WO2012142886A1

WO2012142886A1 - Method and system for sending multi-antenna data

Info

Publication number: WO2012142886A1
Application number: PCT/CN2012/072253
Authority: WO
Inventors: 许进; 郁光辉; 梁春丽; 郝鹏; 戴博; 吴欣
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-04-22
Filing date: 2012-03-13
Publication date: 2012-10-26
Also published as: CN102752082A; CN102752082B

Abstract

A method and system for sending multi-antenna data. The method includes: encoding each transmission block to be transmitted; for each transmission block, modulate the data obtained after encoding the transmission block, then map the same onto an integral number of orthogonal frequency division multiplexing (OFDM) symbols; in the situation where a user only has time domain scheduling and each user occupies the integral number of OFDM symbols in the time domain and occupies the whole bandwidth in the frequency domain, dividing the integral number of OFDM symbols into sub-bands according to frequency selectivity difference; allocating a layer number to each sub-band of each OFDM symbol; and grouping a plurality of successive OFDM symbols into a radio frame, then sending the same to a receiving end. By using the above technical solution, when transmitting multi-antenna data, the sending end flexibly adjusts the data modulation mode on each layer, which can ensure the data transmission quality effectively and acquire the gain of adaptive modulation and coding, thereby higher throughput and peak rate can be further acquired.

Description

Method and system for transmitting multi-antenna data

Technical field

The present invention relates to a mobile communication system, and in particular, to a method and system for transmitting multi-antenna data.

Background technique

In mobile communication systems, due to the time-varying characteristics of wireless fading channels, there is a large amount of uncertainty in the communication process. In order to improve the system throughput, high-order modulation with high transmission rate and less redundant error correction code are usually used for communication, so that the system throughput is greatly improved when the signal-to-noise ratio of the wireless fading channel is ideal, but when When the channel is in deep fading, communication cannot be guaranteed to be reliable and stable. In order to ensure the reliability of communication, low-order modulation with low transmission rate and large redundant error correction code are usually used for communication, that is, the wireless channel is in deep fading. The communication is guaranteed to be reliable and stable, but when the channel signal-to-noise ratio is relatively high, the transmission rate is low, which limits the improvement of the system throughput, thereby causing waste of resources.

In the early stage of the development of mobile communication technology, in order to combat the time-varying characteristics of wireless fading channels, only the transmission power of the transmitter can be increased and the modulation coding method of low-order and large redundancy can be used to ensure the system in the deep fading of the channel. Communication quality, there is no way to consider how to improve the throughput of the system. With the continuous advancement of the technical level, there has been a technology that can adaptively adjust the transmission power of the transmitter, the modulation and coding mode, and the frame length of the data according to the channel state to overcome the time-varying characteristics of the channel, thereby obtaining an optimal communication effect. It is called adaptive technology.

Today, with the rapid development of mobile broadband, wireless hotspot transmission technology has received more and more attention. Unlike ordinary third-generation mobile communication technologies, wireless hotspot transmissions usually have larger transmission bandwidth and higher data throughput. Take the IEEE (Institute of Electrical and Electronics Engineers) 802.11ac technology as an example, the maximum transmission bandwidth can reach 160 megabytes, and the peak transmission rate can exceed 3G bps (bits per second). Wireless data communication solutions for hotspots.

Although the indoor environment is generally stable, the frequency selective effect of the channel is still unavoidable due to the large transmission bandwidth, but this is not considered in technologies such as IEEE 802.1 lac. For example, in IEEE 802.11ac, each user's data is transmitted over the full bandwidth, not according to each The data transmission method is adjusted correspondingly according to the channel conditions on the frequency band.

Summary of the invention

The technical problem to be solved by the present invention is to provide a method and system for transmitting multi-antenna data, so as to solve the defect that the existing system cannot adjust the data transmission mode according to different channel conditions in each frequency band.

In order to solve the above problems, the present invention uses the following technical solutions:

A method for transmitting multi-antenna data includes:

Encoding each transport block to be transmitted;

For each transport block, the data obtained by encoding the transport block is modulated, and then mapped to an integer number of orthogonal frequency division multiplexing (OFDM) symbols;

Wherein, when the user only has time domain scheduling, and each user occupies an integer number of OFDM symbols in the time domain and occupies the entire bandwidth in the frequency domain, the subbands are divided into integer OFDM symbols according to the frequency selectivity difference; The number of layers allocated to each sub-band of an OFDM symbol;

A plurality of consecutive OFDM symbols are combined into one radio frame and sent to the receiving end.

Wherein, in each OFDM symbol, the number of layers on each sub-band is not completely the same or completely different.

The step of modulating the data obtained by encoding the transport block comprises: selecting a modulation mode according to a link quality that is to be mapped to data on a different layer of the same sub-band on the same OFDM symbol.

The step of allocating the number of layers for each subband of each OFDM symbol includes:

The value of the spatial rank (Rank) of each sub-band in the OFDM symbol is the number of layers allocated to each sub-band of each OFDM symbol, and the maximum number of layers that can be allocated to the sub-band with a high spatial rank is greater than or equal to the low spatial rank. The maximum number of layers that the subband can allocate.

The steps of encoding each transport block to be transmitted include:

A fixed bit rate encoding is performed for each transport block to be transmitted.

The sending method further includes: Before performing modulation, if it is determined that the data to be modulated is insufficient to occupy an integer number of OFDM symbols after being modulated and mapped, then the padding bits of the corresponding number of bits are added after the data to be modulated, and then Modulation and mapping are performed such that the data to be modulated after the padding is added can be filled with an integer number of OFDM symbols after being modulated and mapped.

The sending method further includes:

After mapping to an integer number of the OFDM symbols, if it is determined that an integer number of the OFDM symbols are not full, a corresponding number of padding symbols are filled in an integer number of the OFDM symbols to occupy an integer number of OFDM symbol.

The modulation method includes: a quadrature phase shift keying modulation method, a quadrature amplitude modulation method including 16 symbols, a quadrature amplitude modulation method including 64 symbols, or a quadrature amplitude modulation method including 256 symbols.

Where: The size of the transport block to be transmitted is determined by the packet size of the medium access control layer.

A transmission system for multi-antenna data includes a first device, a second device, and a third device, wherein:

The first device is configured to: encode each transport block to be transmitted;

The second device is configured to: after each transmission block, the data obtained by encoding the transport block is modulated by a modulation method, and then mapped to an integer number of orthogonal frequency division multiplexing (OFDM) symbols; If the user only has time domain scheduling and each user occupies an integer number of OFDM symbols in the time domain and occupies the entire bandwidth in the frequency domain, the subbands are divided into integer OFDM symbols according to the frequency selectivity difference; The number of layers allocated to each subband of the OFDM symbol;

The third device is configured to: combine a plurality of consecutive OFDM symbols into one radio frame, and send the signal to the receiving end.

The second device is configured to modulate data obtained by encoding the transport block in the following manner:

According to the link quality, it is mapped to the same subband on the same OFDM symbol. The data on the same layer is selected for modulation.

Wherein the second device is arranged to allocate layers for each sub-band of each OFDM symbol in the following manner:

The first device is configured to encode each transport block to be transmitted in the following manner: Each transport block to be transmitted is coded at a fixed code rate.

Wherein: the second device is further configured to: before each modulation, if it is determined that the data to be modulated is insufficient to occupy an integer number of OFDM symbols after being modulated and mapped, then the data to be modulated is After adding the padding bits of the corresponding number of bits, the modulation and mapping are performed, so that the data to be modulated after the padding is increased can be occupied by integers after being modulated and mapped.

OFDM symbol.

The second device is further configured to: after mapping to an integer number of the OFDM symbols, if it is determined that an integer number of the OFDM symbols are not full, fill the corresponding number in the integer number of the OFDM symbols a padding symbol to occupy an integer number of the OFDM symbols.

After using the above technical solution, the transmitting end flexibly adjusts the data modulation mode on each layer when performing multi-antenna data transmission, can effectively ensure the quality of data transmission, and obtain the gain of adaptive code modulation, thereby further obtaining Higher throughput and peak speed.

BRIEF abstract

1 is a flowchart of a method for transmitting multi-antenna data in an embodiment of the present invention;

Fig. 2 is a schematic view showing an application example of the present invention.

Preferred embodiment of the invention

In order to make the objects, technical solutions and advantages of the present invention more clear, the following will be combined with the accompanying drawings. The embodiments of the present invention will be described in detail. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other. These combinations are all within the scope of the invention.

In the embodiment of the present invention, a method for transmitting multi-antenna data, as shown in FIG. 1 , includes: a, encoding, by a transmitting end, each transport block to be transmitted;

Wherein, when encoding, a fixed bit rate encoding method may be used; the encoding method may use Turbo code, Convolution code, Low Density Parity Check (LDPC, Low Density Parity Check). Code ) or other encoding method;

b. For each transport block, the transmitting end modulates the data obtained by encoding the transport block, and then maps to an integer number of orthogonal frequency division multiplexing (OFDM, Orthogonal Frequency Division).

Multiplexing)

Wherein, in each OFDM symbol, the number of layers on each sub-band is the same or not identical; in addition, preferably, in one OFDM symbol, the modulation mode used on different layers of each sub-band may be the same, It may not be exactly the same, that is, selecting a corresponding modulation mode to be mapped to the data to be modulated in the above integer OFDM symbols, and then performing modulation; wherein, is data to be mapped on different layers of the same subband in the same OFDM symbol The modulation used is the same or not the same. Here, selecting a corresponding modulation mode for the data to be modulated to be mapped into the above integer OFDM symbols means: using a high-order modulation mode on a layer with a good link quality, in a layer with poor link quality The upper layer uses low-order modulation, that is, the code modulation mode is selected according to the link quality of each layer, so that the data transmission quality can be effectively ensured and the adaptive code modulation gain can be obtained.

c. A plurality of consecutive OFDM symbols are combined into one radio frame and sent to the receiving user.

In step a, the size of the transport block to be transmitted is determined by the packet size of the Medium Access Control (MAC).

In another embodiment of the present invention, in step b, the modulation mode applicable to the data on each sub-band is specifically: Quadrature Phase Shift Keying (QPSK), which includes 16 symbols. Digital amplitude modulation (16QAM, 16 Quadrature Amplitude Modulation), quadrature amplitude modulation (64QAM) containing 64 symbols, or quadrature amplitude modulation (256QAM) including 256 symbols. In another embodiment of the present invention, in each OFDM symbol, the transmitting end may allocate a layer according to a value of a spatial rank (Rank) of each subband in the OFDM symbol, that is, may be a spatial rank. The maximum number of layers of the subband allocation with a high value is greater than or equal to the maximum number of layers that can be allocated for the subband with a low spatial rank value. But in the end, the number of layers used in each sub-band is determined by the upper-layer network element (such as the base station).

It is assumed that the spatial rank value of subband 1 is i, the spatial rank value of subband 2 is j, and "," the maximum number of layers that can be allocated for subband 1 is i, and the number of layers that can be allocated for subband 2 The maximum value is in step b. For each transport block, if the transmitting end determines that the data to be modulated is insufficient to occupy an integer number of OFDM symbols after being modulated and mapped, the corresponding digits are added after the data to be modulated. After the bits are filled, subsequent modulation and mapping processing is performed.

Or, in another embodiment of the present invention, after the data obtained by encoding the transport block is modulated and mapped onto the integer number of OFDM symbols, if it is determined that the integer OFDM symbols are not occupied, A corresponding number of padding symbols are padded in the integer number of OFDM symbols, thereby occupying the integer number of OFDM symbols.

In another embodiment of the present invention, a multi-antenna data transmission system includes a first device, a second device, and a third device, wherein:

The second device is configured to: after each of the transport blocks, the data obtained by encoding the transport block is modulated, and then mapped to an integer number of orthogonal frequency division multiplexing (OFDM) symbols; wherein, in each OFDM Within the symbol, the number of layers on each sub-band is the same or not identical;

More preferably,

The second means is arranged to modulate the data obtained by encoding the transport block in the following manner:

Modulating after selecting a corresponding modulation scheme for data to be modulated to be mapped into the integer number of OFDM symbols; wherein, is a modulation scheme for data to be mapped on different layers of the same subband in the same OFDM symbol Same or not exactly the same. More preferably,

Within each OFDM symbol, the number of layers on each sub-band is allocated according to the value of the spatial rank (Rank) of each sub-band in the OFDM symbol, and the maximum number of layers that can be allocated in the sub-band with a high spatial rank value is greater than The maximum value of the number of layers that can be allocated for a subband equal to the low spatial rank value.

More preferably,

The first means is arranged to encode each transport block to be transmitted in the following manner: Each transport block to be transmitted is coded at a fixed code rate.

More preferably,

The second device is further configured to: before each of the transport blocks, if it is determined that the data to be modulated is insufficient to occupy an integer number of OFDM symbols after being modulated and mapped, After the modulated data is added, the padding bits of the corresponding number of bits are added, and then the subsequent modulation and mapping processing is performed.

More preferably,

The second device is further configured to: after mapping to the integer number of OFDM symbols, if it is determined that the integer number of OFDM symbols are not full, filling the integer number of OFDM symbols with a corresponding number of padding A symbol that fills the integer number of OFDM symbols.

An embodiment of the present invention further provides a method for transmitting multi-antenna data, including:

Encoding each transport block to be transmitted;

The step of modulating the data obtained by encoding the transport block includes: The modulation scheme is selected based on the link quality for data to be mapped onto different layers of the same subband on the same OFDM symbol.

The steps of encoding each transport block to be transmitted include:

The sending method further includes:

Before performing modulation, if it is determined that the data to be modulated is insufficient to occupy an integer number of OFDM symbols after being modulated and mapped, then the padding bits of the corresponding number of bits are added after the data to be modulated, and then Modulation and mapping are performed such that the data to be modulated after the padding is added can be filled with an integer number of OFDM symbols after being modulated and mapped.

The sending method further includes:

An embodiment of the present invention further provides a multi-antenna data transmission system, including a first device, a second device, and a third device, where:

The second device is configured to: after each transmission block, the data obtained by encoding the transport block is modulated by a modulation method, and then mapped to an integer number of orthogonal frequency division multiplexing (OFDM) symbols In the case where the user only has time domain scheduling and each user occupies an integer number of OFDM symbols in the time domain and occupies the entire bandwidth in the frequency domain, the frequency selectivity difference is an integer number.

OFDM symbol division subband; assigns a number of layers for each subband of each OFDM symbol;

The modulation scheme is selected based on the link quality as the data on the different layers of the same sub-band to be mapped onto the same OFDM symbol.

OFDM symbol.

The invention is further illustrated by an application example below. As shown in FIG. 2, the base station sends a transport block of size Ki (i is a transport block index, i=l, 2, ...) to the user, and after encoding the LDPC code with a code rate of Ri, respectively. The encoded data of length Ni = Ki / Ri bits is generated. It should be noted that 1, 2, and 3 in each block in FIG. 2 respectively indicate the first layer, the second layer, and the third layer in the current sub-band.

The coded data is modulated and mapped onto the Si OFDM symbol, and the OFDM symbol can be divided into a plurality of sub-bands, and the number of layers on each sub-band is the same or not identical. As shown in Figure 2, for transport block 1, the encoded data fills up one OFDM symbol. Where [0, fl) subcarriers form a subband, and there are 3 layers of data to be transmitted on the subband, and each layer of data is modulated by 256QAM; the [fl, f2) subcarrier forms a subband, There are 2 layers of data to be transmitted on the sub-band, and each layer of data is modulated by 64QAM; the [Ω, β) subcarrier forms a sub-band with 2 layers of data to be transmitted, and each layer of data is transmitted. 16Using 16QAM modulation mode; in the [G, f4] subcarriers constitute a sub-band, only one layer of data to be transmitted on the sub-band, using QPSK modulation mode; where, 0, fl, f2, β, f4 All are subcarrier indexes. The encoded data occupies 2 OFDM symbols, and the [0,] subcarriers in the frequency domain form a subband, and 2 sublayers of data are to be transmitted on the subband, wherein the first layer of data is modulated by 64QAM. The second layer data is modulated by 256QAM; in the frequency domain, the [f2, f4] subcarriers form a subband, and the subband has 2 layers of data to be transmitted, wherein the first layer of data is modulated by QPSK. In this way, the second layer of data is modulated by 16QAM.

After the modulation and mapping are completed, the sender will contain multiple consecutive blocks of one or more transport blocks.

The OFDM symbols form a radio frame that is sent to the receiving user.

One of ordinary skill in the art will appreciate that all or a portion of the above steps may be accomplished by a program instructing the associated hardware, such as a read-only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the above embodiment may be implemented in the form of hardware or in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the protection of the present invention. Wai. In view of the present invention, various other modifications, equivalents, improvements, etc., should be made without departing from the spirit and scope of the invention. It is included in the scope of protection of the present invention.

Industrial applicability

After using the above technical solution, the transmitting end flexibly adjusts the data modulation mode on each layer when performing multi-antenna data transmission, can effectively ensure the quality of data transmission, and obtain the gain of adaptive code modulation, thereby further obtaining Higher throughput and peak speed. Therefore, the present invention has industrial applicability.

Claims

Claim

1. A method for transmitting multi-antenna data, comprising:

Encoding each transport block to be transmitted;

The transmission method according to claim 1, wherein, in each OFDM symbol, the number of layers on each sub-band is not completely the same or completely different.

The transmitting method according to claim 1 or 2, wherein the step of modulating the data obtained by encoding the transport block comprises:

The transmitting method according to any one of claims 1 to 3, wherein the step of assigning the number of layers for each subband of each OFDM symbol comprises:

The transmitting method according to claim 1, wherein the step of encoding each transport block to be transmitted comprises:

The transmitting method according to any one of claims 1 to 4, wherein the transmitting method further comprises: before performing modulation, for each transport block, if it is determined that the data to be modulated is insufficient after being modulated and mapped To occupy an integer number of OFDM symbols, the padding bits of the corresponding number of bits are added after the data to be modulated, and then modulated and mapped, so that the number of bits to be modulated after padding is increased. According to the modulation and mapping, it can occupy an integer number of OFDM symbols.

The transmitting method according to any one of claims 1 to 4, wherein the transmitting method further comprises: after mapping to an integer number of the OFDM symbols, determining that an integer number of the OFDM symbols are not full And filling a corresponding number of padding symbols in an integer number of the OFDM symbols to occupy an integer number of the OFDM symbols.

The transmission method according to claim 3, wherein the modulation method comprises: a quadrature phase shift keying modulation method, a quadrature amplitude modulation method including 16 symbols, and a quadrature amplitude modulation method including 64 symbols. Or a quadrature amplitude modulation scheme containing 256 symbols.

9. The transmitting method according to claim 1, wherein:

The size of the transport block to be transmitted is determined by the packet size of the medium access control layer.

10. A transmission system for multi-antenna data, comprising a first device, a second device, and a third device, wherein:

The transmission system according to claim 10, wherein, in each OFDM symbol, the number of layers on each sub-band is not completely the same or completely different.

The transmitting system according to claim 10 or 11, wherein said second means is arranged to modulate data obtained by encoding the transport block in the following manner:

The transmitting system according to any one of claims 10 to 12, wherein the second device The number of layers allocated for each sub-band of each OFDM symbol is set as follows: According to the spatial rank (Rank) of each sub-band in the OFDM symbol, the number of layers is allocated for each sub-band of each OFDM symbol, and the spatial rank value is high. The maximum number of layers that can be allocated in the sub-band is greater than or equal to the maximum value of the number of layers that can be allocated for the sub-band with a low spatial rank.

The transmitting system according to claim 10, wherein said first means is arranged to encode each transport block to be transmitted in the following manner:

The transmitting system according to any one of claims 10 to 13, wherein:

The second device is further configured to: before performing the modulation, if it is determined that the data to be modulated is insufficient to occupy an integer number of OFDM symbols after being modulated and mapped, the data to be modulated is increased after the data to be modulated After the padding bits of the corresponding number of bits, the modulation and mapping are performed, so that the data to be modulated after the padding is added can be filled with an integer number of OFDM symbols after being modulated and mapped.

The transmitting system according to any one of claims 10 to 13, wherein:

The second device is further configured to: after mapping to an integer number of the OFDM symbols, if it is determined that an integer number of the OFDM symbols are not full, fill the corresponding number of fillers in an integer number of the OFDM symbols Symbol to occupy an integer number of the OFDM symbols.