WO2008019600A1 - Procédé pour effectuer une planification de domaine fréquentiel dans un système duplex à répartition dans le temps, et système correspondant - Google Patents
Procédé pour effectuer une planification de domaine fréquentiel dans un système duplex à répartition dans le temps, et système correspondant Download PDFInfo
- Publication number
- WO2008019600A1 WO2008019600A1 PCT/CN2007/002452 CN2007002452W WO2008019600A1 WO 2008019600 A1 WO2008019600 A1 WO 2008019600A1 CN 2007002452 W CN2007002452 W CN 2007002452W WO 2008019600 A1 WO2008019600 A1 WO 2008019600A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- physical resource
- resource block
- matrix
- channel
- impulse response
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
- H04L5/14—Two-way operation using the same type of signal, i.e. duplex
- H04L5/1469—Two-way operation using the same type of signal, i.e. duplex using time-sharing
- H04L5/1484—Two-way operation using the same type of signal, i.e. duplex using time-sharing operating bytewise
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J1/00—Frequency-division multiplex systems
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L25/03343—Arrangements at the transmitter end
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
- H04L5/003—Arrangements for allocating sub-channels of the transmission path
- H04L5/0058—Allocation criteria
- H04L5/006—Quality of the received signal, e.g. BER, SNR, water filling
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L2025/0335—Arrangements for removing intersymbol interference characterised by the type of transmission
- H04L2025/03375—Passband transmission
- H04L2025/03414—Multicarrier
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L25/00—Baseband systems
- H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
- H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03006—Arrangements for removing intersymbol interference
- H04L2025/0335—Arrangements for removing intersymbol interference characterised by the type of transmission
- H04L2025/03426—Arrangements for removing intersymbol interference characterised by the type of transmission transmission using multiple-input and multiple-output channels
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2602—Signal structure
- H04L27/261—Details of reference signals
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
- H04L5/0001—Arrangements for dividing the transmission path
- H04L5/0014—Three-dimensional division
- H04L5/0023—Time-frequency-space
Definitions
- the present invention relates to an Orthogonal Frequency Division Multiplexing (OFDM) technology in the field of communications, and in particular, to a method and system for implementing frequency domain scheduling in a time division duplex multiplexing system.
- OFDM Orthogonal Frequency Division Multiplexing
- Frequency domain scheduling In an OFDM-based time division duplex (TDD) communication system, frequency domain scheduling can be used to improve the communication performance of the system.
- Frequency domain scheduling refers to a method of selecting the appropriate sub-band of transmission data for the user terminal, thereby fully utilizing the frequency selectivity in the broadband communication system.
- the relative power of subcarriers received by different user terminals is shown.
- the relative power of each subcarrier received by different user terminals is compared with the same reference value.
- User 1 is in the 30th to 120th subcarriers.
- the relative power is higher, and the relative power of user 2 on the 120-160 and 240-280 subcarriers is higher.
- resource allocation is performed, subcarriers 30 - 120 are allocated to user 1 for use, and 4 subcarriers 120-160 and 240-280 are allocated to user 2, so that each user always selects the subband to which it is most suitable for transmission.
- the transmission of data thereby obtaining multiuser diversity gain.
- a user terminal can always be found, and the sub-band is allocated to the user terminal to maximize the efficiency of the sub-band, thereby maximally developing the communication capability of the wireless channel.
- linear airspace precoding/beamforming techniques can be used to improve system performance.
- the linear spatial precoding technique refers to a technique of mapping a data stream to a plurality of antennas for transmission by a linear precoding operation when there are multiple transmitting antennas at the transmitting end.
- L data streams X form a corresponding transmitted signal Y on M antennas through a precoder.
- the linear spatial precoding operation is equivalent to a precoding matrix V, that is, ⁇ , where the dimension of X is Lxl, the dimension of Y is Mxl, the dimension of V The number is MxL.
- the linear spatial precoding operation is now beamforming.
- the precoding matrix V is calculated using a channel impulse response matrix.
- the base station When the base station obtains the precoding matrix by means of channel sounding, the base station calculates a channel impulse response matrix according to the uplink unprecoded reference symbols sent by the user equipment, and then calculates a linear precoding matrix according to the channel impulse response matrix.
- the downlink reference symbols and data symbols transmitted by the base station to the user terminal simultaneously perform linear spatial precoding processing, and the user terminal does not need to know the precoding matrix, nor does it need to estimate the channel response between each transmitting and receiving antenna. It is necessary to estimate the equivalent channel response matrix of the precoding matrix and the channel matrix synthesis, so that the data can be demodulated, thereby effectively reducing the reference symbol overhead of the transmitting end, and supporting any type of precoding operation (including beamforming). .
- this implementation method can track the channel response characteristics in real time and does not approximate the calculated precoding matrix, and there is no approximation loss caused by the approximation.
- the user terminal cannot calculate the channel quality indication based on the reference symbols after precoding, resulting in loss of system frequency domain scheduling performance.
- the base station may also obtain a precoding matrix by using a feedback-based manner, and feedback channel state information and a precoding matrix through the user terminal.
- the user terminal needs to feed back a large amount of information, and the feedback information is Loss, and sometimes even mis-transmission, results in reduced system precoding/beamforming performance.
- An embodiment of the present invention provides a method and system for implementing frequency domain scheduling in a time division duplex multiplexing system, which is used to solve the problem that frequency domain scheduling cannot be performed when a precoding matrix is obtained by using a channel sounding method in the prior art.
- a method for implementing frequency domain scheduling in a time division duplex multiplexing system includes the steps of:
- the first device sends the unprecoded reference symbol to the second device
- Frequency domain scheduling is performed according to the channel quality indicator.
- a communication system comprising:
- a first device configured to send a non-precoded reference symbol
- a second device configured to obtain, according to the reference symbol, an impulse response matrix of a channel used by the first device to send the reference symbol, and obtain a linear airspace pre-selection of the candidate physical resource block used to send data to the first device according to the impulse response matrix.
- a communication system comprising:
- a first device configured to send a non-precoded reference symbol and perform frequency domain scheduling according to a channel quality indication fed back by the second device;
- a second device configured to obtain, according to the reference symbol, an impulse response matrix of a channel used by the first device to send the reference symbol, and obtain a linear airspace of a candidate physical resource block used to send data to the first device according to the impulse response matrix.
- a precoding matrix and obtaining a channel quality indicator of the corresponding physical resource block according to the impulse response matrix and the linear spatial precoding matrix, and transmitting the channel quality indication to the first device.
- the first device sends a non-precoded reference symbol to the second device, and the second device obtains an impulse response matrix of the channel used by the first device to send the reference symbol according to the reference symbol, and obtains according to the impulse response matrix. And transmitting, to the first device, a linear spatial precoding matrix of the physical resource block occupied by the data, and then obtaining a channel quality indication of the corresponding physical resource block according to the impulse response matrix and the linear spatial precoding matrix.
- 1 is a schematic diagram of relative power of subcarriers received by a receiving end user in the prior art
- FIG. 2 is a schematic diagram of a prior art hollow domain linear precoding operation
- FIG. 3 is a schematic diagram of a time slot structure of OFDMA in an embodiment of the present invention.
- FIG. 4 is a schematic diagram of a slot structure of SC-FDMA according to an embodiment of the present invention.
- FIG. 5 is a schematic diagram of a range of available frequency bands of a user terminal according to an embodiment of the present invention.
- FIG. 6 is a schematic diagram of subband division in an embodiment of the present invention.
- FIG. 7 is a schematic structural diagram of a system in an embodiment of the present invention.
- FIG. 8 is a schematic structural diagram of a base station side processing apparatus according to an embodiment of the present invention.
- FIG. 9 is a flowchart of processing for performing linear spatial precoding and frequency domain scheduling in an embodiment of the present invention. detailed description
- the user terminal is used to send the unprecoded uplink reference symbol to the base station, and the base station obtains the channel impact according to the reference symbol base station. And responding to the matrix and calculating a linear spatial precoding matrix corresponding to each downlink physical resource block, and then obtaining a channel quality indicator of the downlink physical resource block according to the channel impulse response matrix and the linear spatial precoding matrix for frequency domain scheduling.
- the downlink transmission based on the OFDM modulation technology adopts the OFDMA multiple access method
- the uplink transmission adopts the SC-FDMA multiple access method.
- An OFDMA system refers to an OFDM system that can distinguish users in both the time domain and the frequency domain, that is, data of multiple users can be transmitted in different time slots or in one time slot.
- Each user's signal is generated in the frequency domain, corresponding to data on several subcarriers, and then fast inverse Fourier transform (IFFT transform) to the time The transmission system in which the domain processes and transmits.
- IFFT transform fast inverse Fourier transform
- the SC-FDMA system refers to a single-carrier transmission system that can distinguish users in the time domain and the frequency domain, that is, data of multiple users can be transmitted in different time slots, or can be transmitted in one time slot.
- Each user's signal is first generated in the time domain, and then subjected to operations such as discrete Fourier transform (DFT, Discrete Fourier Transform) operation to perform frequency domain subcarrier mapping operations, and then IFFT transform time domain processing and transmission.
- DFT discrete Fourier transform
- SC-FDMA For 3GPP EUTRA systems, OFDMA and SC-FDMA have different slot structures.
- FIG. 3 a schematic structural diagram of a downlink transmission OFDMA slot is shown.
- One slot consists of 9 OFDM symbols and a time interval TI.
- TI can be 0 in length.
- a time slot is composed of 8 long blocks LB1 ⁇ LB8, 2 short blocks SB1 and SB2, a slot interval TI and a cyclic prefix CP before each long block or short block, wherein the long blocks LB1 ⁇ LB8 are used for bearer services.
- Data, short blocks SB1 and SB2 are used to carry the uplink reference symbols, and the length of time ⁇ can be zero.
- the uplink reference symbols in the available frequency bands are discretely distributed in the frequency domain.
- the available frequency band range refers to the frequency band range that can be used for scheduling, and refers to the overlapping portion of the working bandwidth of the terminal and the working bandwidth of the base station.
- FIG. 5 a schematic diagram of the available frequency band range of the user terminal is shown.
- the working bandwidth of the terminal is 10 MHz
- the working bandwidth of the base station is 5 MHz
- the center carrier of the system is located at the center of 5 MHz, located at 1/4 of 10 MHz
- the overlapping 5 MHz band is The range of bands available to the system.
- the system may also allocate an available frequency band range to each user terminal, and each user terminal can only transmit the uplink reference symbols within the available frequency band. For example: When the working bandwidth of the user terminal and the base station is 10 MHz, the entire working bandwidth is divided into two equal parts, each part having a size of 5 MHz, and the user terminal can only select one of the available frequency bands of 5 MHz to transmit. Upstream reference symbol.
- the size of the available frequency band of the user terminal may be dynamically or semi-statically adjusted according to the uplink resource allocation situation, for example, when a large number of uplink resources are not used for uplink transmission, and when idle, the user may be allowed.
- the terminal transmits an uplink reference symbol on the idle subcarriers, thereby expanding the available frequency band range.
- the entire working bandwidth is divided into several sub-bands from the frequency domain, and the sub-band is composed of a plurality of consecutive sub-carriers, and the division of the time domain can further divide the physical resources of the system.
- each transmission slot in one sub-band is divided into multiple physical resource blocks, and each physical resource block (PRB) is composed of M consecutive subcarriers on all OFDM symbols in one transmission slot.
- M is generally 25;
- one transmission time slot is divided into multiple resource units (RU, Resource Unit), and each resource unit is N of all the long blocks in one transmission time slot. Consecutive or discontinuous subcarriers are formed, and the value of N is also generally 25.
- FIG. 6 is a schematic diagram of the sub-band allocation in the embodiment, showing the correspondence between the unprecoded uplink reference symbols and the downlink physical resource blocks on the sub-band, and 610 in the figure indicates the unpre-coded uplink reference symbols, 620.
- the unprecoded uplink reference symbols 610 are discretely distributed (discrete in frequency domain) on two short blocks (SB1 and SB2) in one slot, or one short block (SB1 or SB2) in one slot or one Discrete distribution over the available frequency bands on long blocks.
- Each subband may correspond to a plurality of physical resource blocks in a plurality of downlink transmission slots.
- the base station can obtain the uplink channel state information on each subband in the available frequency band by using the uplink channel sounding. Due to the channel symmetry of the TDD system, that is, when the channel state changes slowly with time (such as low-speed movement), the uplink channel state information is the same as the downlink channel state information in the same sub-band, in this embodiment. Calculating a precoding matrix used on the downlink physical resource block according to the uplink channel state information.
- the uplink reference symbols sent in one uplink time slot may correspond to physical resource blocks in multiple downlink time slots.
- FIG. 7 is a schematic structural diagram of a system according to the embodiment, including a user terminal 710 and a base station 720.
- the user terminal 710 includes a sending unit 7101 for transmitting the unprecoded uplink reference symbol to the base station 720, and a receiving unit 7102 for receiving the precoding matrix transmitted by the base station 720 for linear precoding. Data symbols and downstream reference symbols.
- Base station The 720 is configured to perform channel sounding according to the uncoded uplink reference symbols sent by the user terminal 710, obtain uplink channel state information, and perform spatial domain linear precoding and frequency domain scheduling in the downlink direction.
- FIG. 8 is a schematic structural diagram of a base station side processing apparatus according to the embodiment, including an uplink channel detector 801, a precoding matrix calculator 802, a channel quality indicator calculator 803, a physical resource allocator 804, and a data modulation and encoder 805. And a linear precoder 806.
- the number obtains an uplink channel impulse response matrix on each subcarrier of the user terminal 710 in the available frequency band, and transmits the matrix to the precoding matrix calculator 802 and the channel quality indicator calculator 803.
- the precoding matrix calculator 802 is configured to obtain a precoding matrix on each downlink physical resource block according to the obtained uplink channel state information on each subcarrier, and transmit the precoding matrix to the channel quality indicator calculator 803, physical Resource allocator 804 and linear precoder 806.
- the channel quality indicator calculator 803 is configured to obtain, according to the obtained precoding matrix on each downlink physical resource block, an uplink channel impulse response matrix on each subcarrier, a channel quality indicator on each downlink physical resource block, and The channel quality indication is communicated to physical resource allocator 804.
- the physical resource allocator 804 is configured to allocate a downlink physical resource block to the user terminal 710 according to the data block size that the user terminal 710 desires to transmit in the downlink direction, and the obtained channel quality indication on each physical resource block, and allocate the physical resource to the physical resource.
- the block information and corresponding channel quality indication are communicated to data modulation and encoder 805.
- the data modulation and encoder 805 is configured to modulate and encode the data bits according to the channel quality indication on each downlink physical resource block allocated for the user terminal 710, form a data symbol, and transmit the data symbol to the linear precoder. 806.
- the linear precoder 806 is used to map the data symbols on each downlink physical resource block and the corresponding processing flow for linear spatial precoding and frequency domain scheduling according to the embodiment shown in FIG. 9.
- the processing procedure is as follows:
- Step 901 The user terminal sends an uplink reference symbol covering the entire available frequency band range.
- Step 902 The base station calculates, by using an uplink channel sounding method, an uplink channel impulse response matrix on each subcarrier of the user terminal in the available frequency band.
- Step 903 The base station calculates a precoding matrix on each downlink physical resource block according to the obtained uplink channel impulse response matrix on each subcarrier.
- Step 904 The base station calculates a channel quality indicator on each downlink physical resource block according to the calculated precoding matrix on each downlink physical resource block and the uplink channel impulse response matrix on each subcarrier.
- Step 905 The base station allocates a downlink physical resource block to the user terminal according to the data block size that the user terminal desires to transmit in the downlink direction, and the calculated channel quality indicator on each downlink physical resource block.
- Step 906 The base station modulates and codes the data bits sent in the downlink according to the channel quality indication on each downlink physical resource block allocated for the user terminal, to form a data symbol.
- the base station When modulating and encoding the downlink data bits, when the number of physical resource blocks allocated to the user terminal is multiple, the base station first divides the data bits according to the channel quality indication corresponding to the physical resource block allocated to the user terminal, After the data bits are divided, the modulation mode and the coding rate corresponding to the corresponding channel quality indicator on the physical resource block are independently modulated and coded; if only one physical resource block is allocated to the user terminal, the data bits are not required to be performed. Division.
- the data bits can be uniformly modulated and encoded, and then uniformly distributed to the respective physical resource blocks.
- a moderate channel quality indicator may be selected in multiple channel quality indicators corresponding to each physical resource block, and used to determine a modulation and coding mode used in unified modulation and coding; Linear spatial precoding matrix corresponding to resource blocks and individual physical resources A channel quality response matrix is calculated from the channel impulse response matrix on each subcarrier in the block, and the channel quality indicator is used to determine the modulation and coding mode.
- Step 907 The base station performs linear spatial precoding on the data symbols and the corresponding reference symbols on each downlink physical resource block according to the linear spatial precoding matrix corresponding to each downlink physical resource block.
- the data symbols on each physical resource block are serially and transformed to form a plurality of data streams, and then each of the data streams is inserted into a corresponding reference symbol and then passed through a corresponding linear spatial precoding matrix.
- Transform generates signals transmitted on multiple antennas. If multiple physical resource blocks allocated to the same user terminal are consecutive in the frequency domain and/or the time domain, for each of the parallel transmitted data symbols and corresponding reference symbols within each physical resource block, each of the data symbols and corresponding reference symbols may be used.
- the linear spatial precoding matrix corresponding to the physical resource block is precoded separately; or the average value of the linear spatial precoding matrix corresponding to each physical resource block may be precoded; or the channel impulse response matrix on the physical resource blocks , Recalculate a linear spatial precoding matrix.
- step 901 when the user terminal sends an uplink reference symbol covering the entire available frequency band range, it may be sent together with the data symbol, for example, using the short block in the uplink SC-FDMA slot to send the uplink reference symbol, where a part of the uplink reference symbol is used.
- the uplink data symbol is demodulated; or, the uplink reference symbol is not used to demodulate the uplink data symbol.
- the uplink reference symbols carried by the different short blocks may also cover different frequency bands, for example, the available frequency band range is divided into two parts, where SB1 carries The uplink reference symbol covers the first portion of the available frequency band range; the uplink reference symbol carried by SB2 covers the second portion of the available frequency band range.
- step 902 when the uplink user terminal uses a short block (SB1 or SB2) or uses a long block to transmit discrete uplink reference symbols in the frequency domain within the available frequency band, the base station first obtains the subcarriers on which the discrete points are located. The channel impulse response is then obtained by frequency domain interpolation to obtain an uplink channel impulse response on each subcarrier in the available frequency band, thereby completing the uplink channel sounding.
- SB1 or SB2 short block
- SB2 short block
- a long block to transmit discrete uplink reference symbols in the frequency domain within the available frequency band
- the base station may select an uplink reference symbol carried on one of the short blocks. Perform uplink channel sounding; or use the uplink reference symbols carried on the two short blocks for uplink channel sounding, and then average the uplink channel impulse responses corresponding to the two short blocks. If the uplink reference symbols carried by the two short blocks cover different frequency bands (ie, respectively cover a part of the available frequency band range), the uplink reference symbols carried on one of the short blocks are respectively used to perform uplink in the corresponding frequency range. Channel detection.
- step 903 when calculating the linear precoding matrix, there are two cases of the uplink channel state information obtained by the channel impulse response matrix: A. The obtained uplink channel state information is sufficient; B. The obtained uplink channel state information is insufficient. The following two cases are described separately.
- the channel state information is obtained by mutually orthogonal unprecoded reference symbols transmitted on a plurality of antennas in the uplink direction of the user terminal, the channel state information is sufficient.
- the number of transmitting antennas of the base station is M
- the number of receiving antennas of the terminal is K.
- the reference symbols are transmitted on the K antennas in the uplink direction, and are orthogonal to each other, and are received using M receiving antennas, then according to each
- the dimension of the uplink channel impulse response matrix Gj obtained by the uplink reference symbols on the subcarriers is MxK, where j represents the subcarrier sequence number, that is, sufficient channel state information. Transmitting the orthogonal reference symbols on different antennas can be achieved by transmitting on different subcarriers.
- the uplink reference symbols on antenna 1 are transmitted on the 1st, 6th, 11th...subcarriers
- the uplink reference symbols on antenna 2 are transmitted on the 2nd, 8th, 12th... subcarriers.
- the uplink channel impulse response matrix Gj of different subcarriers in one physical resource block needs to be averaged to obtain a channel impulse response matrix H DL corresponding to the physical resource block, and then according to the The channel impulse response matrix H DIj performs the calculation of the precoding matrix.
- the channel channel impulse response Hu has a dimension of MXK, which corresponds to the downlink channel impact. , its dimension is KxM, and H DL is singular value decomposition (SVD, singular value decomposition),
- U is the unitary matrix with dimension KxK
- ie U H U I
- ⁇ is the unitary matrix with dimension ⁇
- ⁇ V n V l
- I represents the unit matrix
- the superscript H represents the conjugate rotation of the matrix
- the operation is performed by singular values of the channel matrix H D1 , and the dimension is KxM.
- the channel state information is obtained by a reference symbol transmitted by the user terminal on one antenna in the uplink direction or the same reference symbol transmitted from the plurality of antennas, the channel state information is insufficient.
- the number of transmitting antennas of the base station is M
- the number of receiving antennas of the user terminal is K
- the dimension of the uplink channel impulse response matrix Gj obtained according to the uplink reference symbols on each subcarrier is Mxl, where j represents the subcarrier number
- the base station obtains The channel status information is insufficient.
- the uplink channel impulse response matrix Gj of different subcarriers in one physical resource block is first averaged to obtain an uplink channel impulse response HUL , and then the downlink corresponding to the physical resource block is obtained.
- the channel impulse response matrix H D H ⁇
- the precoding matrix is obtained by the method of transmit beamforming. For example, when the number of data streams sent downstream is L, the precoding matrix is expressed as:
- V' [ , v 2 ⁇ ⁇ ⁇ v L ]
- v ' represents the precoding column vector corresponding to the i th data stream, and the precoding column vector corresponding to each data stream is the same, ie
- V [v V ⁇ v]
- the uplink transmission mode of the user terminal is specified by the base station. After receiving the uplink reference symbol sent by the user equipment, the base station determines the transmission mode of the received uplink reference symbol, and determines whether the uplink channel state information is sufficient or insufficient. Therefore, the calculation method of the precoding matrix is determined.
- the base station obtains the channel quality indication CQI method on each downlink physical resource block according to the precoding matrix V on each downlink physical resource block and the uplink channel impulse response matrix Gj on each subcarrier as follows:
- an equivalent channel matrix ( GE )j on each subcarrier is calculated according to its precoding matrix V and the uplink channel impulse response matrix Gj on each subcarrier, ( GE )j is a Kx
- L is the number of data streams before linear spatial precoding
- K is the number of antennas at the receiving end
- j is the number of subcarriers in a physical resource block
- j l ... J, where J represents a Physical resource block neutron Total number of carriers:
- an equivalent channel matrix is used to predict the received signal-to-noise ratio on each subcarrier in the downlink direction.
- the received signal-to-noise ratio ⁇ is expressed as a function of the equivalent channel matrix ( GE )j and the signal-to-noise ratio (SNR), ie
- the downlink transmit power is the known base station transmit power, and the noise power is obtained by the base station; the interference power is measured by the user terminal and then fed back to the base station, or the downlink interference power is approximated to the uplink interference power.
- the uplink interference power is obtained by the base station side measurement, and the uplink interference power is used as the interference power used in the calculation, or the inter-cell interference is approximated as no interference, that is, the interference power is zero.
- the SNR can also be predicted by the downlink transmission signal-to-noise ratio SNR' of the uplink feedback of the user terminal.
- the base station predicts the SNR according to the ratio between the transmission power when transmitting the SNR' measurement to the user terminal and the transmission power used by the base station to transmit, that is,
- a set representing a signal to noise ratio ⁇ on all subcarriers within the physical resource block.
- One way to calculate the equivalent signal-to-noise ratio 1 is to use the EESM (OFDM Exponential Effective SIR Mapping) method. The functional relationship is as follows:
- J is the number of subcarriers in the physical resource block
- ⁇ is a parameter related to the modulation and coding mode, and the parameter is determined by simulation.
- the slot length is 0.675 ms
- the beta parameters of the OFDMA system with subcarrier spacing of 15 kHz are shown in Table 1:
- the CQI value corresponding to the physical resource block is obtained from the calculated equivalent signal to noise ratio and a predetermined threshold.
- the frequency domain scheduling process for the user terminal according to the CQI value is as follows: For example, a service time slot is divided into five physical resource blocks, and each physical resource block can be Supports 16 kinds of modulation and coding levels, corresponding to 16 CQI values respectively.
- the number of Quadrature Amplitude Modulation (QAM) symbols that can be transmitted by one physical resource block is the coding rate and the transmission block size (TBS, Transmit Block). Size ) as shown in Table 2:
- Table 3 When the amount of data that the user terminal is expected to transmit in the downlink direction is llOObits, the physics of the user is allocated according to the data block size that the user terminal desires to transmit in the downlink direction, and the calculated channel quality indicator on each physical resource block.
- the resource blocks 1 and 2 select the linear spatial precoding matrix corresponding to the downlink physical resource blocks 1 and 2 to perform linear spatial precoding on the data symbols and reference symbols transmitted by the user terminal in the downlink.
- the user terminal sends the unprecoded uplink reference symbol to the base station, obtains the impulse response matrix of the channel according to the reference symbol base station, and calculates a precoding matrix corresponding to each downlink physical resource block, and then according to the impulse response matrix and
- the precoding matrix obtains the channel quality indication of the downlink physical resource block for frequency domain scheduling, and performs linear airspace precoding according to the calculated precoding matrix, thereby solving the problem that the frequency domain scheduling technology cannot be used when using the channel detection technology, and avoiding the simultaneous Use frequency domain scheduling and linear null: I or the contradiction generated when precoding.
- the embodiment of the present invention is not limited to this.
- Another implementation manner of the present invention is that the base station sends the unprecoded downlink reference symbol to the user terminal, and the user terminal obtains the impulse response matrix of the channel according to the reference symbol and calculates corresponding to each uplink physical. a precoding matrix of the resource block, and then obtaining a channel quality indicator on the uplink physical resource block according to the precoding matrix, and feeding back the channel quality indicator to the base station, where the base station performs frequency domain scheduling according to the channel quality indicator.
- the base station performs frequency domain scheduling according to the channel quality indicator.
- the matrix obtains an equivalent channel matrix corresponding to each subcarrier, predicts the received signal to noise ratio on each subcarrier in the uplink direction according to the equivalent channel matrix and the transmission signal to noise ratio of the user terminal side, and then determines The equivalent signal to noise ratio, and the corresponding channel quality indicator is determined according to the equivalent signal to noise ratio.
- the method for calculating the channel quality indicator on the user terminal side is similar to the embodiment, and will not be described again.
- the linear spatial precoding operation is degraded into a transmit beamforming operation, and the operation can only be performed in the downlink direction.
- the linear precoding operation degenerates into a transmit beamforming operation, and the operation can only be performed in the uplink direction.
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Computer Networks & Wireless Communication (AREA)
- Power Engineering (AREA)
- Quality & Reliability (AREA)
- Mobile Radio Communication Systems (AREA)
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP07785348.9A EP2053770B1 (en) | 2006-08-14 | 2007-08-14 | A method for realizing frequency domain scheduling in the time division duplex system and the system thereof |
JP2008540440A JP4809899B2 (ja) | 2006-08-14 | 2007-08-14 | 時分割複信システムにおける周波数領域のスケジューリングを行う方法および関連システム |
US12/281,574 US7733765B2 (en) | 2006-08-14 | 2007-08-14 | Method for realizing frequency domain scheduling in the time division duplex system and the system thereof |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN200610089269.7 | 2006-08-14 | ||
CN2006100892697A CN101127747B (zh) | 2006-08-14 | 2006-08-14 | 一种时分双工复用系统中实现频域调度的方法及系统 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2008019600A1 true WO2008019600A1 (fr) | 2008-02-21 |
Family
ID=39081943
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/CN2007/002452 WO2008019600A1 (fr) | 2006-08-14 | 2007-08-14 | Procédé pour effectuer une planification de domaine fréquentiel dans un système duplex à répartition dans le temps, et système correspondant |
Country Status (6)
Country | Link |
---|---|
US (1) | US7733765B2 (zh) |
EP (1) | EP2053770B1 (zh) |
JP (1) | JP4809899B2 (zh) |
KR (1) | KR100945341B1 (zh) |
CN (1) | CN101127747B (zh) |
WO (1) | WO2008019600A1 (zh) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010013451A1 (ja) * | 2008-07-29 | 2010-02-04 | パナソニック株式会社 | Mimo送信装置及びmimo送信方法 |
JP2013513977A (ja) * | 2009-12-10 | 2013-04-22 | ゼットティーイー コーポレーション | 周波数選択スケジューリング方法及び装置 |
Families Citing this family (39)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8594704B2 (en) * | 2004-12-16 | 2013-11-26 | Atc Technologies, Llc | Location-based broadcast messaging for radioterminal users |
KR100853699B1 (ko) * | 2006-12-01 | 2008-08-25 | 한국전자통신연구원 | 이동통신 시스템의 호 설정 제어 방법 |
US8503375B2 (en) | 2007-08-13 | 2013-08-06 | Qualcomm Incorporated | Coding and multiplexing of control information in a wireless communication system |
WO2009082668A1 (en) * | 2007-12-20 | 2009-07-02 | Research In Motion Limited | Equipments and methods for uplink timing synchronization |
CN101515906B (zh) * | 2008-02-22 | 2011-10-26 | 中兴通讯股份有限公司 | 一种用于数据流与波束之间映射的预编码方法 |
JP5233331B2 (ja) * | 2008-03-12 | 2013-07-10 | 富士通株式会社 | 無線基地局、無線端末及び無線通信方法 |
CN101534265B (zh) * | 2008-03-15 | 2013-05-01 | 中兴通讯股份有限公司 | 下行专用导频和物理资源块的映射方法 |
CN101621320A (zh) * | 2008-06-30 | 2010-01-06 | 上海华为技术有限公司 | 数据传输方法以及系统和终端 |
ATE548811T1 (de) | 2008-06-30 | 2012-03-15 | Alcatel Lucent | Verfahren zur zuweisung von vorkodierungsvektoren in einem mobilen zellularen netzwerk |
CN101626264B (zh) * | 2008-07-09 | 2013-03-20 | 中兴通讯股份有限公司 | 一种无线通信系统中实现开环预编码的方法 |
CN101635595B (zh) * | 2008-07-24 | 2013-12-04 | 中兴通讯股份有限公司 | 无线资源的子信道化和资源映射方法 |
EA022237B1 (ru) | 2008-08-06 | 2015-11-30 | Шарп Кабусики Кайся | Система связи, устройство мобильной станции и способ связи |
CN101854186B (zh) * | 2009-03-30 | 2015-04-01 | 三星电子株式会社 | 用于数据传输的预编/解码方法和系统 |
CN101877684B (zh) * | 2009-04-28 | 2012-11-14 | 电信科学技术研究院 | 一种预编码矩阵的确定方法及装置 |
JP5278178B2 (ja) * | 2009-06-08 | 2013-09-04 | 富士通モバイルコミュニケーションズ株式会社 | 無線通信装置および無線通信方法 |
KR20110019284A (ko) * | 2009-08-19 | 2011-02-25 | 주식회사 팬택 | 무선통신시스템에서 상향링크 광대역 측정 신호 전송방법 및 장치, 그를 이용한 하향링크 채널 추정방법 |
KR101704812B1 (ko) * | 2010-01-26 | 2017-02-10 | 삼성전자주식회사 | 통신 시스템에서 잡음 및 간섭 전력 추정 장치 및 방법 |
CN102263600B (zh) * | 2010-05-28 | 2013-08-14 | 电信科学技术研究院 | 确定终端移动速度的方法和设备 |
US9172513B2 (en) | 2010-10-11 | 2015-10-27 | Qualcomm Incorporated | Resource assignments for uplink control channel |
CN102468947A (zh) * | 2010-11-05 | 2012-05-23 | 大唐移动通信设备有限公司 | 信道质量信息的反馈方法和设备 |
JP5314712B2 (ja) * | 2011-02-14 | 2013-10-16 | 株式会社エヌ・ティ・ティ・ドコモ | 基地局装置及びユーザ装置 |
WO2012116486A1 (en) * | 2011-02-28 | 2012-09-07 | Nec (China) Co., Ltd. | Method and apparatus for modifying channel quality indication |
US8837525B2 (en) * | 2011-03-21 | 2014-09-16 | Xiao-an Wang | Carrier-phase difference detection and tracking in multipoint broadcast channels |
CN102149130B (zh) * | 2011-04-22 | 2014-01-01 | 电信科学技术研究院 | 一种信道质量指示的上报方法、装置及系统 |
JP5620888B2 (ja) * | 2011-07-26 | 2014-11-05 | 京セラ株式会社 | 無線基地局及び通信制御方法 |
US9219533B2 (en) | 2011-10-25 | 2015-12-22 | Transpacific Ip Management Group Ltd. | Systems and methods for downlink scheduling in multiple input multiple output wireless communications systems |
JP5923786B2 (ja) * | 2012-03-16 | 2016-05-25 | シャープ株式会社 | 基地局装置及び通信方法 |
US9374184B2 (en) * | 2012-03-23 | 2016-06-21 | Nokia Solutions And Networks Oy | Controlling of code block to physical layer mapping |
CN103684668B (zh) * | 2012-09-19 | 2017-04-26 | 中兴通讯股份有限公司 | 确定信道质量指示值的方法、装置及lte终端 |
CN105191271B (zh) * | 2013-05-05 | 2018-01-23 | 领特德国公司 | 用于从分配点进行数据传输的低功率模式 |
JP6211177B2 (ja) * | 2013-06-04 | 2017-10-11 | 華為技術有限公司Huawei Technologies Co.,Ltd. | データ送信の方法および装置、ならびにユーザ機器 |
US9673957B2 (en) * | 2013-09-19 | 2017-06-06 | Telefonaktiebolaget Lm Ericsson (Publ) | System and method for providing interference characteristics for interference mitigation |
WO2015109526A1 (zh) * | 2014-01-24 | 2015-07-30 | 华为技术有限公司 | 导频信号的传输方法及装置 |
US10341043B2 (en) * | 2014-09-27 | 2019-07-02 | RF DSP Inc. | Methods for multi-user MIMO wireless communication using approximation of zero-forcing beamforming matrix |
EP3281302A1 (en) * | 2015-04-08 | 2018-02-14 | NTT Docomo, Inc. | Base station, user equipment, and method for determining precoding matrix |
CN106230545B (zh) * | 2015-07-31 | 2020-08-11 | 北京智谷睿拓技术服务有限公司 | 确定信道质量的方法及其装置 |
CN107078839B (zh) * | 2015-09-25 | 2019-12-17 | 华为技术有限公司 | 一种数据传输的方法及装置 |
CN112165439A (zh) * | 2018-01-25 | 2021-01-01 | 华为技术有限公司 | 一种信道估计方法和装置 |
CN113271130B (zh) * | 2018-05-11 | 2024-04-09 | 华为技术有限公司 | 信道估计方法和装置 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1703863A (zh) * | 2001-05-25 | 2005-11-30 | 明尼苏达大学董事会 | 无线通信网中的空时编码传输 |
WO2006019260A2 (en) * | 2004-08-17 | 2006-02-23 | Lg Electronics Inc. | Data communication in a wireless communication system using space-time coding |
Family Cites Families (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AU4238697A (en) * | 1996-08-29 | 1998-03-19 | Cisco Technology, Inc. | Spatio-temporal processing for communication |
US7099413B2 (en) * | 2000-02-07 | 2006-08-29 | At&T Corp. | Method for near optimal joint channel estimation and data detection for COFDM systems |
US6940827B2 (en) * | 2001-03-09 | 2005-09-06 | Adaptix, Inc. | Communication system using OFDM for one direction and DSSS for another direction |
US7027523B2 (en) * | 2001-06-22 | 2006-04-11 | Qualcomm Incorporated | Method and apparatus for transmitting data in a time division duplexed (TDD) communication system |
US6760388B2 (en) * | 2001-12-07 | 2004-07-06 | Qualcomm Incorporated | Time-domain transmit and receive processing with channel eigen-mode decomposition for MIMO systems |
US7020110B2 (en) * | 2002-01-08 | 2006-03-28 | Qualcomm Incorporated | Resource allocation for MIMO-OFDM communication systems |
US8208364B2 (en) * | 2002-10-25 | 2012-06-26 | Qualcomm Incorporated | MIMO system with multiple spatial multiplexing modes |
US20040192218A1 (en) * | 2003-03-31 | 2004-09-30 | Oprea Alexandru M. | System and method for channel data transmission in wireless communication systems |
KR20050000709A (ko) * | 2003-06-24 | 2005-01-06 | 삼성전자주식회사 | 다중 접속 방식을 사용하는 통신 시스템의 데이터 송수신장치 및 방법 |
FI20031079A0 (fi) * | 2003-07-16 | 2003-07-16 | Nokia Corp | Menetelmä tiedonsiirtoresurssien kontrolloimiseksi, sekä kontrolleri |
RU2408986C2 (ru) * | 2003-08-20 | 2011-01-10 | Панасоник Корпорэйшн | Устройство беспроводной связи и способ выделения поднесущих |
US7298805B2 (en) * | 2003-11-21 | 2007-11-20 | Qualcomm Incorporated | Multi-antenna transmission for spatial division multiple access |
US20050249127A1 (en) * | 2004-05-10 | 2005-11-10 | Lucent Technologies, Inc. | Method for subcarrier allocation |
JP2006115386A (ja) * | 2004-10-18 | 2006-04-27 | Matsushita Electric Ind Co Ltd | マルチキャリア送信装置およびマルチキャリア送信方法 |
KR100909539B1 (ko) * | 2004-11-09 | 2009-07-27 | 삼성전자주식회사 | 다중 안테나를 사용하는 광대역 무선 접속 시스템에서 다양한 다중안테나 기술을 지원하기 위한 장치 및 방법 |
WO2007091317A1 (ja) * | 2006-02-08 | 2007-08-16 | Fujitsu Limited | マルチアンテナ送信技術を用いた無線通信システム及び,これに適用するマルチユーザスケジューラ |
JP4836186B2 (ja) * | 2006-05-31 | 2011-12-14 | 三洋電機株式会社 | 送信装置 |
FI20075083A0 (fi) * | 2007-02-06 | 2007-02-06 | Nokia Corp | Ilmaisumenetelmä ja -laite monivuo-MIMOa varten |
US20080304558A1 (en) * | 2007-06-06 | 2008-12-11 | Hong Kong University Of Science And Technology | Hybrid time-frequency domain equalization over broadband multi-input multi-output channels |
-
2006
- 2006-08-14 CN CN2006100892697A patent/CN101127747B/zh active Active
-
2007
- 2007-08-14 JP JP2008540440A patent/JP4809899B2/ja active Active
- 2007-08-14 EP EP07785348.9A patent/EP2053770B1/en active Active
- 2007-08-14 US US12/281,574 patent/US7733765B2/en active Active
- 2007-08-14 WO PCT/CN2007/002452 patent/WO2008019600A1/zh active Application Filing
- 2007-08-14 KR KR20087013818A patent/KR100945341B1/ko active IP Right Grant
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1703863A (zh) * | 2001-05-25 | 2005-11-30 | 明尼苏达大学董事会 | 无线通信网中的空时编码传输 |
WO2006019260A2 (en) * | 2004-08-17 | 2006-02-23 | Lg Electronics Inc. | Data communication in a wireless communication system using space-time coding |
Non-Patent Citations (3)
Title |
---|
"3GPP DRAFT; RI-051407, 3RD GENERATION PARTNERSHIP PROJECT (3GPP", vol. RAN WG1, 31 October 2005, MOBILE COMPETENCE CENTRE, article "Downlink MIMO for E-UTRA" |
"Channel Sounding Overhead Analysis", 3GPP DRAFT, 9 February 2006 (2006-02-09) |
See also references of EP2053770A4 * |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2010013451A1 (ja) * | 2008-07-29 | 2010-02-04 | パナソニック株式会社 | Mimo送信装置及びmimo送信方法 |
US8493916B2 (en) | 2008-07-29 | 2013-07-23 | Panasonic Corporation | MIMO transmission device and MIMO transmission method |
US8730876B2 (en) | 2008-07-29 | 2014-05-20 | Panasonic Corporation | MIMO reception device and MIMO reception method |
US8917672B2 (en) | 2008-07-29 | 2014-12-23 | Panasonic Intellectual Property Corporation Of America | MIMO reception device and MIMO reception method |
JP2013513977A (ja) * | 2009-12-10 | 2013-04-22 | ゼットティーイー コーポレーション | 周波数選択スケジューリング方法及び装置 |
Also Published As
Publication number | Publication date |
---|---|
JP2009516438A (ja) | 2009-04-16 |
CN101127747A (zh) | 2008-02-20 |
KR100945341B1 (ko) | 2010-03-08 |
US20090052357A1 (en) | 2009-02-26 |
KR20080090392A (ko) | 2008-10-08 |
EP2053770B1 (en) | 2016-09-28 |
CN101127747B (zh) | 2010-09-08 |
US7733765B2 (en) | 2010-06-08 |
JP4809899B2 (ja) | 2011-11-09 |
EP2053770A1 (en) | 2009-04-29 |
EP2053770A4 (en) | 2011-09-28 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
WO2008019600A1 (fr) | Procédé pour effectuer une planification de domaine fréquentiel dans un système duplex à répartition dans le temps, et système correspondant | |
KR101215297B1 (ko) | 멀티캐리어 무선 네트워크에서 적응적 채널 품질 정보를송수신하기 위한 장치 및 방법 | |
US7729432B2 (en) | System and method for enhancing the performance of wireless communication systems | |
KR101079102B1 (ko) | Ofdm/ofdma 무선 통신 시스템에서의 데이터 전송 및 채널정보 추정 방법 | |
US7764931B2 (en) | Method and apparatus for transmitting/receiving feedback information representing channel quality in a MIMO-OFDM system | |
US8130847B2 (en) | Closed-loop transmission feedback in wireless communication systems | |
TWI309514B (en) | Method and apparatus for subcarrier and antenna selection in mimo-ofdm system | |
US10348529B2 (en) | Method and apparatus for signal detection in a wireless communication system | |
TWI311010B (en) | Systems and methods for adaptive bit loading in a multiple antenna orthogonal frequency division multiplexed communication system | |
US8634432B2 (en) | System and method for subcarrier allocation in a multicarrier wireless network | |
US20060025079A1 (en) | Channel estimation for a wireless communication system | |
KR100922980B1 (ko) | 다중 안테나를 사용하는 직교주파수분할다중 시스템에서 채널 추정 장치 및 방법 | |
US20090252250A1 (en) | Apparatus and method for beamforming based on generalized eigen-analysis in multiple input multiple output wireless communication system | |
KR20160031443A (ko) | 무선 통신시스템의 채널 정보 피드백을 위한 장치 및 방법 | |
CN102468947A (zh) | 信道质量信息的反馈方法和设备 | |
US20120002599A1 (en) | Implicit Channel Sounding for Closed-Loop Transmission in MIMO-OFDM Wireless Networks | |
CN101754347B (zh) | 多流波束赋形传输时cqi估计方法、系统及设备 | |
CN101540746B (zh) | 时频信道量化方法和装置及对应的移动通信终端和系统 | |
US20070237069A1 (en) | Multi-Step Channel Prediction Apparatus and Method for Adaptive Transmission in OFDM/FDD System | |
JP2009147897A (ja) | チャネル情報測定装置と方法 | |
CN103138906B (zh) | 一种用于改进上行链路探询质量的方法与设备 | |
KR20090064783A (ko) | 순환 지연을 이용하여 협력 다이버시티를 수행하는 무선통신 시스템 및 방법 | |
KR102484330B1 (ko) | 무선 통신 시스템에서 서비스들 간 간섭을 제어하기 위한 장치 및 방법 | |
Du et al. | SAMU: design and implementation of frequency selectivity-aware multi-user MIMO for WLANs | |
CN112913180A (zh) | 由设备实现的发送参考信号的方法、计算机程序产品和设备 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
REEP | Request for entry into the european phase |
Ref document number: 2007785348 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2007785348 Country of ref document: EP |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 07785348 Country of ref document: EP Kind code of ref document: A1 |
|
ENP | Entry into the national phase |
Ref document number: 2008540440 Country of ref document: JP Kind code of ref document: A |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1020087013818 Country of ref document: KR |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1853/MUMNP/2008 Country of ref document: IN |
|
WWE | Wipo information: entry into national phase |
Ref document number: 12281574 Country of ref document: US |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
NENP | Non-entry into the national phase |
Ref country code: RU |