may separately modulate data onto the M basic sub-bands and transmit independently on each basic sub-band. The transmitting station may also modulate data onto a frequency band of the M basic sub-band combinations for transmission over the combined frequency band. The M basic sub-bands are consecutive basic sub-bands. Preferably, multiple transmitting stations may share the same basic sub-band in a space division multiplexing manner. In the data transmission method provided by the embodiment of the present invention, when a plurality of transmitting stations transmit data, a carrier frequency offset is respectively set for each transmitting station to determine a carrier center frequency of each transmitting station. That is, the transmitting station can modulate data on the M basic sub-bands to a designated radio frequency band by spectrum shifting. Correspondingly, the receiving station receives data of the corresponding transmitting station on the corresponding radio frequency band. In the data transmission method provided by the present invention, the baseband portion is processed by an inverse fast Fourier transform IFFT/fast Fourier transform FFT, and the receiving station uses a different FFT length from the transmitting station: if the basic subband uses K point IFFT/FFT module, if the transmitting station occupies M basic sub-bands, the length of the IFFT/FFT module of the transmitting station is M*K point, and the length of the IFFT/FFT module of the receiving station is N*K point. That is, the transmitting station performs IFFT processing on the data length M*K point before performing spectrum shifting; the receiving station performs length N*K on data received in the N basic sub-bands. Point FFT processing. Where K represents the number of subcarriers contained in one basic subband.

When the transmitting station performs IFFT processing, the sampling rate of the sample used is M*fs; when the receiving station performs FFT processing, the sampling rate of the sample used is N*fs. Fs represents the input sample sampling rate of the IFFT/FFT corresponding to a basic subband. If the transmitting station and the receiving station support the same bandwidth, the number of IFFT/FFT subcarriers and the sampling rate of the transmitting station and the receiving station are the same. If there are multiple transmitting sites in the system, each transmitting site supports different bandwidths. Under the premise of meeting the bandwidth configuration requirements, multiple transmitting sites can send data to the receiving site with their respective bandwidth configurations within the bandwidth supported by the receiving site. The transmitting station only needs to perform shaping filtering processing on the data in the M basic sub-bands before performing the spectrum shifting. The receiving station may perform matching filtering processing on the data received in the N basic sub-bands before performing the FFT processing.

Preferably, a guard band can be set at the edge of the sub-band to reduce filtering requirements and reduce interference between users. Virtual subcarriers can be placed at both ends of each subband. Preferably, virtual subcarriers may also be provided at both ends of the combined frequency band. In the data transmission method provided by the embodiment of the present invention, when a plurality of transmitting stations transmit data, setting a cyclic prefix CP length T _{CP of} the wireless communication system satisfies the following conditions:

Where 2 δ is the two-way propagation delay experienced by the signal from the transmitting station to the maximum allowable coverage radius, multipath delay spread. Preferably, in the embodiment of the present invention, the subband broadband may be 20 MHz; and/or M=l, 2, 4; and/or K=256; and/or the baseband sample sampling rate fs=20 MHz. Preferably, the value of M can be, M=2 ⁿ , and n is a natural number. Preferably, the value of n can be n=0, 1 or 2.

In order to make the principles, features, and advantages of the present invention more comprehensible, the present invention will be described in detail with reference to the specific embodiments.

2 is a schematic block diagram of a transmitting end and a receiving end. The embodiment of the present invention relates to only a part of the baseband in the transmitting end and the receiving end. Therefore, the source, the radio frequency, the sink, and the baseband part shown in FIG. 2 are not involved in the present invention. The module is not mentioned here. First, the entire frequency band of the system is equally divided into N basic sub-bands for use by STA stations in the system.

In this embodiment, the entire bandwidth of the system is W=80 MHz, which is equally divided into N=4 basic sub-bands, each basic sub-band bandwidth B=20 MHz, assuming that each basic sub-band can only be used by one transmitting station STA. Separately occupied, and one STA can transmit data to the CAP using one or more basic sub-bands. STA supports 20MHz, 40MHz and 80MHz bandwidth. CAP supports 20MHz, 40MHz and 80MHz bandwidth. When CAP has 80MHz bandwidth receiving capability, it can receive data transmitted in any subband combination at the same time. Figure 3 shows the block diagram of the baseband part of the four 20MHz bandwidth stations STA1 ~ STA4 occupying different subbands to transmit data to an 80MHz bandwidth CAP.

As shown in FIG. 3, four STAs transmit data to the CAP, which is represented by STA1 to STA4. Each STA occupies a basic sub-band, that is, a 20 MHz bandwidth, and XI to X4 represent data from the corresponding STA. Only the module closely related to IFFT/FFT when implementing multi-band OFDM transmission is shown in FIG. Other modules that do not involve or affect a complete transceiver, such as coding, constellation point mapping, stream parsing, channel estimation, MIMO detection, decoding, etc., are not described herein. The sub-band division in the embodiment of the present invention is as shown in FIG. 4(a). Figure 4 is a schematic diagram of the equivalent baseband of the subband division. For convenience, the negative frequency used in the 802.11n standard can be used as the phase difference; the frequency of the negative frequency is shifted to the positive frequency, but the two are not intrinsically difference. The CAP uses a bandwidth of 80 MHz in the [-40 MHz, 40 MHz] band, and the center frequency f0=0. Only the case of the STA single antenna is illustrated in FIG. 4, and the same applies to the case where the STA and the CAP are multi-antenna exclusive sub-bands and the plurality of STAs share the sub-band by space division multiplexing. Figure 4 (a) is a schematic diagram of the frequency bands occupied by the four STAs in Figure 3, where fO = 0, STAl uses the [-40MHz, - 20MHz] frequency band, the center frequency fl = -30MHz, and STA2 uses [-20MHz] , 0MHz] frequency band, center frequency £2=-10MHz, STA3 uses [0MHz, 20MHz] frequency band, center frequency B=10MHz, STA4 uses [20MHz, 40MHz] frequency band, center frequency f4=30MHz. The signal model of the sub-band division shown in Fig. 4(a) is described below. To transmit four 20MHz signals in parallel, each signal can be separated in the frequency domain to ensure orthogonality, that is, respectively modulated to non-overlapping frequency bands. The number of subcarriers Nfft (the number of points of the IFFT/FFT transform), the sample interval T _{s ,} and the correspondence between the sample frequencies f _s are as follows:

Tu represents the duration of the OFDM symbol. When the baseband signal center frequency is 0, and the subcarrier spacing is = 7S.\25 kHz, the number of subcarriers used in this embodiment Nfft (the number of IFFT/FFT transform points), the sample interval T _s, and the sampling frequency f _s The correspondence between them is shown in Table 1. Table 1

The sample frequency fs in Table 1 is the lowest sample rate, and the adjustable value is greater than the value shown in Table 1. In this embodiment, the center frequencies of the four signals are / -SOMHz, f ₂ = - 10MHz, / ₃ = 10MHz, / corpse 30MHz, which occupies a continuous 80MHz channel, and the subcarriers corresponding to the center frequency of each signal are biased. The value of the shift is '-: -384 A, -128 A, 128 A, 384 A. Referring to FIG. 3 and FIG. 4( a ), in this embodiment, the data of each STA first passes the IFFT transform of Nfftl=256 points (number of subcarriers), and the sampling interval of the baseband samples (the sampling interval of the input sample points of the IFFT module) ) is 50ns, then D/A (D/A part contains low-pass filtering), then spectrum shifting, the center frequency is fl ~ f4, where fl = fO-30, £2 = fO-10, S = fO +10, f4=fO+30, the unit is MHz, processed by other baseband modules, RF channel and channel are received by CAP. The data received by CAP is also processed by RF channel and other baseband modules, CAP baseband sample points. The sampling interval is 12.5 ns. After FFT conversion of Nfft2=1024 points, the data of different STAs can be taken out from the corresponding frequency band for subsequent processing. Regardless of time deviation, frequency deviation, and disturbance noise, it is assumed that the receiving baseband receives continuous signals of different carrier frequencies as follows: 127 127

^( =— { XW _k exp(y2^:(^-384)A + ∑ X _n Qxp(j2 (nm)AFt)

=-m n=-m

127 127

+ ∑ Y _k cxp(j2n(k + m)AFt) + ^ Ζ _η χρ '2π(η + 3M)AFt) k=- =-m

(1) For the signal, take

Γ 127 127

r{n)[ _=nT =− ^ W _k Qx _V (j2 (k -3M)AFnT _s )+ ^ X _n ex _V (j2 (n-l28)AFnT _s )

^{11 S} N [^=-128 π=-128

127 127

+ XY _k exp(j2 (k + \2S)AFnT _s )+ YZ _n exp(j^(n + 3S4)AFnT _s )

∑ W _k , _+3S4 Qxp(j2 k'AFnT _s )+ 3⁄4 X _n , _+m exp(j2nn' AFnT _s )

N

Y _r _ _l2g εχρ(72π/ ' AFnT _s ) + ^ Z _m , _ ₁₈₄ exp(j2Kin'AFnT _s )

(2) For a receiver with 80MHz bandwidth, N=1024, T, =^ =—^―, substituting the above formula:

N NAF

For r (n, 1024-point FFT transform can demodulate the signals W, X, Y, Ζ. To ensure that the signal period is consistent, the sampling rate of the FFT module input data is different for different bandwidth signals. Under the 20MHz bandwidth, 256-point FFT, the sampling period should be 50 ns; and in the 80 MHz bandwidth, the 1024-point FFT, the sampling period is 12.5 ns. In the embodiment of the present invention, the sub-bands are combined for use by each station, for example, two sub-frequency Band synthesis is used, or all subbands are combined into one band for use. The subband combination manner in this embodiment is as shown in FIG. 4(b), FIG. 4(C) and FIG. 4(d). Figure 4 (b) shows the subband division of two 20MHz bandwidth STAs with a 40MHz bandwidth STA sharing 80MHz frequency division. The center frequencies of the three subbands are fl=-30MHz, f2=0, B= 30MHz _{o In} addition, Figure 4(b) has two variants, as shown in Figure 5.

Figure 4(c) shows the subband division of the 80MHz spectrum shared by two 40MHz bandwidth STAs. The center frequencies of the two subbands are fl=-20MHz and £2=20MHz.

Figure 4(d) shows the subband division of all 80MHz spectrum for an 80MHz bandwidth STA. The subband center frequency is fl=0.

4(b) shows a case where two STAs of 20 MHz bandwidth share a frequency of 80 MHz with a STA of 40 MHz bandwidth, and the frequency band distribution can also be changed, as shown in FIG. 5.

When the CAP is configured for 40MHz or 80MHz bandwidth, it is allowed to have a free basic subband or a basic subband combination in its frequency.

If the transmitting station and the receiving station support the same bandwidth, the number of IFFT/FFT subcarriers and the sampling rate of the transmitting station STA and the receiving station are the same; if there are multiple transmitting stations in the system, the bandwidth supported by each transmitting station is different, Under the premise of meeting the bandwidth configuration requirements, multiple transmitting stations can send data to the receiving station with their respective bandwidth configurations within the bandwidth supported by the receiving station.

For example, if the available bandwidth of the system bandwidth is 40MHz, the CAP supports 40MHz, the STA supports 20MHz or 40MHz, and the CAP supports simultaneous transmission of two STAs. If the available bandwidth of the system is 20MHz, the frequency band can be further divided. Each STA uses a part of resources in the frequency band, but the center frequency of each STA is the same as that of the CAP, and no additional spectrum shift (center frequency offset) is performed. Each sub-band occupied by each STA has its own virtual sub-carrier, which is disposed at the edge (both ends) of the sub-band, and is used as a guard band. Each STA only has to do the shaping filtering on the bandwidth it supports, rather than the shaping filter on the entire W. The CAP is shaped filtering over the entire bandwidth W, so the CAP can flexibly support STAs with different bandwidth configurations. In order to eliminate or minimize the occurrence of Inter-Symbol Interference (ISI) and multi-user interference, a reasonable synchronization mechanism needs to be designed in the system, specifically, a cyclic prefix (CP, Cyclic Prefix) is introduced. The length of the cyclic prefix CP varies with the transmission mode, the frame structure, and the corresponding protocol, and it is necessary to design the length of the cyclic prefix CP in the system that satisfies the requirements. In the embodiment of the present invention, when receiving the downlink frame sent by the receiving station CAP, the transmitting station STA may determine a time point t according to the synchronization preamble of the downlink frame. Each STA calculates the uplink transmission time based on the estimated time points. The CP length in the design system ensures that the far-reaching STA to CAP bidirectional propagation delay 2<5 and multipath delay extension τ„, and then consider the time. Synchronization error, then all STA's multipath signals can reach the STA within the CP range, without inter-symbol interference (ISI) and multi-user interference. In the embodiment of the present invention, when there are multiple transmitting stations transmitting data, setting the cyclic prefix CP length T _{CP of} the wireless communication system needs to meet the following conditions:

An embodiment of the present invention further provides a transmitting site, as shown in FIG. 6, including:

The configuration module 61 is configured to store information about the M basic sub-bands that the transmitting station is allowed to occupy: M<N, N is the number of basic sub-bands occupied by the receiving station, and M and N are positive integers; the sending processing module 62, For transmitting data to the M basic sub-bands for transmission. The configuration information of the M basic sub-bands is configured for the receiving station. Preferably, the configuration module 61 is further configured to store a bandwidth configuration that the transmitting station can support, which is greater than or equal to the bandwidth of the M basic sub-bands. Preferably, the configuration module 61 is further configured to receive control signaling, parse a bitmap in the control signaling for indicating a scheduled basic sub-band, and learn one or more basic sub-bands that are scheduled, And sending a scheduling instruction to the sending processing module 62. The sending processing module 62 is configured to transmit data on the scheduled one or more basic sub-bands according to the scheduling instruction.

Preferably, the configuration module 61 is further configured to receive control signaling, obtain a bit group for indicating basic sub-band scheduling, where each bit corresponds to a basic sub-band; and is set according to the bit group Obtaining, for one or more bits of the first value, that the corresponding one or more basic sub-bands are scheduled, and sending a scheduling instruction to the sending processing module 62; the sending processing module 62, configured to perform, according to the scheduling An instruction to pass data on the scheduled one or more basic sub-bands.

Preferably, the sending processing module 62 can separately modulate data into the M basic sub-bands and transmit independently on each basic sub-band. Preferably, the transmission processing module 62 may also modulate data into frequency bands of the M basic subband combinations and transmit the frequency bands in the combined frequency bands. Preferably, the M basic sub-bands are continuous basic sub-bands.

Preferably, the sending processing module 62 can share the same basic sub-band with other transmitting stations by means of space division multiplexing.

Preferably, the sending processing module 62 includes: a frequency shifting unit 624, configured to modulate data on the M basic subbands to a specified radio frequency band by frequency shifting.

Preferably, the sending processing module 62 further includes:

An IFFT processing unit 622 having a length of M*K is used to perform IFFT processing on the data and output to the frequency shifting unit 624. Where K represents the number of subcarriers contained in one basic subband.

Preferably, the input sample sampling rate of the IFFT processing unit 622 is M*fs. Fs representation The input sample sampling rate of the IFFT/FFT corresponding to a basic subband.

Preferably, the sending processing module 62 further includes: a filtering processing unit 623, configured to perform shaping filtering processing on the IFFT processed data, and output the data to the spectral H-shift unit 624. Preferably, the sending processing module 62 includes:

The subcarrier generation unit 621 can set a guard band at the edges of the respective subbands by setting virtual subcarriers at both ends of each subband. The illustrated subcarrier generating unit 621 may also set virtual subcarriers at both ends of the frequency band combined by the M basic subbands to set virtual subcarriers at both ends of the combined frequency band.

Preferably, the basic sub-band has a bandwidth of 20 MHz. Preferably, K = 256.

Preferably, fs = 20 MHz. Preferably, M = 2n, n is a natural number. Preferably, n = 0, 1 or 2.

The embodiment of the invention also provides an OFDM-based data transmission system. The system can be used for medium to short range wireless communication, and the available frequency band of the system is equally divided into N basic sub-bands. The system includes: a transmitting station as described above and a receiving station for receiving data transmitted from one or more transmitting stations within N basic sub-bands. If there are multiple transmitting sites in the system, each transmitting site supports different bandwidths. Under the premise of meeting the bandwidth configuration requirements, multiple transmitting sites can send data to the receiving site with their respective bandwidth configurations within the bandwidth supported by the receiving site.

The embodiment of the present invention further provides a sending device for resource indication, as shown in FIG. 7, including: a scheduling module 701, configured to schedule one or more subchannels;

The encapsulating module 702 is configured to be connected to the scheduling module 701, and configured to generate, according to the one or more subchannels that are scheduled, a control signaling, where a bitmap is used to indicate one or more subchannels that are scheduled, and a sending module 703, Connected to the encapsulating module 702, configured to send the control signaling. The subchannel may be one subcarrier in the carrier aggregation system or one subchannel in the spectrum aggregation system. The resource indication may be an indication of an uplink resource, or may be an indication of a downlink resource.

The embodiment of the invention further provides a receiving device for the resource indication, which is used in combination with the resource indicating device to receive the resource indication, and includes: The receiving module 801 is configured to receive a control signaling.

The parsing module 802 is connected to the receiving module 801, configured to parse a bitmap in the control signaling for indicating a scheduled subchannel, to learn one or more subchannels to be scheduled, and a sending module 803, A parsing module 802 is coupled to communicate information on the scheduled one or more subchannels. The subchannel may be one subcarrier in the carrier aggregation system or one subchannel in the spectrum aggregation system. The resource indication may be an indication of an uplink resource, or may be an indication of a downlink resource.

The embodiment of the present invention further provides another resource indication sending apparatus. As shown in FIG. 9, the method includes: a scheduling module 901, configured to set a bit group for indicating subchannel scheduling, where each bit corresponds to one sub- The encapsulating module 902 is connected to the scheduling module 901, and configured to set one or more bits corresponding to the one or more subchannels to be the first value according to the result of the subchannel scheduling;

The sending module 903 is connected to the encapsulating module 902, and configured to send the bit group by using one control signaling. The subchannel may be one subcarrier in the carrier aggregation system, or may be one subchannel in the spectrum aggregation system. The resource indication may be an indication of an uplink resource, or may be an indication of a downlink resource.

The embodiment of the present invention further provides a receiving device for the resource indication, which is used in combination with the resource indicator device to receive a resource indication. As shown in FIG. 10, the method includes:

The receiving module 1001 is configured to receive a control signaling. The parsing module 1002 is connected to the receiving module 1001, and configured to parse the control signal to obtain a bit group for indicating subchannel scheduling, where each bit corresponds to a subchannel;

The sending module 1003 is connected to the parsing module 1002, and according to the one or more bits set to the first value in the bit group, the corresponding one or more subchannels are scheduled, and in the scheduled Information is passed on one or more subchannels.

The subchannel may be one subcarrier in the carrier aggregation system, or may be one subchannel in the spectrum aggregation system. The resource indication may be an indication of an uplink resource, or may be performed for a downlink resource. Instructions.

In summary, the technical solution provided by the present invention, based on the combination of OFDM technology and sub-band, allows different transmission configurations of the transmitting station STA and the receiving station CAP in the wireless communication system, and the transmitting station STA can reduce the configuration with a lower configuration. Hardware implementation costs, receiving site CAP can use higher configuration to improve efficiency: spectrum utilization, throughput, etc., and can achieve multiple STAs to communicate with the CAP at the same time. In addition, a guard band, that is, a virtual carrier, is added at the edge of the sub-band, which avoids interference between sub-bands, and each sub-band can be separately shaped and filtered, and the receiving end only needs to perform matched filtering on the entire frequency band, without multiple baseband receiving. The machine performs matched filtering for different sub-bands, and extends the cyclic prefix (CP) to reduce the time synchronization requirement. The sampling rate of the baseband sample at the receiving end is N times the sampling rate of the basic sub-band sample, ensuring that the IFFT/FFT module of the N1 point is required only in the basic sub-band, and the IFFT/FFT module of the N2=N*N1 point is used. Instead of multiple parallel N1 point IFFT/FFT modules, the information for each subband is demodulated. This not only improves the spectrum utilization system throughput rate, but also enables multiple STAs to communicate with the CAP at the same time without increasing the cost of the system and user site equipment.

The present invention has been disclosed in the above preferred embodiments, but it is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection should be determined by the scope defined by the claims of the present invention.

Claims

Claim

An OFDM-based data transmission method, characterized in that: a transmitting station occupies M basic sub-bands, and modulates data to the M basic sub-bands for transmission;

M<N, M, and N are positive integers.

2. The data transmission method according to claim 1, further comprising: said receiving station performing frequency domain signal separation on the received data to obtain data transmitted by each transmitting station.

3. The data transmission method according to claim 1, wherein: the bandwidth supported by the transmitting station is less than or equal to the bandwidth supported by the receiving station.

The data transmission method according to claim 1, wherein: the transmitting station receives control signaling, parses a bitmap bitmap for indicating a scheduled basic sub-band, and knows that the M basics are scheduled. Subband.

The data transmission method according to claim 4, further comprising: the receiving station scheduling M basic sub-bands for the transmitting station; generating a control signaling, where the indication is used to indicate one of the scheduled ones or a bitmap bitmap of a plurality of basic subbands; transmitting the control signaling.

The data transmission method according to claim 1, wherein: the transmitting station receives control signaling, and obtains a bit group for indicating basic sub-band scheduling, wherein each bit corresponds to a basic sub-band; According to the M bits set to the first value in the bit group, the corresponding M basic sub-bands are learned to be scheduled.

The data transmission method according to claim 6, further comprising: the receiving station setting, for the transmitting station, a bit group for indicating basic sub-band scheduling, wherein each bit corresponds to a basic sub-band And setting M bits corresponding to the M basic sub-bands to be the first value according to the result of the basic sub-band scheduling; and transmitting the bit group by using one control signaling.

8. The data transmission method according to claim 1, wherein:

The transmitting station separately modulates data onto the M basic sub-bands and transmits independently on each basic sub-band.

9. The data transmission method according to claim 1, wherein:

The transmitting station modulates data onto a frequency band of the M basic subband combinations for transmission on the combined frequency band.

10. The data transmission method according to claim 9, wherein: The M basic subbands are continuous basic subbands.

The data transmission method according to claim 1, wherein: the plurality of transmitting stations share the same basic sub-band in a manner of space division multiplexing.

The data transmission method according to claim 1, wherein: said transmitting station modulates data on said M basic sub-bands to a designated radio frequency band by spectrum shifting.

13. The data transmission method according to claim 12, wherein:

The transmitting station performs IFFT processing on the data length M*K point before performing the frequency shifting; the receiving station performs the length of the data received in the N basic sub-bands as N*K Point FFT processing;

Where K represents the number of subcarriers included in one basic subband.

The data transmission method according to claim 13, wherein: when the transmitting station performs IFFT processing, the sample sampling rate used is M*fs; when the receiving station performs FFT processing, The sampling rate of the sample is N*fs;

Fs represents the input sample sampling rate of the IFFT/FFT corresponding to a basic subband.

The data transmission method according to claim 13, wherein:

The transmitting station performs a shaping filtering process on the IFFT processed data before performing the spectrum H shift;

The receiving station performs a matching filtering process on the data received in the N basic sub-bands before performing the FFT processing.

The data transmission method according to claim 8, further comprising: setting a guard band at an edge of each sub-band, comprising:

Virtual subcarriers are disposed at both ends of each of the subbands.

The data transmission method according to claim 9, further comprising: setting a guard band at an edge of a frequency band of the M basic subband combinations, comprising: setting virtual at both ends of the combined frequency band Subcarrier.

The data transmission method according to claim 1, wherein the cyclic prefix CP length T _{CP of the system} satisfies the following conditions:

Where 2δ is the two-way propagation delay experienced by the signal from the transmitting station to the maximum allowable coverage radius, and τ _Μ is the multipath delay spread.

The data transmission method according to claim 1, wherein the basic sub-band has a bandwidth of 20 MHz.

The data transmission method according to claim 13, wherein K = 256.

The data transmission method according to claim 14, wherein fs = 20 MHz.

The data transmission method according to claim 1, wherein M = 2 ⁿ and n is a natural number.

The data transmission method according to claim 22, wherein n = 0, 1 or 2.

24. A transmitting station, comprising: a configuration module, configured to store information of M basic sub-bands allowed to be occupied by a transmitting station: M<N, N is a number of basic sub-bands occupied by the receiving station, M , N is a positive integer; a sending processing module, configured to modulate data to the M basic sub-bands for transmission.

The transmitting station according to claim 24, wherein: the configuration module is further configured to store a bandwidth configuration that the transmitting station can support, which is greater than or equal to a bandwidth of the M basic sub-bands.

The transmitting station according to claim 24, wherein: the configuration module is further configured to receive a control signaling, and parse a bitmap for indicating a scheduled basic sub-band in the control signaling, Know the M basic subbands that are scheduled.

The transmitting station according to claim 24, wherein: the configuration module is further configured to receive a control signaling, and obtain a bit group for indicating basic sub-band scheduling, where each bit corresponds to one The basic sub-band; knowing that the corresponding M basic sub-bands are scheduled according to the M bits set to the first value in the bit group.

The transmitting station according to claim 24, wherein: said transmitting processing module modulates data into said M basic sub-bands and transmits them independently on each of said basic sub-bands.

The transmitting station according to claim 24, wherein: said transmitting processing module modulates data onto a frequency band of said M basic subband combinations and transmits said frequency band.

30. The transmitting station of claim 29, wherein: said M basic sub-bands are consecutive basic sub-bands.

The transmitting station according to claim 24, wherein: the transmitting processing module shares the same basic sub-band with other transmitting stations by means of space division multiplexing.

32. The transmitting station of claim 24, wherein the transmitting processing module comprises:

a spectrum shifting unit configured to modulate data on the M basic sub-bands to a designated radio frequency band by spectrum shifting.

The transmitting station according to claim 32, wherein the sending processing module further comprises:

An IFFT processing unit of length M*K points is used to perform IFFT processing on the data and output to the spectrum! & shift unit; Where K represents the number of subcarriers included in one basic subband.

The transmitting station according to claim 33, wherein: the input sample sampling rate of the IFFT processing unit is M*fs; and fs represents an input sample sampling rate of an IFFT/FFT corresponding to a basic sub-band.

The transmitting station according to claim 33, wherein the sending processing module further comprises:

And a filtering processing unit, configured to perform shaping filtering processing on the IFFT processed data, and output the data to the spectrum shifting unit.

36. The transmitting station of claim 28, wherein the transmitting processing module comprises:

The subcarrier generating unit sets a guard band at the edge of each of the subbands by providing virtual subcarriers at both ends of each subband.

37. The transmitting station of claim 29, wherein the transmitting processing module comprises:

The subcarrier generating unit sets a virtual subcarrier at both ends of the combined frequency band by setting a virtual subcarrier at both ends of the frequency band combined by the M basic subbands.

The transmitting station according to claim 24, wherein the basic sub-band has a bandwidth of 20 MHz.

39. The transmitting station of claim 33, wherein K = 256.

40. The transmitting station of claim 34, wherein fs = 20 MHz.

41. The transmitting station of claim 24, wherein M = ²ⁿ and n is a natural number.

42. The transmitting station of claim 41, wherein n = 0, 1 or 2.

43. A method for transmitting a resource indication, comprising: scheduling one or more subchannels;

Generating a control signaling, including a bitmap for indicating one or more subchannels to be scheduled; transmitting the control signaling.

44. A device for transmitting a resource indication, comprising: a scheduling module, configured to schedule one or more subchannels;

An encapsulating module, configured to generate a control signaling, including a bitmap for indicating one or more subchannels to be scheduled;

And a sending module, configured to send the control signaling.

45. A method for receiving a resource indication, comprising: receiving a control signaling, parsing a bitmap for indicating a scheduled subchannel, and learning one or more subchannels that are scheduled;

Information is passed on the scheduled one or more subchannels.

46. A receiving device for resource indication, comprising:

a receiving module, configured to receive a control signaling,

a parsing module, configured to parse a bitmap in the control signaling for indicating a scheduled subchannel, and learn one or more subchannels that are scheduled;

And a sending module, transmitting information on the scheduled one or more subchannels.

47. A method for transmitting a resource indication, comprising:

Setting a bit group for indicating subchannel scheduling, where each bit corresponds to one subchannel; and setting one or more bits corresponding to one or more subchannels scheduled to the first according to the result of subchannel scheduling Value

The bit group is transmitted through a control signaling.

48. A device for transmitting a resource indication, comprising:

a scheduling module, configured to set a bit group for indicating subchannel scheduling, where each bit corresponds to one subchannel;

An encapsulating module, configured to set one or more bits corresponding to one or more subchannels to be a first value according to a result of subchannel scheduling; and a sending module, configured to send the bit by using one control signaling group.

49. A method for receiving a resource indication, comprising:

Receiving a control signaling;

Obtaining a bit group for indicating subchannel scheduling, wherein each bit corresponds to one subchannel; and determining one or more corresponding one or more bits according to the first value in the bit group Subchannels are scheduled;

Information is passed on the scheduled one or more subchannels.

50. A receiving device for resource indication, comprising:

a receiving module, configured to receive a control signaling;

a parsing module, configured to obtain a bit group for indicating subchannel scheduling, where each bit corresponds to one subchannel;

a sending module, configured to learn, according to one or more bits set to the first value in the bit group, that the corresponding one or more subchannels are scheduled, and in the scheduled one or more subchannels Pass the information on.