CN103746946B

CN103746946B - Method for estimating Ior/Ec in multiple input multiple output communication (MIMO) system and terminal device

Info

Publication number: CN103746946B
Application number: CN201310739728.1A
Authority: CN
Inventors: 彭念; 余硕军; 邱少华; 孙凤宇
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2013-12-27
Filing date: 2013-12-27
Publication date: 2017-02-15
Anticipated expiration: 2033-12-27
Also published as: CN103746946A

Abstract

The invention discloses a method for estimating Ior/Ec in multiple input multiple output communication (MIMO) system and terminal device. The invention relates to the technical field of communication, if an extra information interaction between a cell and a terminal device is not increased, a more accurate estimation Ior/Ec can be obtain. The method comprises the following steps: for a first pilot signal and a second pilot signal to be despread and descrambled, respectively obtaining a channel response and a symbol level noise of at least two antennas; respectively obtaining a first covariance of noise item of the first pilot signal, a second covariance of noise item of the second pilot signal and a cross covariance between the noise items of the first pilot signal and the second pilot signal; according to the channel response of at least two antennaes, the noise covariance, the first covariance, the second covariance and the cross covariance of the symbol level noise of at least two antennaes, calculating the ratio of energy and pilot frequency energy of signal of at least two antennas. The terminal device is mainly used for equalization in the MIMO system.

Description

Method for estimating Ior/Ec in MIMO system and terminal equipment

Technical Field

The invention relates to the technical field of communication, in particular to a method for estimating the ratio Ior/Ec of signal energy to pilot energy in an MIMO system and terminal equipment.

Background

In an LTE (Long Term Evolution ) system, a MIMO (Multiple input Multiple Output) technology may be used to implement communication between a base station and a terminal, where the MIMO system is mainly characterized in that: based on the characteristic that a plurality of antennas are respectively arranged on a cell and terminal equipment, the MIMO system can realize data transmission between a base station and the terminal through a plurality of channels formed by the plurality of antennas, and has high frequency spectrum utilization rate.

When the base station communicates with the terminal, in order to compensate the system characteristics and reduce the intersymbol interference, the terminal estimates an equalization coefficient according to the Ior/Ec (total transmission power/pilot power) of each antenna of the base station, and performs equalization according to the equalization coefficient.

Currently, when estimating an equalization coefficient, a terminal uses a preset Ior/Ec.

However, in the MIMO system, the base station is provided with two or more antennas, each antenna usually transmits a pilot, but the pilot energy on each transmitting antenna is not necessarily the same; and other signals except the pilot frequency, such as various signaling channels, are usually sent only on the main antenna, so that the signals sent by the antennas are different; moreover, when each antenna transmits the same signal, the signal energy is generally different, so that the Ior/Ec of each antenna on the base station is different, the accuracy of estimating the equalization coefficient by adopting one preset Ior/Ec is lower, and the equalization performance of the terminal is poorer.

Taking PSP (Primary and Secondary Pilot pattern) in MIMO system as an example, in this pattern, the Primary antenna sends Primary Pilot, PDSCH and other common channels, the Secondary antenna only sends Secondary Pilot and PDSCH channels, and different Pilot powers are usually configured on the Primary antenna and the Secondary antenna, and when the terminal performs channel estimation according to the pilots on the Primary/Secondary transmitting antennas, the result contains respective Pilot energy sqrt (ec). Therefore, the channel estimation result needs to be finally converted to a traffic channel during equalization to construct equalizer coefficients. If the terminal cannot accurately acquire the Ior/Ec of the main antenna and the auxiliary antenna, the terminal is difficult to estimate the equalizer coefficient.

Similarly, in the case of multiple cells, the pilot power of the main cell and the pilot power of its neighboring cells are also different, and it is difficult for the terminal to estimate the equalizer coefficients.

In order to solve the problem, the base station can send each antenna Ior/Ec to the terminal at intervals, and the terminal estimates the equalization coefficient according to the received Ior/Ec. In estimating Ior/Ec in this way, the inventors found that at least the following problems existed: in order to reflect the current Ior/Ec in time, the base station needs to frequently send additional data to the terminal, which greatly increases signal cost and wastes wireless resources.

Disclosure of Invention

Embodiments of the present invention provide a method for estimating Ior/Ec in an MIMO system and a terminal device, which can obtain a more accurate ratio of estimated signal energy to pilot energy without increasing additional information interaction between a cell and the terminal device.

In order to achieve the above purpose, the embodiment of the invention adopts the following technical scheme:

in a first aspect, the present invention provides a method for estimating a signal energy-to-pilot energy ratio, which is used for a wireless terminal, where the wireless terminal is used for receiving a first pilot signal and a second pilot signal respectively transmitted by a transmitting device through at least two antennas, and the method includes:

descrambling and despreading the first pilot signal and the second pilot signal to respectively acquire channel responses and symbol-level noise of the at least two antennas;

respectively solving a first covariance of a noise item of the first pilot signal and a second covariance of a noise item of the second pilot signal, and a cross covariance between the noise item of the first pilot signal and the noise item of the second pilot signal;

and calculating the energy-to-pilot energy ratio of the signals of the at least two antennas according to the channel responses of the at least two antennas, the noise variance of the symbol-level noise of the at least two antennas, the first covariance, the second covariance and the cross covariance.

With reference to the first aspect, in a first possible implementation manner of the first aspect, the obtaining the symbol-level noise of the at least two antennas separately includes, for a kth cell, where the total signal y is sent by N antennas, N is a non-zero natural number, and K e (1, N) is a non-zero natural number: obtaining symbol-level noise of the at least two antennas through a first equation set, wherein the first equation set comprises:

wherein l is a channel number, n is an antenna number, k is a cell number,symbol-level noise variance of the l channel corresponding to the k cell for antenna m α_nIs the ratio of the signal energy of antenna n to the pilot energy, | h_mn,k,l|²Is an antenna on the k cell_nThe square of the modulus of the channel response of the channel l with the antenna m;m is the antenna number, x is the digital signal serial number, SF is the coefficient,the total energy of the signal with sequence number 1 to the signal with sequence number SF on the antenna m.

With reference to the first possibility of the first aspect, in a second possible implementation manner of the first aspect, the obtaining a cross-covariance between the noise term of the first pilot signal and the noise term of the second pilot signal includes:

for signal noise z on any two antennas of the at least two_m,k,lPerforming conjugate correlation calculation to construct a conjugate equation containing signal cross-correlation, energy, noise variance, noise cross-correlation, signal energy-to-pilot energy ratio and channel response vector on each antenna, wherein m is the antenna number, l is the channel number, k is the cell number, z is the cell number_m,k,lNoise of the l channel corresponding to the k cell for the antenna m;

and obtaining the cross covariance between the noise term of the first pilot signal and the noise term of the second pilot signal according to the conjugate equation.

With reference to the second possible implementation manner of the first aspect, in a third possible implementation manner of the first aspect, the conjugate equation includes:

wherein SF is the coefficient, z_1,k,lThe signal noise of the l channel of the antenna 1 on the k cell; z is a radical of_2,k,lThe signal noise of the l channel of the antenna 2 in the k cell;is composed ofMean value of α₁Signal energy to pilot energy ratio for antenna 1, α₂Is the signal energy to pilot energy ratio for antenna 2,the cross covariance of signal noise items of a channel l corresponding to a kth cell and two antennas is obtained;is the cross-covariance, h, between the signal noise terms on the two antennas_11,k,lIs the channel response of the channel l between antenna 1 and antenna 1 on the kth cell, h_12,k,lIs the channel response of the channel i between antenna 2 and antenna 1 on the kth cell,is the channel response conjugate of channel i between antenna 1 and antenna 2 on the kth cell,is the channel response conjugate of antenna 2 and channel l between antenna 2 on the kth cell.

With reference to the third possible implementation manner of the first aspect, in a fourth possible implementation manner of the first aspect, the obtaining a cross-covariance between a noise term of the first pilot signal and a noise term of the second pilot signal according to the conjugate equation includes:

splitting the conjugate equation into:

real part equation:

imaginary part equation:

acquiring a construction matrix equation according to the split real part equation and the split imaginary part equation:

wherein,

the calculating the energy-to-pilot energy ratio of the signals of the at least two antennas according to the channel responses of the at least two antennas, the noise variance of the symbol-level noise of the at least two antennas, the first covariance, the second covariance, and the cross covariance, comprises: and calculating the energy-to-pilot energy ratio of the signals of the at least two antennas according to the constructed matrix equation system.

With reference to any one of the possible implementation manners of the first aspect, in a fifth possible implementation manner of the first aspect, when noise of pilot signals sent by the at least two antennas is obtained, the noise is treated as gaussian white noise, where the noise includes inter-path interference, inter-cell interference, and white noise.

In a second aspect, the present invention provides a terminal device, including:

a receiving device, configured to receive a first pilot signal and a second pilot signal that are sent by a sending device through at least two antennas respectively;

a descrambling and despreading device, configured to descramble and despread the first pilot signal and the second pilot signal, and obtain channel responses and symbol-level noise of the at least two antennas respectively;

signal processing means for respectively finding a first covariance of a noise term of the first pilot signal and a second covariance of a noise term of the second pilot signal, and a cross covariance between the noise term of the first pilot signal and the noise term of the second pilot signal;

estimating means for calculating a ratio of energy to pilot energy of each of the signals of the at least two antennas based on the channel responses of the at least two antennas, the noise variance of each of the symbol-level noise of the at least two antennas, the first covariance, the second covariance, and the cross covariance.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the total signal y is transmitted by N antennas, where N is a non-zero natural number, and for a kth cell, K ∈ (1, N), the receiving apparatus is specifically configured to: obtaining symbol-level noise of the at least two antennas through a first equation set, wherein the first equation set comprises:

With reference to the first possibility of the second aspect, in a second possible implementation manner of the second aspect, the signal processing apparatus is specifically configured to:

for signal noise z on any two antennas of the at least two_m,k,lPerforming conjugate correlation calculation to construct a conjugate equation containing signal cross-correlation, energy, noise variance, noise cross-correlation, signal energy-to-pilot energy ratio and channel response vector on each antenna, wherein m is the antenna number, l is the channel number, k is the cell number, z is the cell number_m,k,lNoise of the l channel corresponding to the k cell for the antenna m; and obtaining the cross covariance between the noise term of the first pilot signal and the noise term of the second pilot signal according to the conjugate equation.

With reference to the second possible implementation manner of the second aspect, in a third possible implementation manner of the second aspect, the conjugate equation includes:

With reference to the third possible implementation manner of the second aspect, in a fourth possible implementation manner of the second aspect, the signal processing apparatus is specifically configured to:

splitting the conjugate equation into:

real part equation:

imaginary part equation:

and acquiring a construction matrix equation according to the split real part equation and imaginary part equation:

wherein,

the estimation device is specifically configured to: and calculating the energy-to-pilot energy ratio of the signals of the at least two antennas according to the constructed matrix equation system.

With reference to any one of the possible implementation manners of the second aspect, in a fifth possible implementation manner of the second aspect, the receiving device is further configured to, when obtaining noise of pilot signals sent by the at least two antennas, treat the noise as gaussian white noise, where the noise includes inter-path interference, inter-cell interference, and white noise.

The method for estimating Ior/Ec in the MIMO system and the terminal equipment provided by the embodiment of the invention adopt the following method to estimate the ratio of signal energy to pilot energy, firstly, receiving a total signal y sent by a base station through M terminal equipment antennas, and then estimating a channel response vector of each channel; descrambling and despreading the signal of each channel to obtain a pilot signal on each channel; obtaining signal noise on each channel according to the pilot signal on the channel; constructing an equation set containing at least M equations according to the variance of the noise, the channel response vector, the total signal y and the first functional relation of the ratio of the signal energy to the pilot frequency energy for each channel; and estimating the signal energy to pilot frequency energy ratio of each transmitting antenna according to an equation set, wherein in the process, the signal energy to pilot frequency energy ratio is estimated according to corresponding parameters of signals, so that more accurate signal energy to pilot frequency energy ratio can be obtained, additional information interaction between a cell and terminal equipment is not increased, and wireless resources are effectively saved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a flowchart of a method for estimating a signal energy to pilot energy ratio according to an embodiment of the present invention;

FIG. 2 is a flow chart of another method for estimating a signal energy to pilot energy ratio according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a MIMO system in the embodiment corresponding to fig. 1 and fig. 2;

fig. 4 is a flowchart of a scheduling method in a MIMO system according to an embodiment of the present invention;

FIG. 5 is a flow chart illustrating CQI calculation in the embodiment corresponding to FIG. 4;

fig. 6 is a schematic structural diagram of a terminal device according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a scheduling apparatus in a MIMO system according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The embodiment of the invention provides a method for estimating Ior/Ec in an MIMO system, which comprises the following steps as shown in figure 1:

101. and descrambling and despreading the first pilot signal and the second pilot signal to respectively acquire the channel responses and the symbol-level noise of the at least two antennas.

Such as: the cell is provided with N antennas, M channels are shared between the cell and the terminal equipment, and the terminal equipment estimates each channel to obtain a channel response vector. In this embodiment, the cell base station sends signals to the terminal device through the N antennas, and when the terminal device processes the signals, the terminal device may select signals sent by 2 antennas from the signals, and process the signals sent by the 2 selected antennas through the scheme of the present invention.

102. Respectively solving a first covariance of a noise item of the first pilot signal and a second covariance of a noise item of the second pilot signal, and a cross covariance between the noise item of the first pilot signal and the noise item of the second pilot signal;

the correlation calculation result includes an autocorrelation calculation result of the pilot signal transmitted by each antenna and a conjugate correlation calculation result between the pilot signals transmitted by two different antennas of the at least two antennas.

103. And calculating the energy-to-pilot energy ratio of the signals of the at least two antennas according to the channel responses of the at least two antennas, the noise variance of the symbol-level noise of the at least two antennas, the first covariance, the second covariance and the cross covariance.

The terminal equipment obtains the signal noise according to the pilot signal, and the method for the terminal equipment to specifically obtain the noise signal in the embodiment of the invention is realized by adopting a pilot reconstruction mode.

The terminal equipment can determine the variance of the noise in a pilot frequency reconstruction mode; the channel response vector can be estimated by the existing method; the total signal y can be calculated by the existing method; in this embodiment, only the signal energy to pilot energy ratio is unknown, and therefore, after the equation formed by the above variables is listed, the signal energy to pilot energy ratio can be obtained by solving the equation.

In the method for estimating Ior/Ec in the MIMO system provided by this embodiment, a ratio of signal energy to pilot energy is estimated by using a method that, first, receives a total signal y sent by a base station through M terminal device antennas, and then, estimates a channel response vector of each channel; descrambling and despreading the signal of each channel to obtain a pilot signal on each channel; obtaining signal noise on each channel according to the pilot signal on the channel; constructing an equation set containing at least M equations according to the variance of the noise, the channel response vector, the total signal y and the first functional relation of the ratio of the signal energy to the pilot frequency energy for each channel; and estimating the signal energy to pilot frequency energy ratio of each transmitting antenna according to an equation set, wherein in the process, the signal energy to pilot frequency energy ratio is estimated according to corresponding parameters of signals, so that more accurate signal energy to pilot frequency energy ratio can be obtained, additional information interaction between a cell and terminal equipment is not increased, and wireless resources are effectively saved.

As an improvement of the embodiment corresponding to fig. 1, an embodiment of the present invention provides another method for estimating Ior/Ec in a MIMO system, where a terminal device is provided with at least one antenna, and a terminal device with two antennas R1 and R2 is taken as an example in the MIMO system, and as shown in fig. 2 specifically, the method includes:

201. the terminal equipment receives a first pilot signal and a second pilot signal which are respectively sent by the sending equipment through at least two antennas.

In the embodiment of the present invention, each cell is not described, and a cell with a number k is taken as an example for description, and functions and operations of other cells may be similar.

As shown in fig. 3, the cell with number k is provided with two antennas T1 and T2, and the base station with number k and the terminal device perform data transmission via channel 11, channel 12, channel 21, and channel 22. Wherein, the terminal device can receive the total signal y transmitted by the cell through 2 terminal device antennas.

And calculates a total signal from a plurality of cells by formula (1),(1) in formula 1, y (x) is a signal with a sequence x received by the terminal device from the 1 st to the kth terminal device, x is a digital signal sequence, K is a cell number, h_k＝[h_k,1,…,h_k,L]^TIs the channel response vector for cell k,_lfor the purpose of channel numbering,is the transmitted signal vector of cell k, v (x) is an independent and identically distributed gaussian random variable,

202. and descrambling and despreading the first pilot signal and the second pilot signal to respectively acquire the channel responses of the at least two antennas.

The terminal equipment carries out channel estimation on each cell, and for the kth cell, the terminal equipment respectively estimates a channel 11, a channel 12, a channel 21 and a channel 22 to obtain a kth cell channel response vector h_kThe channel estimation method in the embodiment of the present invention is implemented by using the prior art, and is not described herein again.

203. And acquiring the symbol-level noise of the at least two antennas through a first equation set.

The first set of equations includes:

wherein l is a channel number, n is an antenna number, k is a cell number,α variance of symbol-level noise for the l channel corresponding to the k cell for antenna m_nIs the ratio of the signal energy of antenna n to the pilot energy, | h_mn,k,l|²Is an antenna on the k cell_nAnd the square of the modulus of the channel response of the channel/between the antennas m.m is the antenna number, x is the digital signal serial number, SF is the coefficient,the total energy of the signal with sequence number 1 to the signal with sequence number SF on the antenna m.

204. A first covariance of a noise term of the first pilot signal and a second covariance of a noise term of the second pilot signal are separately determined.

205, for signal noise z on any two antennas of the at least two_m,k,lAnd performing conjugate correlation calculation to construct a conjugate equation comprising signal cross correlation, energy, noise variance, noise cross correlation, signal energy-to-pilot energy ratio and channel response vectors on each antenna.

Wherein m is an antenna number, l is a channel number, k is a cell number, z_m,k,lIs the noise of the l channel corresponding to the k cell for antenna m.

And 206, obtaining the cross covariance between the noise term of the first pilot signal and the noise term of the second pilot signal according to the conjugate equation.

Wherein the conjugate equation comprises:

wherein SF is the coefficient, z_1,k,lIs the signal noise of the l-th channel of antenna 1 in the k-th cell. z is a radical of_2,k,lIs the signal noise of the l channel of antenna 2 in the k cell.Is composed ofMean value of α₁Signal energy to pilot energy ratio for antenna 1, α₂Is the signal energy to pilot energy ratio for antenna 2,is the cross covariance between the signal noise terms of the k cell and the channel l corresponding to the two antennas.Is the cross-covariance, h, between the signal noise terms on the two antennas_11,k,lIs the channel response of the channel l between antenna 1 and antenna 1 on the kth cell, h_12,k,lIs the channel response of the channel i between antenna 2 and antenna 1 on the kth cell,is the channel response conjugate of channel i between antenna 1 and antenna 2 on the kth cell,is the channel response conjugate of antenna 2 and channel l between antenna 2 on the kth cell.

Specifically, for this embodiment, the terminal device descrambles and despreads the received signal on each antenna, and descrambled and despread noise z_k,lIncluding inter-path interference, inter-cell interference and white noise, which can be approximately regarded as gaussian white noise, which is a known technique in the art, specificallyRefers to noise with a power spectral density that is uniformly distributed throughout the frequency domain. The random noise having the same energy at all frequencies is called white noise and is not described herein. The mean is zero and the variance isComprises the following steps:

in the formula (1) and the formula (2),in the formula, x is the digital signal serial number, SF is the coefficient,the total energy from the signal with the sequence number 1 to the signal with the sequence number SF on the terminal equipment antennas 1 and 2. l is the channel number, k is the cell number,the variance of the symbol-level noise for the l channel corresponding to the kth cell for terminal equipment antenna R1,variance of symbol-level noise for the l channel corresponding to the k cell for terminal equipment antenna R2 α₁For Signal energy to Pilot energy ratio of Transmit antenna T1, α₂Is the signal energy to pilot energy ratio, | h, of the transmit antenna T2_11,k,l|²Is the square of the modulus of the channel of channel l between the transmitting antenna T1 and the terminal equipment antenna R1 on the kth cell, | h_12,k,l|²Channel response for channel l between transmit antenna T2 and terminal device antenna R1 on the kth cellSquare of the modulus, | h_21,k,l|²Is the square of the modulus of the channel response of channel l between the transmit antenna T1 and the terminal equipment antenna R2 on the kth cell, | h_22,k,l|²Is the square of the modulus of the channel response of channel i between transmit antenna T2 and terminal equipment antenna R2 on the kth cell.

In the formulas (1) and (2), only α is included₁、α₂The other variables can be obtained by estimation, calculation and the like, and if the cross-correlation between the antennas is not considered, α can be solved by formula (1) and formula (2) at this time₁、α₂For a terminal device with L antennas, the signal energy to pilot energy ratio can be calculated separately on each antenna and combined by adopting the maximum ratio, and two receiving antennas with the maximum signal-to-noise ratio can be selected.

Wherein, obtaining the cross covariance between the noise term of the first pilot signal and the noise term of the second pilot signal according to the conjugate equation may include:

and splitting the conjugate equation into a real part equation and an imaginary part equation.

Real part equation:

imaginary part equation:

each matrix in equation (5) is as follows,

when two diameters are selected for calculation, equation (5b) can be written specifically as:

in the above formula, z_1,k,lAnd z_2,k,lIs the noise at the symbol level after descrambling and despreading. The terminal equipment can reconstruct the sending signal by the pilot frequency and subtract the reconstructed signal from the pilot frequency data after descrambling and despreading to obtain z_1,k,lAnd z_2,k,l。

207. And calculating the energy-to-pilot energy ratio of the signals of the at least two antennas according to the constructed matrix equation system.

Order to

Then there is

α can be obtained by the following equation (6)₁、α₂Solving α₁、α₂The process of (a) may use LMS and the like, which are well known to those skilled in the art and will not be described herein.

When the following equations (10), (11) and (12) hold, the maximum likelihood solution can be obtained.

Solving the maximum likelihood as:

wherein,H′_k,lonly the k cell and the l channel are included, if a plurality of channels exist, H 'is expanded'_kThe number of rows of (a) to (b),

other variables are analogized in turn。

Observing equation (18) can see that when α has only one row of variables, i.e., the cell has only one transmit antenna, it is equivalent to combining the maximum ratio.

When there are more than two transmit antennas in a cell, the receive can be similarly derived to obtain the signal energy to pilot energy ratio, Ior/Ec, on the multiple transmit antennas.

In the method for estimating Ior/Ec in the MIMO system provided by this embodiment, a ratio of signal energy to pilot energy is estimated by using a method that, first, receives a total signal y sent by a base station through M terminal device antennas, and then, estimates a channel response vector of each channel; descrambling and despreading the signal of each channel to obtain a pilot signal on each channel; obtaining signal noise on each channel according to the pilot signal on the channel; constructing an equation set containing at least M equations according to the variance of the noise, the channel response vector, the total signal y and the first functional relation of the ratio of the signal energy to the pilot frequency energy for each channel; and estimating the signal energy to pilot frequency energy ratio of each transmitting antenna according to an equation set, wherein in the process, the signal energy to pilot frequency energy ratio is estimated according to corresponding parameters of signals, so that more accurate signal energy to pilot frequency energy ratio can be obtained, additional information interaction between a cell and terminal equipment is not increased, and wireless resources are effectively saved. Moreover, not only the autocorrelation of the antennas but also the cross-correlation among the antennas are considered, so that the ratio of the calculated signal energy to the pilot energy is more accurate.

The MIMO system has a mixed network with MIMO and non-MIMO, the MIMO-UE is a terminal supporting multiple input and multiple output, the non-nIMO-UE is a terminal not supporting multiple input and multiple output, and a main pilot frequency, a signaling channel, a MIMO PDSCH and a non-nIMO PDSCH are transmitted on a main antenna on a cell; and transmitting an auxiliary pilot frequency and a MIMO PDSCH channel on an auxiliary antenna, wherein the transmission power of the auxiliary pilot frequency is variable and is less than or equal to the main pilot frequency power. The network informs the MIMOUE of the power offset between the primary and secondary pilots. This solution solves the hybrid networking problem well, but it can be seen that the transmission power on the virtual antennas is unbalanced, which affects the performance of the terminal device. And for non-nmoimo UEs, signals on the secondary antenna of the terminal device cause additional interference to them; for a MIMO UE, the non-nmo PDSCH signal transmitted on the primary antenna may cause its performance to degrade. In order to solve the technical problem, an embodiment of the present invention provides a scheduling method in a MIMO system, where as shown in fig. 4, the method includes:

401. and determining the first time and the second time according to the service proportion or the quantity proportion of the MIMO-UE and the non-nIMO-UE.

A user scheduling table may be stored in the cell, where the scheduling time allocation of MIMO-UE and non-nmimo-UE is recorded, and the following is allocated according to the specific situation:

in the first case, the number of MIMO-UE and non-nmo-UE in the MIMO system is substantially equal, and the information in the user scheduling table indicates that the scheduling time of MIMO-UE and non-nmo-UE is equal, for example, the scheduling time is set to 50ms, that is, the current 50ms schedules MIMO-UE, the next 50ms schedules non-nmo-UE, and so on;

in the second case, the number of MIMO-UEs in the MIMO system is significantly greater than the number of non-nmo-UEs, and the information in the user scheduling table indicates that the scheduling time of MIMO-UE and non-nmo-UE is not equal, for example, the scheduling time of MIMO-UE is set to 50ms, the scheduling time of non-nmo-UE is set to 10ms, that is, the current 50ms schedules MIMO-UE, the next 10ms schedules non-nmo-UE, and so forth;

in other cases, the MIMO-UE and non-nmimo-UE scheduling times are not equal, nor are they repeated regularly as in the second case, but rather are specified according to the frequency of use of MIMO-UE and non-nmimo-UE traffic for a specific time period, as in 9 a.m.: and when the use frequency of the 00MIMO-UE is high, the MIMO-UE scheduling time of the user scheduling table in the time period is long, and the like.

The time allocation can be preset, or can be allocated by RNC () according to the scheduling rate proportion, the throughput rate proportion or the number proportion of the activated UEs of the MIMO-UE and the non-NMO-UE in the cell. If the setting is preset, networking or other time presetting may be performed, in which case step 401 may be omitted.

402. Only MIMO-UEs are scheduled at a first time instant and no physical downlink shared channel PDSCH of non-nmo-UEs is transmitted on the primary antenna.

When the MIMO-UE is scheduled, the MIMO-UE calculates the signal-to-noise ratio according to the auxiliary pilot power and the main pilot power.

In this embodiment, since the power of the secondary pilot is variable, when calculating the CQI, the MIMO UE needs to convert the secondary pilot power to the primary pilot power to calculate the SNR, and obtain the CQI and report the CQI to the cell. The conversion process is to multiply the energy of the auxiliary pilot frequency by the ratio Ec of the energy of the main pilot frequency and the auxiliary pilot frequency₁/Ec₂. Meanwhile, if the PowerOffset value assigned by the upper layer is the sum of the power of the main pilot and the power of the auxiliary pilot, the converted SNR needs to be modified, and the CQI is obtained and reported by the modified SNR.

In particular, the method comprises the following steps of,

wherein Bias _ dB ═ 10 × log10 (Power)_SCPICH/Power_CPICH)。

For the sum of the translated pilot energies, the true PowerOffset factor by which the reported CQI needs to be multiplied is

Conversion to linear values

Further optionally, the method further comprises:

403. only non-nmo-UEs are scheduled at the second time instant and on the secondary antenna to transmit secondary pilot signals.

When scheduling non-nIMO-UE, MIMO-UE uses estimated Ior/Ec of last scheduled time to perform equalization calculation.

When scheduling a user of non-nIMO, no service is provided for MIMO UE at this time, and the MIMO UE needs to report a CQI value. However, at two different scheduling time instants, the transmission power of the NodeB is changed, and the Ior/Ec value corresponding to the primary and secondary pilots is also changed, i.e. when scheduling a non-nmimo user, the CQI reported by the MIMO UE does not truly reflect the channel quality when scheduling the MIMO user.

For MIMO-UE, the equalization coefficient is calculated by using the Ior/Ec of the last time of scheduling MIMO user during equalization. Then convolving the equalization coefficient with the channel estimate to obtain the channel estimate after equalization, and calculating the noise power estimate after equalization to obtain the noise power estimate, where a specific flow is shown in fig. 5 and includes:

in the first step, the MIMO-UE calculates an equalization coefficient by using the estimated Ior/Ec, the channel estimation parameter and the noise power estimation when being scheduled last time, and performs equalization filtering.

And secondly, convolving the equalization coefficient with the channel estimation to obtain the equalized channel estimation.

And thirdly, calculating the noise power estimation after the equalization according to the equalization coefficient and the noise power estimation.

And fourthly, calculating the CQI according to the channel estimation after the equalization and the noise power estimation after the equalization.

Further optionally, the method may further include:

404. the MIMO-UE and the non-nIMO-UE estimate Ior/Ec according to the method of the corresponding embodiment of the figures 1 and 2.

Note that, there is no sequence in the implementation of steps 402 and 403, and this embodiment only shows one execution condition, and the specific execution sequence is determined according to the actual situation.

The method comprises the steps that a cell adopts a time-sharing scheduling mode when terminal equipment is scheduled, so that MIMO-UE and non-nIMO-UE are not scheduled at the same time, only MIMO users are scheduled at the first time, and the PDSCH of the non-nIMO is not arranged on a main antenna at the moment, so that the power imbalance of the two virtual antennas is not serious; at the moment 2, only the non-nIMO user is scheduled, only the auxiliary pilot signal exists on the auxiliary antenna at the moment, and the auxiliary pilot signal can be removed through an interference elimination method, so that the system performance is effectively improved.

In order to implement the method for estimating Ior/Ec in the MIMO system described in the corresponding embodiments of fig. 1 and fig. 2, an embodiment of the present invention provides a terminal device, as shown in fig. 6, including: .

A receiving device 61, configured to receive a first pilot signal and a second pilot signal that are respectively sent by a sending device through at least two antennas;

a descrambling and despreading device 62, configured to descramble and despread the first pilot signal and the second pilot signal, and obtain channel responses and symbol-level noise of the at least two antennas respectively;

signal processing means 63 for respectively finding a first covariance of a noise term of the first pilot signal and a second covariance of a noise term of the second pilot signal, and a cross covariance between the noise term of the first pilot signal and the noise term of the second pilot signal;

estimating means 64 for calculating a ratio of energy to pilot energy of each of the signals of the at least two antennas based on the channel responses of the at least two antennas, the noise variance of each of the symbol-level noise of the at least two antennas, the first covariance, the second covariance, and the cross covariance.

The terminal device provided in this embodiment estimates the ratio of signal energy to pilot energy by using the following method, first, receiving a total signal y sent by a base station through M terminal device antennas, and then estimating a channel response vector of each channel; descrambling and despreading the signal of each channel to obtain a pilot signal on each channel; obtaining signal noise on each channel according to the pilot signal on the channel; constructing an equation set containing at least M equations according to the variance of the noise, the channel response vector, the total signal y and the first functional relation of the ratio of the signal energy to the pilot frequency energy for each channel; and estimating the signal energy to pilot frequency energy ratio of each transmitting antenna according to an equation set, wherein in the process, the signal energy to pilot frequency energy ratio is estimated according to corresponding parameters of signals, so that more accurate signal energy to pilot frequency energy ratio can be obtained, additional information interaction between a cell and terminal equipment is not increased, and wireless resources are effectively saved.

Specifically, in this embodiment, the receiving device 61 is specifically configured to: and acquiring the symbol-level noise of the at least two antennas through a first equation set. Wherein the total signal y is transmitted by N antennas, N is a non-zero natural number, and for the Kth cell, K belongs to (1, N).

The first set of equations includes:

Further, the signal processing device 63 is specifically configured to: for signal noise z on any two antennas of the at least two_m,k,lPerforming conjugate correlation calculation to construct a conjugate equation containing signal cross-correlation, energy, noise variance, noise cross-correlation, signal energy-to-pilot energy ratio and channel response vector on each antenna, wherein m is the antenna number, l is the channel number, k is the cell number, z is the cell number_m,k,lNoise of the l channel corresponding to the k cell for the antenna m; and obtaining the cross covariance between the noise term of the first pilot signal and the noise term of the second pilot signal according to the conjugate equation.

Wherein the conjugate equation comprises:

The signal processing device 63 is specifically configured to:

wherein the conjugate equation can be split into:

real part equation:

imaginary part equation:

wherein,

the estimation means 64 are in particular configured to: and calculating the energy-to-pilot energy ratio of the signals of the at least two antennas according to the constructed matrix equation system.

Optionally, the receiving device 61 is further configured to, when obtaining noise of the pilot signals sent by the at least two antennas, treat the noise as gaussian white noise, where the noise includes inter-path interference, inter-cell interference, and white noise.

In order to implement the scheduling method in the MIMO system described in the embodiment corresponding to fig. 4, an embodiment of the present invention provides a scheduling apparatus in the MIMO system, as shown in fig. 7, where the MIMO system includes two terminals, a MIMO-UE and a non-nmimo-UE, the MIMO-UE supports multiple-input multiple-output, the non-nmimo-UE does not support multiple-input multiple-output, and the MIMO-UE and the non-nmimo-UE are not scheduled at the same time, and the apparatus includes: a first scheduling unit 91, a second scheduling unit 92, and a time determination unit 93.

Wherein the first scheduling unit 91 is configured to schedule only the MIMO-UE at the first time, and not transmit the physical downlink shared channel of the non-MIMO-UE on the primary antenna.

Further optionally, the method further includes:

a second scheduling unit 92 for scheduling only non-mimo-UEs at a second time instant and transmitting secondary pilot signals on the secondary antenna.

Preferably, the first time and the second time are predetermined;

further optionally, the apparatus further comprises:

and a time determining unit 93, configured to determine the first time and the second time according to the traffic ratio or the quantity ratio of the MIMO-UE and the non-nmimo-UE.

Preferably, the first and second liquid crystal materials are,

the MIMO-UE and the non-MIMO-UE are provided with the terminal device of any of claims 16-22; or,

the MIMO-UE and the non-MIMO-UE are provided with the equalizer of claim 23.

Preferably, the first and second liquid crystal materials are,

when the first scheduling unit 91 schedules the MIMO-UE, the MIMO-UE calculates a signal-to-noise ratio according to the secondary pilot power and the primary pilot power.

Preferably, the first and second liquid crystal materials are,

when the second scheduling unit 92 schedules non-nMOM-UE, the MIMO-UE performs equalization calculation using the estimated Ior/Ec of the last scheduled time.

The scheduling apparatus in the MIMO system provided in this embodiment estimates a ratio of signal energy to pilot energy by using the following method, first, receiving a total signal y sent by a base station through M terminal device antennas, and then estimating a channel response vector of each channel; descrambling and despreading the signal of each channel to obtain a pilot signal on each channel; obtaining signal noise on each channel according to the pilot signal on the channel; constructing an equation set containing at least M equations according to the variance of the noise, the channel response vector, the total signal y and the first functional relation of the ratio of the signal energy to the pilot frequency energy for each channel; and estimating the signal energy to pilot frequency energy ratio of each transmitting antenna according to an equation set, wherein in the process, the signal energy to pilot frequency energy ratio is estimated according to corresponding parameters of signals, so that more accurate signal energy to pilot frequency energy ratio can be obtained, additional information interaction between a cell and terminal equipment is not increased, and wireless resources are effectively saved.

An embodiment of the present invention provides a base station, including: the scheduling apparatus is the scheduling apparatus described in the embodiment corresponding to fig. 7, the base station sends a signal to the terminal through the antenna, and the scheduling apparatus is configured to implement scheduling of the terminal by the base station.

The base station provided by this embodiment estimates the ratio of signal energy to pilot energy by the following method, first, receives the total signal y sent by the base station through M terminal device antennas, and then estimates the channel response vector of each channel; descrambling and despreading the signal of each channel to obtain a pilot signal on each channel; obtaining signal noise on each channel according to the pilot signal on the channel; constructing an equation set containing at least M equations according to the variance of the noise, the channel response vector, the total signal y and the first functional relation of the ratio of the signal energy to the pilot frequency energy for each channel; and estimating the signal energy to pilot frequency energy ratio of each transmitting antenna according to an equation set, wherein in the process, the signal energy to pilot frequency energy ratio is estimated according to corresponding parameters of signals, so that more accurate signal energy to pilot frequency energy ratio can be obtained, additional information interaction between a cell and terminal equipment is not increased, and wireless resources are effectively saved.

In the embodiments, the Ior/Ec of each antenna in the cell can be adjusted according to different services, and the terminal device can more accurately obtain the current Ior/Ec of the cell. And the terminal equipment performs equalization according to the obtained current Ior/Ec. Under the condition of not increasing the data transmitted by a transmitter, the embodiment of the invention can be applied to an Ior/Ec estimation method in an MIMO system.

Through the above description of the embodiments, those skilled in the art will clearly understand that the present invention may be implemented by software plus necessary general hardware, and certainly may also be implemented by hardware, but in many cases, the former is a better embodiment. Based on such understanding, the technical solutions of the present invention may be embodied in the form of software products, or solidified in a chip, the software products being stored in a readable storage medium, such as a floppy disk, a hard disk, or an optical disk of an estimator, and including instructions for enabling an estimator (which may be a personal estimator, a server, or a network device) to execute the methods according to the embodiments of the present invention.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method of estimating a signal energy to pilot energy ratio for a wireless terminal configured to receive first and second pilot signals transmitted by a transmitting device via at least two antennas, respectively, the method comprising:

2. The method of claim 1, wherein a total signal y is transmitted by N antennas, N is a non-zero natural number, and for a kth cell, K e (1, N), said separately obtaining symbol-level noise for the at least two antennas comprises: obtaining symbol-level noise of the at least two antennas through a first equation set, wherein the first equation set comprises:

\begin{matrix} z_{1, k, l}^{2} = \frac{1}{S F} (σ_{y 1}^{2} - α_{1} {| h_{11, k, l} |}^{2} - α_{2} {| h_{12, k, l} |}^{2} - ...... α_{n} {| h_{1 n, k, l} |}^{2}), \\ z_{2, k, l}^{2} = \frac{1}{S F} (σ_{y 2}^{2} - α_{1} {| h_{21, k, l} |}^{2} - α_{2} {| h_{22, k, l} |}^{2} - ...... α_{n} {| h_{2 n, k, l} |}^{2}), \\ ......, \\ z_{m, k, l}^{2} = \frac{1}{S F} (σ_{y m}^{2} - α_{1} {| h_{m 1, k, l} |}^{2} - α_{2} {| h_{m 2, k, l} |}^{2} - ...... α_{n} {| h_{m n, k, l} |}^{2}), \end{matrix}

wherein l is a channel number, n is an antenna number, k is a cell number,symbol-level noise variance of the l channel corresponding to the k cell for antenna m α_nIs the ratio of the signal energy of antenna n to the pilot energy, | h_mn,k,l|²Is the square of the modulus of the channel response of the channel l between antenna n and antenna m in the kth cell;m is the antenna number and x is the digital signalThe sequence number, SF, is a coefficient,the total energy of the signal with sequence number 1 to the signal with sequence number SF on the antenna m.

3. The method of claim 2, wherein the determining the cross-covariance between the noise term of the first pilot signal and the noise term of the second pilot signal comprises:

4. The method of claim 3, wherein the conjugate equation comprises:

wherein SF is the coefficient, z_1,k,lThe signal noise of the l channel of the antenna 1 on the k cell; z is a radical of_2,k,lThe signal noise of the l channel of the antenna 2 in the k cell;is composed ofMean value of α₁Signal energy to pilot energy ratio for antenna 1, α₂Being an antenna 2The ratio of the signal energy to the pilot energy,the cross covariance of signal noise items of a channel l corresponding to a kth cell and two antennas is obtained;is the cross-covariance, h, between the signal noise terms on the two antennas_11,k,lIs the channel response of the channel l between antenna 1 and antenna 1 on the kth cell, h_12,k,lIs the channel response of the channel i between antenna 2 and antenna 1 on the kth cell,is the channel response conjugate of channel i between antenna 1 and antenna 2 on the kth cell,is the channel response conjugate of antenna 2 and channel l between antenna 2 on the kth cell.

5. The method of claim 4, wherein obtaining the cross-covariance between the noise term of the first pilot signal and the noise term of the second pilot signal according to the conjugate equation comprises:

splitting the conjugate equation into:

real part equation:

imaginary part equation:

wherein,

6. The method according to any of claims 1-5, wherein the noise of the pilot signals transmitted by the at least two antennas is obtained and treated as Gaussian white noise, and the noise comprises inter-path interference, inter-cell interference, and white noise.

7. A terminal device, comprising:

8. The terminal device of claim 7, wherein the total signal y is transmitted by N antennas, N is a non-zero natural number, and for a kth cell, K ∈ (1, N), the receiving device is specifically configured to: obtaining symbol-level noise of the at least two antennas through a first equation set, wherein the first equation set comprises:

\begin{matrix} z_{1, k, l}^{2} = \frac{1}{S F} (σ_{y 1}^{2} - α_{1} {| h_{11, k, l} |}^{2} - α_{2} {| h_{12, k, l} |}^{2} - ...... α_{n} {| h_{1 n, k, l} |}^{2}), \\ z_{2, k, l}^{2} = \frac{1}{S F} (σ_{y 2}^{2} - α_{1} {| h_{21, k, l} |}^{2} - α_{2} {| h_{22, k, l} |}^{2} - ...... α_{n} {| h_{2 n, k, l} |}^{2}), \\ ......, \\ z_{m, k, l}^{2} = \frac{1}{S F} (σ_{y m}^{2} - α_{1} {| h_{m 1, k, l} |}^{2} - α_{2} {| h_{m 2, k, l} |}^{2} - ...... α_{n} {| h_{m n, k, l} |}^{2}), \end{matrix}

9. The terminal device of claim 8, wherein the signal processing apparatus is specifically configured to:

10. The terminal device of claim 9, wherein the conjugate equation comprises:

11. The terminal device of claim 10, wherein the signal processing apparatus is specifically configured to:

splitting the conjugate equation into:

real part equation:

imaginary part equation:

wherein,

12. The terminal device according to any of claims 7-11, wherein the receiving device is further configured to, when acquiring noise of the pilot signals transmitted by the at least two antennas, treat the noise as gaussian white noise, where the noise includes inter-path interference, inter-cell interference, and white noise.