WO2011015065A1

WO2011015065A1 - Sending method for reference signals

Info

Publication number: WO2011015065A1
Application number: PCT/CN2010/072182
Authority: WO
Inventors: 戴博; 郁光辉; 陈艺戬; 杨勋
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-08-07
Filing date: 2010-04-26
Publication date: 2011-02-10
Also published as: CN101626620A; CN101626620B

Abstract

The present invention discloses a sending method for reference signals, and the reference signals are used for demodulation in long term evolution-advanced system. The sending method includes that: the reference signals corresponding to each layer are divided into one or multiple groups; the reference signals in each group are different from each other; each reference signal in the same group are loaded on the same resources by code division multiplexing; physical time-frequency resources taken by the reference signals in the different groups are different from each other. The present invention provides the layer-based sending method for the reference signals. The sending method can ensure the transmission performance while ensuring the less overhead of the reference signals as much as possible, and can be well compatible with an existed LTE system, thereby realizing high order MIMO transmission, and improving overall performance of the system.

Description

Method for transmitting reference signal

Technical field

The present invention relates to a higher-level evolution (Advanced Advancements for E-UTRA or Long Term Evolution-Advanced (LTE-A)) wireless communication system, and more particularly to a method for transmitting a reference signal for demodulation in an LTE-A system.

Background technique

Multiple-Input Multiple-Output (MIMO) technology can increase system capacity, improve transmission performance, and integrate well with other physical layer technologies, thus becoming the next three generations (Beyond 3rd Generation, B3G) and The key technology of 4th generation (4G) mobile communication system. However, when the channel correlation is strong, the diversity gain and multiplexing gain brought by the multipath channel are greatly reduced, resulting in a significant drop in the performance of the MIMO system. In recent years, a new MIMO precoding method is proposed, which is an efficient MIMO multiplexing method, which converts MIMO into multiple independent virtual channels through precoding processing at the transceiver end. Because the effect of channel correlation is effectively eliminated, the precoding technique ensures the stability performance of the MIMO system in various environments. The Long Term Evolution (LTE) system is an important program of the 3rd Generation Partnership Project (3GPP). Figure 1 (a) and Figure 1 (b) are schematic diagrams of the frame structure of the Frequency Division Duplex (FDD) mode and the Time Division Duplex (TDD) mode of the LTE system, respectively. In the frame structure of the FDD mode shown in FIG. 1( a ), a 10 ms radio frame is composed of twenty slots (lengths) of lengths of 0.5 ms and slots 0 to 19, and slots 2i and The slot 2i+1 forms a subframe i of length 1 ms. In the frame structure of the TDD mode shown in FIG. 1(b), a 10 ms radio frame is composed of two half frames of 5 ms length, and one field contains 5 lengths of 1 ms. Subframe (frame). The subframe i consists of two slots 2ι and slot 2i+1 that are 0.5 ms long. In the two frame structures, when the system uses the Normal Cyclic Prefix (Normal CP), one time slot contains 7 lengths of uplink symbols or downlink symbols; when the system uses extended CP, one time slot contains 6 Up or down symbols of length. The above symbols are Orthogonal Frequency Division Multiplexing (OFDM) symbols. One Resource Element (RE) is one subcarrier on one OFDM symbol, and one downlink resource block (RB) consists of 12 consecutive subcarriers and 7 consecutive (6 when using extended cyclic prefix) The OFDM symbol is composed of 180 kHz in the frequency domain and a time slot of a general time slot in the time domain, as shown in FIG. When resource allocation is performed, the LTE system allocates resources blocks as a basic unit. The LTE system supports 4-antenna MIMO applications, and the corresponding antenna port #0, antenna port #1, antenna port #2, and antenna port #3 adopt a full-bandwidth cell-specific reference signal (CRS) method. When the cyclic prefix is a regular cyclic prefix, the location of the cell-specific reference signal in the physical resource block is as shown in Figure 3(a). When the cyclic prefix is an extended cyclic prefix, the location of the cell-specific reference signal in the physical resource block is as shown in Figure 3(b). In Fig. 3) and Fig. 3(b), the abscissa 1 indicates the sequence number of the subframe on the OFDM symbol, C, C ₂ , C ₃ and C ₄ , corresponding to the cell-specific reference signal logical port #0, logical port #1, logical port #2 and logical port #3. In addition, there is a user-specific reference signal (UE-specific reference signals), and the reference signal is transmitted only in a time-frequency domain location where the user-specific Physical downlink shared channel (PDSCH) is located. . The cell-specific reference signal function includes downlink channel quality measurement and downlink channel estimation (demodulation).

LTE-A is an evolved version of LTE Release-8. In addition to meeting or exceeding all relevant requirements of 3GPP TR 25.913 : "equrements for Evolved Universal Telecommunication Radio Access (E-UTRA) and Evolved Universal Mobile Telecommunications System ( UMTS ) Terrestrial Radio Access Network ( E-UTRAN )" Or exceed the requirements of IMT-Advanced proposed by ITU-R. The requirements for backward compatibility with LTE Release-8 refer to: LTE Release-8 terminals can work in LTE-Advanced networks; LTE-Advanced terminals can work in LTE Release-8 networks. In addition, LTE-Advanced should be able to operate in different spectrum configurations, including a wider spectrum configuration than LTE Release-8 (eg, 100 MHz continuous spectrum resources) to achieve higher performance and target peak rates. Since the LTE-Advanced network needs to be able to access the LTE user, its operating band needs to cover the current LTE frequency band, and there is no allocated continuous transmission bandwidth of 100 MHz in this frequency band. Therefore, a direct technology that LTE-Advanced needs to solve is to aggregate several continuous component carrier frequencies (spectrums) distributed in different frequency bands by using component carrier technology to form a 100 MHz bandwidth that can be used by LTE-Advanced. That is, for the aggregated spectrum, it is divided into n component carrier frequencies (spectrums), and the spectrum in each component carrier frequency (spectrum) is continuous. In the LTE-Advanced demand research report proposed in September 2008, TR 36.814 V0.1.1, it has been clarified that the LTE-Advanced downlink can support up to 8 antennas. At the 56th meeting of the 3GPP in February 2009, LTE-Advanced defined LTE-Advanced for applications supporting 8-antenna and Coordinated Multiple Point (CoMP), dual-beamforming (beamforming) and other technologies. The basic design framework of Advanced downlink reference signal (Way forward) defines the downlink reference signal for LTE-Advanced operation as two types of reference signals: reference signal for PDSCH demodulation and channel status information (CSI). The generated reference signal, and the reference signal for PDSCH demodulation is transmitted based on the layer, and each layer corresponds to one reference signal. In the LTE-Advanced system, the maximum number of layers that can be supported is 8. In the existing solution, the reference signals designed are mostly based on the common reference signal of the antenna port, and one, two and four layers of reference signals, and there are no more than four layers based on the layer reference signal transmission method. In view of this, it is necessary to provide a method for transmitting a reference signal to accommodate transmission requirements of layer-by-layer reference signals of more than four layers.

SUMMARY OF THE INVENTION The technical problem to be solved by the present invention is to provide a method for transmitting a reference signal for demodulation in an advanced long term evolution system. In order to solve the above technical problem, the present invention provides a method for transmitting a reference signal, where the reference signal is used for demodulation in an advanced long-term evolution system, and the method includes: dividing a reference signal corresponding to each layer into one or more Groups, so that the reference signals included in each group are different from each other, the resources occupied by the reference signals in the same group are the same, and the reference signals in different groups occupy different physical time-frequency resources; and the reference signals in the same group It is carried on the same resource by means of code division multiplexing. The method further includes: when the number of layers of the reference signal is h, sequentially transmitting the first h reference signals in a time-frequency domain location where the user-specific physical shared channel is located. The layer of the reference signal has 8 layers, and the reference signals corresponding to the layers are sequentially reference signal #0 of layer 1, reference signal #1 of layer 2, reference signal #2 of layer 3, reference signal of layer 4# 3. Reference signal #4 of layer 5, reference signal #5 of layer 6, reference signal #6 of layer 7, and reference signal #7 of layer 8; the method further comprises: setting four orthogonal frequency division multiplexing ( OFDM) symbol, mapping an 8-layer reference signal onto the four OFDM symbols; wherein, the four OFDM symbols are respectively: a first OFDM symbol of the first time slot of the subframe and a second to last An OFDM symbol and a first OFDM symbol and a second to last OFDM symbol of the second slot; or a first OFDM symbol and a second to last OFDM symbol and a second of the first slot in the subframe The second last OFDM symbol and the fourth last OFDM symbol of the time slot; or, when the cyclic prefix in the subframe is a regular cyclic prefix, the four OFDM symbols are: the first time slot in the subframe Fourth OFDM symbol and sixth OFDM symbol and fourth and sixth OFD of the second slot Or the fourth OFDM symbol and the seventh OFDM symbol of the first slot in the subframe and the third OFDM symbol and the sixth OFDM symbol of the second slot. In the grouping step, the reference signals corresponding to the layers are divided into four groups, group 1, group 2, group

3 and group 4, each group contains 2 reference signals; wherein group 1 includes reference signal #0 and reference signal #4 in turn, group 2 includes reference signal #1 and reference signal #5 in sequence, and group 3 includes reference signal in turn. 2 and reference signal #6, and group 4 in turn contain references Signal #3 and reference signal #7; or, group 1 includes reference signal #0 and reference signal #7 in sequence, group 2 includes reference signal #1 and reference signal #6 in sequence, and group 3 sequentially includes reference signal #2 and reference signal #5, and group 4 sequentially includes reference signal #3 and reference signal #4; or, group 1 sequentially includes reference signal #0 and reference signal #6, and group 2 includes reference signals in sequence.

#1 and reference signal #7, group 3 includes reference signal #2 and reference signal #4 in turn, and group 4 includes reference signal #3 and reference signal #5 in sequence. The orthogonal code used in the step of carrying the reference signals in the same group by means of code division multiplexing on the same resource is: the orthogonal code of the first reference signal of each of the four groups is {1 , 1 } , the orthogonal code of the second reference signal of each group is {1 , -1}. The mapping comprises: sequentially mapping the reference signals in the group 1 to the first OFDM symbol and the third OFDM symbol of the four OFDM symbols, occupying 3 subcarriers in the frequency domain; The reference signals in the group 2 are sequentially mapped to the second OFDM symbol and the fourth OFDM symbol of the four OFDM symbols, occupying the same three subcarriers in the frequency domain as the reference signal in the group 1. And mapping the reference signals in the group 3 to the first OFDM symbol and the third OFDM symbol of the four OFDM symbols, occupying a frequency difference from the reference signal in the group 1 Subcarriers; and sequentially mapping the reference signals in the group 4 to the second of the four OFDM symbols

On the OFDM symbol and the fourth OFDM symbol, the same three subcarriers as the reference signal in Group 3 are occupied in the frequency domain. The three subcarriers occupied by the reference signal in the group 1 are: the first, sixth, and eleventh subcarriers in the physical resource block, and the three subcarriers occupied by the reference signal in the group 3 are: the physics The second, seventh, and twelfth subcarriers in the resource block; or, the three subcarriers occupied by the reference signal in the group 1 are: the first, fifth, and ninth subcarriers in the physical resource block The three subcarriers occupied by the reference signal in the group 3 are: The second, sixth, and tenth subcarriers in the physical resource block; or, the three subcarriers occupied by the reference signal in the group 1 are: first, fifth, and ninth in the physical resource block The subcarriers, the three subcarriers occupied by the reference signal in the group 3 are: the third, seventh and eleventh subcarriers in the physical resource block. The mapping comprises: sequentially mapping the reference signals in the group 1 to the first OFDM symbol and the third OFDM symbol of the four OFDM symbols, occupying 3 subcarriers in the frequency domain; The reference signals in the group 2 are sequentially mapped to the first OFDM symbol and the third OFDM symbol of the four OFDM symbols, and occupy three subcarriers different from the reference signal in the group 1 in the frequency domain. And mapping the reference signals in the group 3 to the second OFDM symbol and the fourth OFDM symbol of the four OFDM symbols, occupying the same three subcarriers in the frequency domain as the reference signal in the group 1. ; as well as

The reference signals in the group 4 are sequentially mapped onto the second OFDM symbol and the fourth OFDM symbol of the four OFDM symbols, occupying the same three subcarriers in the frequency domain as the reference signals in the group 2. The three subcarriers occupied by the reference signal in the group 1 are: the first, sixth, and eleventh subcarriers in the physical resource block, and the three subcarriers occupied by the reference signal in the group 2 are: The second, seventh, and twelfth subcarriers in the physical resource block; or, the three subcarriers occupied by the reference signal in the group 1 are: first, fifth, and Nine subcarriers, the three subcarriers occupied by the reference signal in the group 2 are: the second, sixth, and tenth subcarriers in the physical resource block; or, the reference signal in the group 1 is occupied by 3 The subcarriers are: the first, fifth, and ninth subcarriers in the physical resource block, and the three subcarriers occupied by the reference signal in the group 2 are: the third and seventh sums in the physical resource block. The eleventh subcarrier. The mapping includes: sequentially mapping the reference signals in the group 1 to the first one of the four OFDM symbols Omitting 3 subcarriers in the frequency domain on the OFDM symbol and the third OFDM symbol; sequentially mapping the reference signals in the group 2 to the second OFDM symbol and the fourth OFDM symbol in the four OFDM symbols Up, occupying 3 subcarriers different from the reference signal in the group 1 in the frequency domain; sequentially mapping the reference signals in the group 3 to the first one of the four OFDM symbols

And omitting, on the OFDM symbol and the third OFDM symbol, three subcarriers identical to the reference signal in the group 2 in the frequency domain; and sequentially mapping the reference signals in the group 4 into the four OFDM symbols On the second OFDM symbol and the fourth OFDM symbol, the same three subcarriers as the reference signal in Group 1 are occupied in the frequency domain. The three subcarriers occupied by the reference signal in the group 1 are: first, sixth, and eleventh subcarriers in the physical resource block, and the three subcarriers occupied by the reference signal in the group 2 are: the physics The second, seventh, and twelfth subcarriers in the resource block; or, the three subcarriers occupied by the reference signal in the group 1 are: the first, fifth, and ninth subcarriers in the physical resource block The three subcarriers occupied by the reference signal in the group 2 are: the second, sixth, and tenth subcarriers in the physical resource block; or, the three subcarriers occupied by the reference signal in the group 1 are : the first, fifth, and ninth subcarriers in the physical resource block, and the three subcarriers occupied by the reference signal in the group 2 are: third, seventh, and eleventh in the physical resource block Or, the three subcarriers occupied by the reference signal in the group 1 are: the first, sixth, and eleventh subcarriers in the physical resource block, and the reference signal in the group 2 is occupied. The three subcarriers are: Second, seventh, and twelfth subcarrier block. In the grouping step, the reference signals corresponding to the layers are divided into two groups, group 1 and group 2, each group comprising four reference signals, wherein the group 1 includes the reference signal #0 and the reference signal #1 in sequence. , reference signal #4 and reference signal #5, group

2 sequentially includes reference signal #2, reference signal #3, reference signal #6, and reference signal #7; or, group 1 sequentially includes reference signal #0, reference signal #1, reference signal #6, and reference signal #7, Group 2 includes reference signal #2, reference signal #3, reference signal #4, and reference signal #5 in sequence; or, group 1 includes reference signal #0, reference signal #1, reference signal #4, and reference signal in sequence. #6, Group 2 includes reference signal #2, reference signal #3, reference signal #5, and reference signal #7 in sequence; or, group 1 includes reference signal #0, reference signal #1, reference signal #5, and reference signal in sequence. #7, Group 2 includes reference signal #2, reference signal #3, reference signal #4, and reference signal #6 in sequence; or, group 1 includes reference signal #0, reference signal #1, reference signal #4, and reference signal in sequence. #7, Group 2 includes reference signal #2, reference signal #3, reference signal #5, and reference signal #6 in sequence; or, group 1 includes reference signal #0, reference signal #1, reference signal #5, and reference signal in sequence. #6, Group 2 includes reference signal #2, reference signal #3, reference signal #4, and reference signal #7 in sequence; or, group 1 includes reference signal #0, reference signal #2, reference signal #4, and reference signal in sequence.

#6, Group 2 contains reference signal #1, reference signal #3, reference signal #5 and reference signal #7 in sequence.

The orthogonal code used in the step of carrying the reference signals in the same group by means of code division multiplexing on the same resource is: the orthogonal code of the first reference signal of each of the two groups For {1, 1, 1, 1}, the orthogonal code of the second reference signal of each group is {1, -1, 1, -1}, and the orthogonal code of the third reference signal of each group is used. The orthogonal codes used for {1, 1, -1, -1}, and the fourth reference signal of each group are -1, -1, 1};

Or, the first reference signal of each of the two groups adopts an orthogonal code of {1, 1, 1,

1}, the orthogonal code of the second reference signal of each group is u, -1, 1, -1}, and the orthogonal code of the third reference signal of each group is {1, -1, -1 , 1}, and the fourth reference signal of each group uses an orthogonal code of {1, 1, -1, -1}

The mapping comprises: sequentially mapping the reference signals in the group 1 to the four OFDM symbols, occupying 3 subcarriers in a frequency domain; and sequentially mapping the reference signals in the group 2 to the On the four OFDM symbols, three subcarriers different from the reference signal in the group 1 are occupied in the frequency domain. The three subcarriers occupied by the reference signal in the group 1 are: the first, sixth, and eleventh subcarriers in the physical resource block, and the three subcarriers occupied by the reference signal in the group 2 are: The second, seventh, and twelfth subcarriers in the resource block; or, the reference signal in the group 1 occupies the first, fifth, and ninth subcarriers in the physical resource block, and the group 2 The reference signal occupies the second, sixth and tenth subcarriers in the physical resource block;

Or, the reference signal in the group 1 occupies the first, fifth, and ninth subcarriers in the physical resource block, and the reference signal in the group 2 occupies the third, seventh, and tenth in the physical resource block. One subcarrier.

The mapping comprises: sequentially mapping the reference signals in the group 1 to the first OFDM symbol and the third OFDM symbol of the four OFDM symbols, occupying 6 subcarriers in the frequency domain; Mapping the reference signals in the group 2 to the second OFDM symbol and the fourth OFDM symbol of the four OFDM symbols, and occupying the same 6 sub-bands in the frequency domain as the reference signal in the group 1. Carrier. The six subcarriers are: first, second, sixth, seventh, eleventh and twelfth subcarriers in the physical resource block, or first, second, fifth, sixth, ninth and The tenth subcarrier. In the grouping step, the reference signals corresponding to the layers are divided into one group, and the group includes eight reference signals;

The orthogonal code used in the step of carrying the reference signals on the same resource by means of code division multiplexing is: The orthogonal code used in the test signal #0 is {1, 1, 1, 1, 1, 1 , 1, 1};

The orthogonal code used for the test signal #1 is {1, -1, 1, -1 1, -1, 1, - The orthogonal code used for the test signal #2 is {1, -1, -1, 1 1, -1, -1, the orthogonal code used in the test signal #3 is {1, 1, -1, -1 1, 1, - 1, - The orthogonal code used in the test signal #4 is {1, 1 , 1, 1, -1, -1, - 1, - The orthogonal code used in the test signal #5 is {1, -1, 1, -1 -1, 1, -1, The orthogonal code of reference signal #6 is {1, -1, -1, 1, -1, 1, 1, -1}; and the orthogonal code of reference signal #7 is {1, 1, -1, -1, -1, -1, 1, 1}.

The mapping comprises: sequentially mapping reference signals in the group to the four OFDM symbols, occupying 6 subcarriers in a frequency domain; and the 6 subcarriers are first, second, sixth, seventh The eleventh and twelfth subcarriers are either the first, second, fifth, sixth, ninth and tenth subcarriers. The reference signal data mapped on the carrier of the same frequency domain position in different time domain symbols in the same group is the same.

The layer has 8 layers, and the reference signals corresponding to the layers are sequentially reference signals #k of layer k; k are 0, 1, 2, 3, 4, 5, 6 and 7 respectively; wherein the reference signal# The sequence of k is generated according to the following formula: r(m) = -^=(l-2-c(2m)) + j-^=(l-2-c(2m + l)),m = 0,l ,...,Ll where: k are 0, 1, 2, 3, 4, 5, 6 and 7 respectively;

L is the sequence length required for the reference signal #k; the pseudo-random sequence _c (o is generated according to the following formula: c(i) = (χ _λ (ί + Ν _σ ) + x ₂ (i + N _C )) mod 2

x, ( + 31) = ( , ( + 3 ) + x, ( ) ) mod 2

x ₂ (i + 31) = ( ₂ ( + 3) + x ₂ (i + 2) + x ₂ (i + 1) + x ₂ (;')) mod 2 where:

N _c =1600; (0) = 1, (") = 0, « = 1, 2, ..., 30 ;

3⁄4 is generated according to a pseudo-random sequence initial value c _mit 2"; ^C mi _t is an integer greater than or equal to zero. by

rO) mapping the sequence r( ) of the reference signal to the antenna logical port p, the OFDM symbol /, the subcarrier A, where: α(, _7·) is an orthogonal code factor, and

=0 and _/' = 0, 1, 2 or 3, a(i,j) = V,

= 1 and = 0 or = 2, a(i, y) = 1;

= lJL j = \or y = 3 H†, a(iJ) = -\;

=2 and j' = 0or_/ = l, a(ij) = l; i = 2JL j = 2or y = 30†, a(i,j) = -\; i =3 JL j = 0or j = 30 †, a(ij) = \;

i = 3Hj = lorj = 2 H, O — 1.

Compared with the prior art, the method for transmitting a layer-based reference signal provided by the present invention ensures minimum transmission of reference signal overhead while ensuring transmission performance, and can be well compatible with existing LTE systems. Thus, high-order MIM0 transmission is realized, which supports the use of corresponding technologies and improves the overall performance of the system.

1(a) is a schematic diagram of a frame structure of an LTE system FDD mode; FIG. 1(b) is a schematic diagram of a frame structure of an LTE system TDD mode; FIG. 2 is a schematic diagram of a physical resource block of an LTE system with a system bandwidth of 5 MHz; 3 (a) Schematic diagram of the location of the public reference signal in the physical resource block for the conventional CP; Figure 3 (b) is the location of the public reference signal in the physical resource block when the CP is extended; Figure 4 (a) to Figure 4 ( d) is a schematic diagram of the carrier position of the reference signal in the resource block according to the first embodiment of the method of the present invention; FIG. 5 (a) to FIG. 5 (d) of the reference signal of the second embodiment of the method of the present invention are carried in the resource block Figure 6 (a) and Figure 6 (b) is a schematic diagram of the carrier position of the reference signal in the resource block according to the third embodiment of the method of the present invention; Figure 7 (a) and Figure 7 (b) is the method of the present invention FIG. 8(a) and FIG. 8(b) are schematic diagrams showing the carrier position of a reference signal in a resource block according to a fifth embodiment of the method of the present invention; FIG. 9(a) to FIG. FIG. 9(h) is a schematic diagram of a carrier position of a reference signal in a resource block according to a sixth embodiment of the method of the present invention.

Preferred embodiment of the invention

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings and embodiments, in which the present invention can be applied to the technical problems, and the implementation of the technical effects can be fully understood and implemented. In the method for transmitting a reference signal generated by the channel state information for the LTE-Advanced system, the reference signal corresponding to each layer is recorded as the reference signal #0 of layer 1, the reference signal #1 of layer 2, and the layer 3 Reference signal #2, reference signal #3 of layer 4, reference signal #4 of layer 5, reference signal #5 of layer 6, reference signal #6 of layer 7, reference signal #7 of layer 8, where the base station will The reference signals are divided into several groups, and the reference signals included in each group are different from each other. The resources occupied by the reference signals in the same group are the same. The reference signals of different groups occupy different physical time-frequency resources, and the reference signals in the same group pass. The code division multiplexing method is carried on the same resource. 4 to FIG. 8 are diagrams showing respective embodiments of a reference signal transmission method according to the present invention, respectively showing specific carrier positions of a layer-based reference signal in its corresponding resource block. 4 to 8, reference numerals 7; τ _Ί , r ₃ , τ ₄ , r ₅ , τ ₆ , r ₇ and r ₈ respectively correspond to the reference signal #0 of layer 1 and the reference signal #1 of layer 2. Reference signal #2 of layer 3, reference signal #3 of layer 4, reference signal #4 of layer 5, reference signal #5 of layer 6, reference signal #6 of layer 7, and reference signal #7 of layer 8. The reference signal is transmitted only in the time-frequency domain location where the user-specific physical shared channel is located. The sequence of the reference signal #k (k=0 1, 2 3, 4 5, 6 7) is generated as follows: Equation (1)

among them:

L is the sequence length required for the reference signal #k; the pseudo-random sequence is generated as follows: c(i) = (x _] (i + N _c ) + x ₂ (i + N _C )) mod 2 Equation (2) χ _λ (/ + 31) = ( , (? + 3) + , ()) mod 2 Equation (3) x ₂ (z + 31) = [x ₂ (i + 3) + x ₂ (i + 2) + x ₂ (i + 1) + x ₂ (z)) mod 2 (4)

N _c =1600;

x ₁ ( ) = \,x _l (n) = , n = \,2,...,30;

χ ₂ According to the pseudo-random sequence initial value c _init =H° ₌ . ^0) '2' is generated;

^C mit is a positive integer greater than or equal to zero;

The c _init can be calculated according to equation (5), and the pseudo-random sequence c(i) is generated by substituting equations (2), (3), and (4):

Equation (5) n _% is the slot index in one radio frame; N is the identifier of the cell;

3⁄4m is a user-specific logo;

Lx" is the next rounding operation.

However, c _init can also be generated in other ways, not limited to equation (5). Map the reference signal (m') to the antenna logical port _P , OFDM symbol /, subcarrier A = a(i, j) xr _{l rh} {m ') , a(i, J) is positive as shown in the following table Crossing factor: Where r(m is equivalent to the original sequence, r _Lt (m ') is a sequence intercepted from the original sequence mapped to the physical resource, and how to intercept is determined by the relationship between / w' and m, 0 <= if; = then , rim and (m ') are the same; i [a(i , 0), a(i, 1), a(i, 2), a(], 2)]

0 11, 1, 1, 1]

1 |1, ■1, 1, ■1]

2 11, 1, ■1, ■1]

|1, ■1, •1, 1] or the orthogonal code factor can also be described as:

=0 and _ = 0, 1, 2 or 3, "(, ·, =1;

=1 and = 0 or = 2, 7) = 1;

=1 and = \or y = 3Ht, a{i,j) = ~ ;

=2 and _/ = 0or _/' = 1, when, 7) = 1;

=2 and _ = 2 or = 3, ^a j,f) =- .

=3 and _/ = 0 or = 3, α(, ) = 1;

=3 and _/ = 1 or = 2, a{i ) = ~l.

It should be noted that the above r( ) indicates the manner in which the sequence is generated, where (“how to map the elements of the sequence to the physical resources. When the number of layers is h, only the corresponding reference signal #0, reference signal# is transmitted. 1, ..., reference signal #hl, other reference signals are not transmitted. Four OFDM symbols are set, and an 8-layer reference signal is mapped onto the four OFDM symbols, respectively: the first one in the subframe a first OFDM symbol and a penultimate OFDM symbol of the slot, a first OFDM symbol of the second slot, and a second to last OFDM symbol; or a reciprocal of the first slot in the subframe OFDM symbols and the penultimate OFDM symbol, The second last OFDM symbol of the second time slot and the fourth last OFDM symbol; or when the cyclic prefix in the subframe is a regular cyclic prefix, the four OFDM symbols may be the fourth of the first time slot in the subframe OFDM symbols and a sixth OFDM symbol, a fourth OFDM symbol of the second slot, and a sixth OFDM symbol; or when the cyclic prefix in the subframe is a regular cyclic prefix, the four OFDM symbols may be in a subframe The fourth OFDM symbol and the seventh OFDM symbol of the first slot, the third OFDM symbol of the second slot, and the sixth OFDM symbol.

When grouping all reference signals, all 8 layers of reference signals can be divided into 2 groups, each group containing 4 reference signals, wherein the reference signals included in each group are: Group 1 contains reference signals #0, #1 in sequence. , #4 and #5, group 2 contains reference signals #2, #3,

#6与 #7; Or,

Group 1 contains reference signals #0, #1, #6, and #7 in sequence, and group 2 contains reference signals #2, #3, in turn.

#4和 #5; Or,

Group 1 contains reference signals #0, #1, #4, and #6 in turn, and group 2 contains reference signals #2, #3, in turn.

#5和#7; Or,

Group 1 contains reference signals #0, #1, #5, and #7 in turn, and group 2 contains reference signals #2, #3, in turn.

#4和 #6; Or,

Group 1 contains reference signals #0, #1, #4, and #7 in sequence, and group 2 contains reference signals #2, #3, #5, and #6;

Group 1 contains reference signals #0, #1, #5, and #6 in turn, and group 2 contains reference signals #2, #3, in turn.

#4和 #7; Or,

Group 1 contains reference signals #0, #2, #4, and #6 in turn, and group 2 contains reference signals #1, #3, in turn.

#5 and #7. When the order of the reference signals in the group is arranged as described above, the first reference signal in each group corresponds to the orthogonal code is {1, 1 , 1 , 1} , and the second reference signal corresponds to the orthogonal code is {1 , - 1 , 1 , -1} , The third reference signal corresponds to an orthogonal code of {1, 1, -1, -1}, and the fourth reference signal corresponds to an orthogonal code of {1, -1, -1, 1}; or, the first in the group The reference signals correspond to orthogonal codes {1, 1, 1, 1}, the second reference signals correspond to orthogonal codes {1, -1, 1, -1}, and the third reference signals correspond to orthogonal codes. {1, -1, -1, 1}, the fourth reference signal in the group corresponds to the orthogonal code {1, 1, -1, -1} _0. When all 8 layers of reference signals are divided into 2 groups, they can be divided into 2 groups. It is a typical scenario of the first scene and the second scene as described below. The reference signals in the first scene group 1 are sequentially mapped to the four OFDM symbols set as described above, occupying 3 subcarriers in the frequency domain; the reference signals in the group 2 are sequentially mapped to the aforementioned four OFDM symbols, in the frequency domain. The three subcarriers occupying the reference signal in the group 1 are occupied, wherein: the reference signal in the group 1 occupies the first, sixth, and eleventh subcarriers in the physical resource block, and the reference signal in the group 2 occupies the physical resource. The second, seventh, and twelfth subcarriers in the block; or, the reference signal in the group 1 occupies the first, fifth, and ninth subcarriers in the physical resource block, and the reference signal in the group 2 occupies the physical resource block The second, sixth, and tenth subcarriers in the medium; or, the reference signal in the group 1 occupies the first, fifth, and ninth subcarriers in the physical resource block, and the reference signal in the group 2 occupies the physical resource block Third, seventh, eleventh subcarrier. The reference signal data mapped on the carriers of the same frequency domain position in different time domain symbols in the same group is the same. In the first embodiment corresponding to the first scenario, in the embodiment, the number of layers of the reference signal is 8, and the reference signal #0, the reference signal #1, and the reference signal #7 are respectively transmitted. The 8-layer reference signals are divided into two groups, each of which contains four reference signals. The reference signals included in group 1 are reference signals #0, #1, #4, and #6, respectively, and the reference signals included in group 2 are reference signals #2, #3, #5, and #7, respectively. When the order of the reference signals in the two groups is arranged as described above, the reference signal #0 and the reference signal #2 correspond to the orthogonal code {1, 1, 1, 1}, and the reference signal #1 and the reference signal #3 correspond to the orthogonal code. For {1, -1, 1, -1}, reference signal #4 and reference signal #5 correspond to orthogonal codes of {1, 1, -1, -1}, reference signal #6 and reference signal #7 correspond to positive Cross code is {1, -1, -1 , 1}.

Reference signal #0, located on the first, sixth, eleventh subcarriers of the penultimate symbol of the first slot in the subframe and the first, sixth, eleventh of the first symbol of the last On the first subcarrier, and the first, sixth, eleventh subcarriers of the penultimate symbol of the second slot, and the first, sixth, eleventh subcarriers of the first symbol of the last Upper; corresponding orthogonal code is {1, 1 , 1 , 1}. Reference signal #1, located on the first, sixth, eleventh subcarriers of the second to last symbol of the second slot in the subframe and the first, sixth, eleventh of the first symbol of the last On the first subcarrier, and the first, sixth, eleventh subcarriers of the penultimate symbol of the second slot, and the first, sixth, eleventh subcarriers of the first symbol of the last Upper; The corresponding orthogonal code is {1, -1, 1, -1 }.

Reference signal #2, located on the second, seventh, twelfth subcarriers of the penultimate symbol of the first slot in the subframe and the second, seventh, and twelfth subfields of the first symbol of the last On the carrier, and on the second, seventh, and twelfth subcarriers of the second to last symbol of the second time slot, and on the second, seventh, and twelfth subcarriers of the last symbol; The code is {1, 1 , 1 , 1}. Reference signal #3, located on the second, seventh, twelfth subcarriers of the second to last symbol of the second slot in the subframe and the second, seventh, and twelfth subfields of the first symbol On the carrier, and on the second, seventh, and twelfth subcarriers of the second to last symbol of the second time slot, and on the second, seventh, and twelfth subcarriers of the last symbol; The code is {1 , -1 , 1 , -1 }.

Reference signal #4, located on the first, sixth, eleventh subcarriers of the penultimate symbol of the first slot in the subframe and the first, sixth, eleventh of the first symbol of the last On the first subcarrier, and the first, sixth, eleventh subcarriers of the penultimate symbol of the second slot, and the first, sixth, eleventh subcarriers of the first symbol of the last Upper; The corresponding orthogonal code is {1, 1 , -1 , -1 }. Reference signal #5, located on the second, seventh, twelfth subcarriers of the penultimate symbol of the first slot in the subframe and the second, seventh, and twelfth subfields of the first symbol of the last On the carrier, and on the second, seventh, and twelfth subcarriers of the second to last symbol of the second time slot, and on the second, seventh, and twelfth subcarriers of the last symbol; The code is {1, 1 , -1 , -1 }. Reference signal #6, located on the first, sixth, eleventh subcarriers of the penultimate symbol of the first slot in the subframe and the first, sixth, eleventh of the first symbol of the last On the subcarriers, and on the first, sixth, eleventh subcarriers and the last number of the second to last symbols of the second slot On the first, sixth, and eleventh subcarriers of a symbol; the corresponding orthogonal code is {1, -1, -1, 1}. Reference signal #7, located on the second, seventh, twelfth subcarriers of the penultimate symbol of the first slot in the subframe and the second, seventh, and twelfth subfields of the first symbol of the last On the carrier, and on the second, seventh, and twelfth subcarriers of the second to last symbol of the second time slot, and on the second, seventh, and twelfth subcarriers of the last symbol; The code is {1, -1, -1, 1}.

Mapping the reference signal sequence ^ ¹ ) to the antenna logical port pOFDM symbol/upper subcarrier; on t, for CP: when regular cyclic prefix

3⁄4 =^ ') ^χ ^ (^')

If n _s mod 2 = 0

[2,3 if n _s mod 2 = 1

I'

0,1,. •,3NTM-1 extended cyclic prefix A:' + 12x« _PRB

(7w'mod3)x5 ifpe{0,l,4,6}

k':

l + (ra'mod3)x5 {2,3,5,7}

4 r=o

5 l' = \

/ =

4 l' = 2 if n _s mod 2 = 0

l'=

If n _s mod 2 = 1

among them:

« _PRB is the resource block index of the corresponding PDSCH, and N^ ^SCH is the number of resource blocks occupied by the corresponding PDSCH. When the CP is a regular cyclic prefix, the position of the reference signal in the physical resource block is as shown in Fig. 4(a) to Fig. 4(d), where Fig. 4(a) to Fig. 4(d) correspond to the reference signal# 0 to the time-frequency position and orthogonal code of the reference signal #7, and the orthogonal code mapping method.

The reference signal in the second scene group 1 is sequentially mapped to the first of the four OFDM symbols set as described above.

OFDM symbol and the third OFDM symbol occupy 6 subcarriers in the frequency domain; the reference signals in group 2 are sequentially mapped to the second OFDM symbol and the fourth OFDM symbol of the above four OFDM symbols, at the frequency The domain occupies the same 6 subcarriers as the reference signal in Group 1. The foregoing six subcarriers are the first, second, sixth, seventh, eleventh, and twelfth subcarriers in the physical resource block, or are the first, second, fifth, and sixth in the physical resource block. , ninth, tenth, a total of six subcarriers. The mapped reference signal data is the same on the same frequency domain location in the different time domain symbol physical resource blocks in the same group, and the first frequency domain location in the physical resource block and the carrier mapping on the second frequency domain location The reference signal data is the same, and the third frequency domain position in the physical resource block is the same as the reference signal data mapped on the carrier of the fourth frequency domain position, and the fifth frequency domain position and the first in the physical resource block are The reference signal data mapped on the carrier of the six-frequency domain location is the same. In the second embodiment corresponding to the second scenario, in the embodiment, the number of layers of the reference signal is 8, and the reference signal #0, the reference signal #1, and the reference signal #7 are respectively transmitted. The reference signals in group 1 are reference signals #0, #1, #4, and #6, respectively, and the reference signals in group 2 are reference signals #2, #3, #5, and #7, respectively, and the sequence of reference signals in the group. Arranged in the foregoing manner, reference signal #0 and reference signal #2 correspond to orthogonal codes of {1, 1, 1, 1}, and reference signal #1 and reference signal #3 correspond to orthogonal codes of {1, -1, 1 , -1}, reference signal #4 and reference signal #5 correspond to orthogonal codes of {1, 1, -1, -1}, reference signal #6 and reference signal #7 correspond to orthogonal codes of {1, -1 , -1, 1}.

Reference signal #0, located on the first, second, sixth, seventh, eleventh and twelfth subcarriers of the penultimate symbol of the first slot in the subframe, and the second slot On the first, second, sixth, seventh, eleventh and twelfth subcarriers of the penultimate symbol; the corresponding orthogonal code is {1, 1, 1, 1}.

Reference signal #1, located on the first, second, sixth, seventh, eleventh and twelfth subcarriers of the penultimate symbol of the first slot in the subframe, and the second slot On the first, second, sixth, seventh, eleventh and twelfth subcarriers of the penultimate symbol; the corresponding orthogonal code is {1, -1, 1, -1}.

Reference signal #2, located on the first, second, sixth, seventh, eleventh and twelfth subcarriers of the first symbol of the first time slot of the subframe, and the second time slot On the first, second, sixth, seventh, eleventh and twelfth subcarriers of the first symbol of the last sign; the corresponding orthogonal code is {1, 1, 1, 1}. Reference signal #3, located on the first, second, sixth, seventh, eleventh and twelfth subcarriers of the first symbol of the first time slot of the subframe, and the second time slot The first, second, sixth, seventh, eleventh and twelfth subcarriers of the first symbol of the last digit; the corresponding orthogonal code is {1, -1, 1, -1}.

Reference signal #4, located on the first, second, sixth, seventh, eleventh and twelfth subcarriers of the penultimate symbol of the first slot in the subframe, and the second slot On the first, second, sixth, seventh, eleventh and twelfth subcarriers of the penultimate symbol; the corresponding orthogonal code is {1, 1, -1, -1}. Reference signal #5, located on the first, second, sixth, seventh, eleventh and twelfth subcarriers of the last symbol of the first time slot in the subframe, and the second time slot On the first, second, sixth, seventh, eleventh and twelfth subcarriers of the first symbol of the last digit; the corresponding orthogonal code is {1, 1, -1, -1}.

Reference signal #6, located on the first, second, sixth, seventh, eleventh and twelfth subcarriers of the penultimate symbol of the first slot in the subframe, and the second slot On the first, second, sixth, seventh, eleventh and twelfth subcarriers of the penultimate symbol; the corresponding orthogonal code is {1, -1, -1, 1}.

Reference signal #7, located on the first, second, sixth, seventh, eleventh and twelfth subcarriers of the last symbol of the first time slot in the subframe, and the second time slot On the first, second, sixth, seventh, eleventh and twelfth subcarriers of the first symbol of the last digit; the corresponding orthogonal code is -1, -1, i}.

When the cyclic prefix is a regular cyclic prefix, the positions of these reference signals in the physical resource block are as shown in Fig. 5(a) to Fig. 5(d), and Fig. 5(a) to Fig. 5(d) correspond to the reference signals respectively. #0 to the frequency domain position and orthogonal code of the reference signal #7, and the orthogonal code mapping method. It should be noted that, in this embodiment, orthogonal codes in the frequency domain are used, and in other embodiments, orthogonal codes in the time domain are used.

When grouping all reference signals, all 8 layers of reference signals can also be divided into 4 groups, each group containing 2 reference signals, wherein the reference signals contained in each group are: Group 1 contains reference signals #0 and # in turn. 4. Group 2 contains reference signals #1 and #5 in sequence, group 3 contains reference signals #2 and #6 in turn, group 4 contains reference signals #3 and #7 in sequence; or, group 1 contains reference signals #0 and # in turn. 7, group 2 contains reference signals #1 and #6 in turn, group 3 Including reference signals #2 and #5 in sequence, group 4 contains reference signals #3 and #4 in sequence; or, group 1 contains reference signals #0 and #6 in sequence, and group 2 contains reference signals #1 and #7 in sequence, group 3 Including reference signals #2 and #4 in turn, group 4 contains reference signals #3 and #5 in sequence. When the order of the reference signals in each group is arranged as described above, the first reference signal in the group corresponds to the orthogonal code {1, 1}, and the second reference signal corresponds to the orthogonal code {1, -1}. When all 8 layers of reference signals are divided into 4 groups, they can be divided into three typical scenarios as follows: the third scenario, the fourth scenario, and the fifth scenario. The reference signals in the third scene group 1 are sequentially mapped to the first OFDM symbol and the third OFDM symbol of the foregoing four OFDM symbols, occupying 3 subcarriers in the frequency domain; the reference signals in the group 2 are sequentially Mapping to the second OFDM symbol and the fourth OFDM symbol of the four OFDM symbols, occupying the same three subcarriers in the frequency domain as the reference signal in the group 1; the reference signals in the group 3 are sequentially mapped to the four On the first OFDM symbol and the third OFDM symbol, occupying 3 subcarriers different from the reference signal in group 1 in the frequency domain; the reference signals in group 4 are sequentially mapped into the four OFDM symbols On the second OFDM symbol and the fourth OFDM symbol, occupying the same three subcarriers in the frequency domain as the reference signal in group 3, where: the reference signal in group 1 occupies the first and sixth in the physical resource block The eleventh subcarrier, the reference signal in the group 3 occupies the second, seventh, and twelfth subcarriers in the physical resource block; or

The reference signal in group 1 occupies the first, fifth, and ninth subcarriers in the physical resource block, and the reference signal in group 3 occupies the second, sixth, and tenth subcarriers in the physical resource block; Or,

The reference signal in group 1 occupies the first, fifth, and ninth subcarriers in the physical resource block, and the reference signal in group 3 occupies the third, seventh, and eleventh sub-parts in the physical resource block. Carrier. The reference signal data mapped on the carrier of the same frequency domain position in different time domain symbols in the same group is the same.

Third embodiment corresponding to the third scenario In this embodiment, the number of layers of the reference signal is 8, and the reference signal #0, the reference signal #1, and the reference signal #7 are respectively transmitted. The reference signals in group 1 are reference signals #0 and #4, the reference signals in group 2 are reference signals #1 and #5, and the reference signals in group 3 are reference signals #2 and #6, group 4 The reference signals in the order are reference signals #3 and #7 in sequence. Wherein, the reference signals #0, #1, #2, and #3 correspond to orthogonal codes of {1, 1 }, and reference signals #4, #5, #6, and #7 correspond to orthogonal codes of {1, -1}. . Reference signal #0, located on the first, sixth, eleventh subcarriers of the second to last symbol of the first slot in the subframe, and the first of the second to last symbols of the second slot , the sixth, the eleventh subcarrier; the corresponding orthogonal code is {1, 1}. Reference signal #1, located on the first, sixth, eleventh subcarriers of the last symbol of the second time slot in the subframe, and the first of the first symbol of the second time slot , the sixth, the eleventh subcarrier; the corresponding orthogonal code is {1, 1}. Reference signal #2, located on the second, seventh, twelfth subcarriers of the penultimate symbol of the first slot in the subframe, and second, the second to last symbol of the second slot Seventh, the twelfth subcarrier; the corresponding orthogonal code is {1, 1}.

Reference signal #3, located on the second, seventh, twelfth subcarriers of the first symbol of the first time slot of the subframe, and the second symbol of the first symbol of the second time slot Seventh, the twelfth subcarrier; the corresponding orthogonal code is, i } o

Reference signal #4, located on the first, sixth, eleventh subcarriers of the second to last symbol of the first slot in the subframe, and the first of the second to last symbols of the second slot , the sixth, the eleventh subcarrier; the corresponding orthogonal code is {1, -1}. Reference signal #5, located on the first, sixth, eleventh subcarriers of the last symbol of the second time slot in the subframe, and the first of the first symbol of the second time slot , the sixth, the eleventh subcarrier; the corresponding orthogonal code is {1, -1} ο

Reference signal #6 is located on the second, seventh, and twelfth subcarriers of the penultimate symbol of the first slot in the subframe, and second and second of the second to last symbol of the second slot 7. On the twelfth subcarrier; the corresponding orthogonal code is {1, -1}. Reference signal #7, located on the second, seventh, twelfth subcarriers of the first symbol of the first time slot of the subframe, and the second symbol of the first symbol of the second time slot Seventh, tenth On two subcarriers; the corresponding orthogonal code is {1, -1}. When the cyclic prefix is a regular cyclic prefix, the positions of these reference signals in the physical resource block are as shown in Fig. 6(a) and Fig. 6(b), where Fig. 6(a) and Fig. 6(b) correspond to the reference respectively. Time-frequency position and orthogonal code of signal #0 to reference signal #7, and orthogonal code mapping.

The reference signals in the fourth scene group 1 are sequentially mapped to the first OFDM symbol and the third OFDM symbol of the foregoing four OFDM symbols, occupying 3 subcarriers in the frequency domain; the reference signals in the group 2 are sequentially Mapping to the first OFDM symbol and the third OFDM symbol of the four OFDM symbols, occupying 3 subcarriers different from the reference signal in the group 1 in the frequency domain; the reference signals in the group 3 are sequentially mapped to the fourth On the second OFDM symbol and the fourth OFDM symbol, occupying the same 3 subcarriers as the group 1 in the frequency domain; the reference signals in the group 4 are sequentially mapped to the second of the four OFDM symbols On the OFDM symbol and on the fourth OFDM symbol, occupy the same three subcarriers as the group 2 in the frequency domain, where: the reference signal in the group 1 occupies the first, sixth, eleventh in the physical resource block a subcarrier, the reference signal in the group 2 occupies the second, seventh, and twelfth subcarriers in the physical resource block; or the reference signal in the group 1 occupies the first and fifth in the physical resource block , the ninth subcarrier, the reference signal in group 2 Using the second, sixth, and tenth subcarriers in the physical resource block; or, the reference signal in the group 1 occupies the first, fifth, and ninth subcarriers in the physical resource block, in the group 2 The reference signal occupies the third, seventh, eleventh subcarriers in the physical resource block. The reference signal data mapped on the carriers of the same frequency domain position in different time domain symbols in the same group is the same. Fourth Embodiment Corresponding to the Fourth Scenario In this embodiment, the number of layers of the reference signal is 8, and the reference signal #0, the reference signal #1, and the reference signal #7 are respectively transmitted. The reference signals in group 1 are reference signals #0 and #4, group 2 The reference signals in the order are reference signals #1 and #5, the reference signals in group 3 are sequentially referenced to signals #2 and #6, and the reference signals in group 4 are sequentially referenced to signals #3 and #7. Wherein, the reference signals #0, #1, #2, and #3 correspond to orthogonal codes {1, 1}, and the reference signals #4, #5, #6, and #7 correspond to orthogonal codes {1, -1 } . Reference signal #0, located on the first, sixth, eleventh subcarriers of the second to last symbol of the first slot in the subframe, and the first of the second to last symbols of the second slot , the sixth, the eleventh subcarrier; the corresponding orthogonal code is {1, 1}. Reference signal #1, located on the second, seventh, twelfth subcarriers of the penultimate symbol of the first slot in the subframe, and second, the second to last symbol of the second slot Seventh, the twelfth subcarrier; the corresponding orthogonal code is {1, 1}. Reference signal #2, located on the first, sixth, eleventh subcarriers of the last symbol of the first time slot in the subframe, and the first of the first symbol of the second time slot , the sixth, the eleventh subcarrier; the corresponding orthogonal code is {1, 1}. Reference signal #3, located on the second, seventh, twelfth subcarriers of the first symbol of the first time slot of the subframe, and the second symbol of the first symbol of the second time slot Seventh, the twelfth subcarrier; the corresponding orthogonal code is {1, 1}.

Reference signal #4, located on the first, sixth, eleventh subcarriers of the second to last symbol of the first slot in the subframe, and the first of the second to last symbols of the second slot , the sixth, the eleventh subcarrier; the corresponding orthogonal code is {1, -i }.

Reference signal #5, located on the second, seventh, twelfth subcarriers of the penultimate symbol of the first slot in the subframe, and second, the second to last symbol of the second slot Seventh, the twelfth subcarrier; the corresponding orthogonal code is -i

Reference signal #6, located on the first, sixth, eleventh subcarriers of the last symbol of the first time slot in the subframe, and the first of the first symbol of the second time slot , the sixth, the eleventh subcarrier; the corresponding orthogonal code is {1, -1 reference signal #7, the second, seventh, and the first symbol located in the last slot of the first slot in the subframe On the twelve subcarriers, and on the second, seventh, and twelfth subcarriers of the first symbol of the second time slot; the corresponding orthogonal code is {1, -1} When the cyclic prefix is a regular cyclic prefix, the positions of these reference signals in the physical resource block are as shown in Fig. 7(a) and Fig. 7(b), where Fig. 7(a) and Fig. 7(b) correspond to the reference respectively. Time-frequency position and orthogonal code of signal #0 to reference signal #7, and orthogonal code mapping. The reference signals in the fifth scene group 1 are sequentially mapped to the first of the four OFDM symbols set as described above.

On the OFDM symbol and on the third OFDM symbol, occupy 3 subcarriers in the frequency domain; the reference signals in group 2 are sequentially mapped onto the second OFDM symbol and the fourth OFDM symbol of the four OFDM symbols, 3 subcarriers occupying different reference signals in group 1 in the frequency domain; reference signals in group 3 are sequentially mapped to the first OFDM symbol and the third OFDM symbol of the four OFDM symbols, occupying in the frequency domain 3 subcarriers identical to the reference signal in group 2; the reference signals in group 4 are sequentially mapped onto the second OFDM symbol and the fourth OFDM symbol on the four OFDM symbols, occupying and group 1 in the frequency domain The reference signal has the same 3 subcarriers; wherein: the reference signal in group 1 occupies the first, sixth, and eleventh subcarriers in the physical resource block, and the reference signal in group 2 occupies the second in the physical resource block The seventh, the twelfth subcarrier; or the reference signal in the group 1 occupies the first, fifth, and ninth subcarriers in the physical resource block, and the reference signal in the group 2 occupies the physical resource block Second, Sixth, tenth subcarrier; or

The reference signal in group 1 occupies the first, fifth, and ninth subcarriers in the physical resource block, and the reference signal in group 2 occupies the third, seventh, and eleventh sub-parts in the physical resource block. Carrier; or,

The reference signal in group 1 occupies the first, sixth, and eleventh subcarriers in the physical resource block, and the reference signal in group 2 occupies the second, seventh, and twelfth in the physical resource block. Subcarriers.

The reference signal data mapped on the carrier of the same frequency domain position in different time domain symbols in the same group is the same.

Fifth embodiment corresponding to the fifth scenario In this embodiment, the number of layers of the reference signal is 8, and the reference signal #0, the reference signal #1, and the reference signal #7 are respectively transmitted. The reference signals in group 1 are reference signals #0 and #4, the reference signals in group 2 are reference signals #1 and #5, and the reference signals in group 3 are reference signals #2 and #6, group 4 The reference signals in the order are reference signals #3 and #7 in sequence. Wherein, the reference signals #0, #1, #2, and #3 correspond to orthogonal codes of {1, 1}, and reference signals #4, #5, #6, and #7 correspond to orthogonal codes of {1, -1}. . Reference signal #0, located on the first, sixth, eleventh subcarriers of the second to last symbol of the first slot in the subframe, and the first of the second to last symbols of the second slot , the sixth, the eleventh subcarrier; the corresponding orthogonal code is {1, 1}. Reference signal #1, located on the second, seventh, and twelve subcarriers of the first symbol of the second time slot of the subframe, and the second, seventh, and twelve subcarriers of the first symbol of the second time slot The corresponding orthogonal code is {1, 1} ₀ reference signal #2, located on the second, seventh, twelfth subcarriers of the second to last symbol of the first slot in the subframe, and the second On the second, seventh, and twelfth subcarriers of the penultimate symbol of the slot; the corresponding orthogonal code is {1, 1}.

Reference signal #3, located on the first, sixth, eleventh subcarriers of the first symbol of the first time slot of the subframe, and the first and sixth symbols of the first symbol of the second time slot On the eleven subcarriers; the corresponding orthogonal code is {1, 1} ₀ reference signal #4, the first, sixth, eleventh subcarriers of the penultimate symbol of the first slot in the subframe And, on the first, sixth, and eleventh subcarriers of the second to last symbol of the second time slot; the corresponding orthogonal code is {1, -1}. Reference signal #5, located on the second, seventh, twelve subcarriers of the first symbol of the second time slot of the subframe, and the second, seventh, twelve subcarriers of the first symbol of the second time slot The corresponding orthogonal code is {1, -1} ₀ reference signal #6, located on the second, seventh, twelfth subcarriers of the penultimate symbol of the first slot in the subframe, and On the second, seventh, and twelfth subcarriers of the second to last symbols of the two slots; the corresponding orthogonal code is {1, -1}. Reference signal #7, located on the first, sixth, eleventh subcarriers of the first symbol of the first time slot of the subframe, and the first, sixth of the first symbol of the second time slot Eleven subcarriers; Corresponding orthogonal codes are {1, -1} _0. When the cyclic prefix is a regular cyclic prefix, the positions of these reference signals in the physical resource block are as shown in Fig. 8(a) and Fig. 8(b), where Fig. 8 (a) and FIG. 8(b) correspond to the time-frequency position and orthogonal code of the reference signal #0 to the reference signal #7, respectively, and the orthogonal code mapping method.

When all reference signals are grouped, all 8 layers of reference signals can be divided into 1 group, and the group includes 8 reference signals, wherein the orthogonal codes corresponding to the reference signals #0, #1, #2, and #3 are respectively {1, 1, 1, 1, 1, 1, 1, 1}, {1, -1, 1, -1, 1, -1, 1, -1}, {1, -1, -1, 1 , 1, -1, -1, 1} and {1, 1, -1, -1, 1, 1, -1, -1}, reference signals #4, #5, #6, and #7 correspond to positive The code is {1, 1, 1, 1, -1, -1, -1, -1}, {1, -1, 1, -1, -1, 1, -1, 1}, {1, -1, -1, 1, -1, 1, 1, -1} and {1, 1, -1, -1, -1, -1, 1, 1}. When the number of layers is h, only the corresponding reference signal #0, reference signal #1, reference signal #h-l, other reference signals are not sent. The reference signal is carried on a resource block of the corresponding physical shared channel. When all 8 layers of reference signals are divided into 1 group, it is the sixth scene as described below. The sixth scenario sequentially maps the reference signals in the group to the four OFDM symbols set by the foregoing, and occupies 6 subcarriers in the frequency domain, where the 6 subcarriers are the first, second, sixth, seventh, and eleventh. And the twelfth subcarrier, or the first, second, fifth, sixth, ninth and tenth subcarriers. The reference signal data mapped on the carrier of the same frequency domain location in the physical resource block in the different time domain symbols in the group is the same, and the first frequency domain location in the physical resource block is mapped on the carrier of the second frequency domain location. The reference signal data is the same, and the third frequency domain position in the physical resource block is the same as the reference signal data mapped on the carrier of the fourth frequency domain position, and the fifth frequency domain position and the sixth in the physical resource block are The reference signal data mapped on the carrier of the frequency domain location is the same. Corresponding to the sixth embodiment of the sixth scenario, in this embodiment, the number of layers of the reference signal is 8, respectively, transmitting the reference signal #0, the reference signal

#1, reference signal #7, where the orthogonal code corresponding to reference signal #0 is {1, 1, 1, 1, 1, 1, 1, 1}, and the orthogonal code corresponding to reference signal #1 is {1, -1, 1, -1, 1, -1, 1, -1}, Reference letter The orthogonal code corresponding to #2 is {1, -1, -1, 1, 1, -1, -1, 1}, and the orthogonal code corresponding to reference signal #3 is {1, 1, -1, - 1, 1, 1, -1, -1}, the orthogonal code corresponding to reference signal #4 is {1, 1, 1, 1, -1, -1, -1, -1}, corresponding to reference signal #5 The orthogonal code is {1, -1, 1, -1, -1, 1, -1, 1}, and the orthogonal code corresponding to reference signal #6 is {1, -1, -1, 1, -1 , 1, 1, -1}, and the orthogonal code corresponding to the reference signal #7 is {1, 1, -1, -1, -1, -1, 1, 1}. The reference signals #0, #1, #2, #3, #4, #5, #6, and #7 are located on the same time-frequency resource, that is, the second-to-last symbol of the first slot in the subframe. First, second, sixth, seventh, eleventh and twelfth, the first, second, sixth, seventh, eleventh and eleventh of the first symbol of the first time slot Twelve, the first, second, sixth, seventh, eleventh and twelfth of the penultimate symbol of the second time slot, and the first to the second of the second time slot The first, second, sixth, seventh, eleventh and twelfth symbols of the symbol. When the cyclic prefix is a normal cyclic prefix, when the position of these reference signals in a physical resource block in FIG. 9) to 9 (h), in which FIG. 9) to 9 (h) corresponding to T in Τ ₈ The location in the physical resource block. The reference signal transmitting method proposed by the invention ensures the transmission performance of the reference signal while ensuring the minimum reference signal overhead, and can be compatible with the existing LTE system, thereby realizing high-order ΜΙΜΟ transmission and improving The performance of the system. The above is only the embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalents, improvements, etc. made within the spirit and scope of the invention are intended to be included within the scope of the appended claims.

Industrial Applicability The method for transmitting a layer-based reference signal provided by the present invention ensures the transmission performance while ensuring the minimum reference signal overhead, and is compatible with the existing LTE system, thereby realizing The high-order ΜΙΜΟ transmission supports the use of the corresponding technology and improves the overall performance of the system.

Claims

Claim

A method for transmitting a reference signal, the reference signal being used for demodulation in an advanced long-term evolution system, the method comprising: dividing a reference signal corresponding to each layer into one or more groups, so that each group includes The reference signals are different from each other, the resources occupied by the reference signals in the same group are the same, and the reference signals in different groups occupy different physical time-frequency resources; and the reference signals in the same group are carried by code division multiplexing. On the same resource.

2. The method according to claim 1, further comprising: when the number of layers of the reference signal is h, sequentially transmitting the first h reference signals at a time-frequency domain location where the user-specific physical shared channel is located.

3. The method of claim 1 wherein:

The layer has 8 layers, and the reference signals corresponding to the layers are sequentially reference signal #0 of layer 1, reference signal #1 of layer 2, reference signal #2 of layer 3, reference signal #3 of layer 4, layer Reference signal #4 of 5, reference signal #5 of layer 6, reference signal #6 of layer 7, and reference signal #7 of layer 8;

The method further includes: setting four orthogonal frequency division multiplexing (OFDM) symbols, and mapping an eight-layer reference signal onto the four OFDM symbols;

The four OFDM symbols are respectively: a first OFDM symbol and a second last OFDM symbol of a first slot in a subframe, and a first OFDM symbol and a second to last OFDM of the second slot Or a symbol of the first OFDM symbol and the penultimate OFDM symbol of the first slot in the subframe, and a second to last OFDM symbol and a fourth OFDM symbol of the second slot; or

When the cyclic prefix in the subframe is a regular cyclic prefix, the four OFDM symbols are: a fourth OFDM symbol and a sixth OFDM symbol of the first slot in the subframe, and a fourth OFDM symbol OFDM symbol and sixth OFDM symbol; or, the fourth OFDM symbol and the seventh OFDM symbol of the first slot in the subframe and the third OFDM symbol and the sixth OFDM symbol of the second slot .

4. The method of claim 3, wherein: In the grouping step, the reference signals corresponding to the layers are divided into four groups, group 1, group 2, group 3, and group 4, each group comprising two reference signals, wherein

The group 1 includes the reference signal #0 and the reference signal #4 in turn, the group 2 includes the reference signal #1 and the reference signal #5 in sequence, the group 3 sequentially includes the reference signal #2 and the reference signal #6, and the group 4 sequentially includes the reference signal # 3 and reference signal #7; or,

The group 1 includes the reference signal #0 and the reference signal #7 in sequence, and the group 2 includes the reference signal #1 and the reference signal #6 in sequence, the group 3 sequentially includes the reference signal #2 and the reference signal #5, and the group 4 sequentially includes the reference signal # 3 and reference signal #4; or,

The group 1 includes the reference signal #0 and the reference signal #6 in turn, and the group 2 includes the reference signal #1 and the reference signal #7 in sequence, the group 3 sequentially includes the reference signal #2 and the reference signal #4, and the group 4 sequentially includes the reference signal # 3 and reference signal #5.

5. The method of claim 4, wherein:

The orthogonal code used in the step of carrying the reference signals on the same resource by means of code division multiplexing in the same group is: the orthogonal code used by the first reference signal of each of the four groups is { 1 , 1 }, the orthogonal code of the second reference signal of each group is {1, -1 }.

6. The method of claim 5, wherein the mapping comprises:

And sequentially mapping the reference signals in the group 1 to the first OFDM symbol and the third OFDM symbol of the four OFDM symbols, occupying 3 subcarriers in the frequency domain;

Mapping the reference signals in the group 2 to the second OFDM symbol and the fourth OFDM symbol of the four OFDM symbols, and occupying the same three sub-carriers in the frequency domain as the reference signals in the group 1 Carrier wave

Mapping the reference signals in the group 3 to the first OFDM symbol and the third OFDM symbol of the four OFDM symbols, occupying three sub-bands different from the reference signal in the group 1 in the frequency domain Carrier wave;

Mapping the reference signals in the group 4 to the second of the four OFDM symbols in sequence

On the OFDM symbol and the fourth OFDM symbol, the same three subcarriers as the reference signal in Group 3 are occupied in the frequency domain.

7. The method of claim 6 wherein: The three subcarriers occupied by the reference signal in the group 1 are: the first, sixth, and eleventh subcarriers in the physical resource block, and the three subcarriers occupied by the reference signal in the group 3 are: The second, seventh, and twelfth subcarriers in the physical resource block; or

The three subcarriers occupied by the reference signal in the group 1 are: the first, fifth, and ninth subcarriers in the physical resource block, and the three subcarriers occupied by the reference signal in the group 3 are: The second, sixth, and tenth subcarriers in the physical resource block; or

The three subcarriers occupied by the reference signal in the group 1 are: the first, fifth, and ninth subcarriers in the physical resource block, and the three subcarriers occupied by the reference signal in the group 3 are: The third, seventh, and eleventh subcarriers in the physical resource block.

8. The method of claim 5, wherein the mapping comprises:

Mapping the reference signals in the group 2 to the first OFDM symbol and the third OFDM symbol of the four OFDM symbols, occupying three sub-bands different from the reference signal in the group 1 in the frequency domain Carrier wave

And sequentially mapping the reference signals in the group 3 to the second OFDM symbol and the fourth OFDM symbol of the four OFDM symbols, occupying the same three subcarriers in the frequency domain as the reference signal in the group 1; as well as

The reference signals in the group 4 are sequentially mapped onto the second OFDM symbol and the fourth OFDM symbol of the four OFDM symbols, occupying the same three subcarriers as the reference signal in the group 2 in the frequency domain.

9. The method of claim 8 wherein:

The three subcarriers occupied by the reference signal in the group 1 are: the first, sixth, and eleventh subcarriers in the physical resource block, and the three subcarriers occupied by the reference signal in the group 2 are : the second, seventh, and twelfth subcarriers in the physical resource block; or

The three subcarriers occupied by the reference signal in the group 1 are: the first, fifth, and ninth subcarriers in the physical resource block, and the three subcarriers occupied by the reference signal in the group 2 are: The second, sixth, and tenth subcarriers in the physical resource block; or The three subcarriers occupied by the reference signal in the group 1 are: the first, fifth, and ninth subcarriers in the physical resource block, and the three subcarriers occupied by the reference signal in the group 2 are: The third, seventh, and eleventh subcarriers in the physical resource block.

10. The method of claim 5, wherein the mapping comprises:

Mapping the reference signals in the group 1 to the first of the four OFDM symbols in sequence

And occupying 3 subcarriers in the frequency domain on the OFDM symbol and the third OFDM symbol;

Mapping the reference signals in the group 2 to the second OFDM symbol and the fourth OFDM symbol of the four OFDM symbols, occupying three sub-bands different from the reference signal in the group 1 in the frequency domain Carrier wave

Mapping the reference signals in the group 3 to the first of the four OFDM symbols in sequence

And occupying, on the OFDM symbol and the third OFDM symbol, the same three subcarriers in the frequency domain as the reference signal in the group 2;

The reference signals in the group 4 are sequentially mapped to the second OFDM symbol and the fourth OFDM symbol of the four OFDM symbols, occupying the same three subcarriers as the reference signal in the group 1 in the frequency domain.

11. The method according to claim 10, wherein: the three subcarriers occupied by the reference signal in the group 1 are: first, sixth and eleventh subcarriers in the physical resource block, and the group The three subcarriers occupied by the reference signal in 2 are: the second, seventh, and twelfth subcarriers in the physical resource block; or the three subcarriers occupied by the reference signal in the group 1 are: the physical The first, fifth, and ninth subcarriers in the resource block, and the three subcarriers occupied by the reference signal in the group 2 are: second, sixth, and tenth subcarriers in the physical resource block; or The three subcarriers occupied by the reference signal in the group 1 are: the first, fifth, and ninth subcarriers in the physical resource block, and the three subcarriers occupied by the reference signal in the group 2 are: The third, seventh, and eleventh subcarriers in the physical resource block; or, the reference signal in the group 1 occupies the first, sixth, and eleventh subcarriers in the physical resource block And the reference signal in the group 2 occupies the Second, seventh, and twelfth subcarrier resource block processing.

The method according to claim 3, wherein: in the grouping step, the reference signals corresponding to the layers are divided into two groups, group 1 and group 2, each group comprising four reference signals, wherein Group 1 includes reference signal #0, reference signal #1, reference signal #4, and reference signal #5, respectively, and group 2 sequentially includes reference signal #2, reference signal #3, reference signal #6, and reference signal #7; Group 1 includes reference signal #0, reference signal #1, reference signal #6, and reference signal #7, respectively, and group 2 includes reference signal #2, reference signal #3, reference signal #4, and reference signal #5 in sequence; Alternatively, the group 1 sequentially includes the reference signal #0, the reference signal #1, the reference signal #4, and the reference signal #6, and the group 2 sequentially includes the reference signal #2, the reference signal #3, the reference signal #5, and the reference signal #7. Or, group 1 includes reference signal #0, reference signal #1, reference signal #5, and reference signal #7, respectively, and group 2 includes reference signal #2, reference signal #3, reference signal #4, and reference signal # in sequence. 6; or, group 1 contains parameters in turn Signal #0, reference signal #1, reference signal #4, and reference signal #7, and group 2 sequentially include reference signal #2, reference signal #3, reference signal #5, and reference signal #6; or, group 1 includes Reference signal #0, reference signal #1, reference signal #5 and reference signal #6, and group 2 sequentially include reference signal #2, reference signal #3, reference signal #4, and reference signal #7; or, group 1 in turn The reference signal #0, the reference signal #2, the reference signal #4, and the reference signal #6 are included, and the group 2 sequentially includes the reference signal #1, the reference signal #3, the reference signal #5, and the reference signal #7.

13. The method according to claim 12, wherein: the orthogonal code used in the step of carrying the reference signals in the same group by means of code division multiplexing on the same resource is: each of the two groups The first reference signal of the group adopts an orthogonal code of {I, 1, 1, 1}, and the orthogonal code of the second reference signal of each group is {1, -1, 1, -1}, The third reference signal of each group adopts an orthogonal code of {1, 1, -1, -1}, and the fourth reference signal of each group adopts an orthogonal code of {1, -1, -1, 1); or, the first reference signal of each of the two groups adopts an orthogonal code of {1, 1, 1, 1}, and the orthogonal code of the second reference signal of each group is { 1, -1, 1, -1}, the third reference letter for each group The orthogonal codes used are {1, -1, -1, 1 }, and the orthogonal codes used in the fourth reference signal of each group are {1, 1 , -1 , -1}.

14. The method according to claim 12, wherein the mapping comprises: sequentially mapping reference signals in the group 1 to the four OFDM symbols, occupying 3 subcarriers in a frequency domain; The reference signals in the group 2 are sequentially mapped onto the four OFDM symbols, occupying 3 subcarriers different from the reference signals in the group 1 in the frequency domain.

15. The method according to claim 14, wherein: the three subcarriers occupied by the reference signal in the group 1 are: first, sixth and eleventh subcarriers in the physical resource block, and the group The three subcarriers occupied by the reference signal in 2 are: the second, seventh, and twelfth subcarriers in the physical resource block; or the three subcarriers occupied by the reference signal in the group 1 are: in the physical resource block The first, fifth, and ninth subcarriers, and the reference signal in the group 2 occupy the second, sixth, and tenth subcarriers in the physical resource block; or, the reference signal in the group 1 occupies the physical The first, fifth, and ninth subcarriers in the resource block, and the reference signals in the group 2 occupy the third, seventh, and eleventh subcarriers in the physical resource block.

16. The method of claim 13, wherein the mapping comprises: sequentially mapping reference signals in the group 1 to a first one of the four OFDM symbols and a third OFDM Symbolically, occupying 6 subcarriers in the frequency domain; and sequentially mapping the reference signals in the group 2 to the second OFDM symbol and the fourth OFDM symbol of the four OFDM symbols, in the frequency domain The same 6 subcarriers as the reference signal in the group 1 are occupied.

17. The method according to claim 16, wherein: the six subcarriers are: first, second, sixth, seventh, eleventh and twelfth subcarriers in a physical resource block, or first , second, fifth, sixth, ninth and tenth subcarriers.

18. The method according to claim 3, wherein: in the grouping step, the reference signals corresponding to the layers are divided into one group, and the group includes eight reference signals;

The orthogonal codes used in the steps in which the reference signals in the group are carried on the same resource by means of code division multiplexing are: The orthogonal code used for the test signal #0 is {1, 1, 1, 1, 1 , 1, 1, 1};

The orthogonal code used in test signal #1 is {1, -1, 1, -1 1, -1, 1, -1}

The orthogonal code used in test signal #2 is {1, -1, -1, 1 1, -1, -1, 1}

The orthogonal code used in test signal #3 is {1, 1, -1, -1 1, 1, -1, -1}

The orthogonal code of the test signal #4釆 is {1 , 1, 1, 1, -1, ■ ■ 1, -1, -1}

The orthogonal code of the test signal #5釆 is {1, -1, 1, -1 -1, 1, -1, 1}

The orthogonal code used in test signal #6 is {1, -1, -1, 1 -1, 1, 1, -1} and the orthogonal code used in test signal #7 is {1, 1, -1, - 1 -1, -1, 1, 1}

The method of claim 18, wherein the mapping comprises: sequentially mapping reference signals in the group to the four OFDM symbols, occupying 6 subcarriers in a frequency domain;

The six subcarriers are: first, second, sixth, seventh, eleventh and twelfth subcarriers, or first, second, fifth, sixth, ninth and tenth subcarriers.

20. The method of claim 7, 9, 11, 15, 17, or 19, wherein: the reference signal data mapped on the carrier of the same frequency domain location in different time domain symbols in the same group is the same.

The method according to claim 1, wherein the layer has 8 layers, and the reference signals corresponding to the layers are sequentially reference signals #k of layer k; k are 0, 1, 2, 3, 4 respectively , 5, 6 and 7; wherein the sequence of the reference signal #k is generated according to the following formula: r(m) = -j=(l-2-c(2m)) + j^=(l-2-c(2m + Y)),m = 0,l,...,Ll where:

L is the sequence length required for the reference signal;

The pseudo-random sequence is generated according to the following formula:

c(z') = (x,(i + N _c ) + x ₂ (i + N _C )) mod 2

x, ( + 31) = ( , ( + 3 ) + x, ( ) ) mod 2

x ₂ (i + 31) = ( ₂ ( + 3) + x ₂ (i + 2) + x ₂ (, ' + 1) + x ₂ (/')) mod 2 where:

N _c =1600 ;

x _l (0) = \,x _l (n) = 0,n = l,2,...,30;

According to the pseudo-random sequence initial value c _imt = ∑ (") · 2 is generated;

Cinit is a positive integer greater than or equal to zero.

22. The method of claim 21, further comprising:

The sequence r(/w) of the reference signal is mapped to the antenna logical port p, the OFDM symbol /, subcarrier A by ag) = a ', _/) xr (w);

α( , _7·) is an orthogonal code factor, and

= 0JLj = 0, l, 2 or 3, a(i ) = l;

= 1 and = 0 or J = 2, a(i, y) = 1;

= 1 JL = 1 or 7 = 3 H† , a(i,j) = -\;

i = 23. j = Qor 7 = 13†, a(i,j) = \\

i = 23- j = 2or y = 30†, a(i,j)^-\]

z = 3 JL = 0 or 7 = 3 EI† , a(i, y) = 1; and i = 3JLj = lorj = 2H, α()·, ) = _1.