CN114125867A - Method and device for continuous signal coverage of 5G target area - Google Patents

Abstract

The present invention relates to the field of mobile technology, in particular to a method and device for continuous signal coverage of a 5G target area. Firstly, the channel parameters are estimated according to the eigenvalues of the target area, then the path loss value is calculated, and then the millimeter-wave bandwidth in the time domain and angular domain is calculated according to the space-time-space propagation model, and finally the LSAA antenna array is reasonably selected using the above calculation results. The LSAA antenna array arranged in the present invention can achieve precise and comprehensive coverage of the target area of the millimeter-wave mobile communication network, thereby providing users with a high-speed intelligent mobile communication network in hotspot areas, and meeting the needs of a large number of users for simultaneous online use. In addition, the method and device of the present invention can realize signal stability in the process of frequent area switching, and improve user satisfaction.

Description

Method and device for continuous signal coverage of 5G target area

technical field

The present invention relates to the field of mobile technology, in particular to a method and device for continuous signal coverage of a 5G target area.

Background technique

The explosive development of industrial applications such as mobile Internet, Internet of Things, and mobile live broadcasting has put forward higher requirements for mobile signal coverage. With the development of 5G mobile network, it will bring the possibility of "Internet of Everything". In outdoor environments, macro base stations and micro cells are usually used to achieve 5G mobile communication signal coverage. In indoor environments, indoor distribution systems are used as supplements and extensions to macro base stations and micro cells to improve the coverage of 5G mobile network target areas. Effect.

However, due to the high frequency, large path loss and poor penetration of the 5G system, the effective coverage area of outdoor base stations is reduced. In the indoor environment, the mobile communication signal coverage is weak, the signal in the target area cannot be continuously covered, and the terminal cannot be used normally, forming a blind area and a shadow area for mobile communication.

In order to solve the coverage problem of the target area, for example, a multi-channel indoor distribution system is proposed in Chinese patent application CN111313939. The near-end unit frequency shifts the frequencies of the signals output by the multi-channel source channels to different frequencies through frequency shifting technology. After the signal is combined, the cable of the existing single-channel indoor distribution system is used for transmission. The remote unit filters and frequency shifts the received combined signal, and restores it to the signal corresponding to the source channel. Under the premise of the cable and passive period of the single-channel indoor distribution system, the problem of indoor MIMO signal coverage can be solved. Although this solution can solve the coverage problem of the 5G signal target area within a certain period of time, in complex outdoor environments, such as frequent cell handovers, or the trend of users seeking more stable and higher-speed services, existing The technical solution is difficult to solve the above technical problems.

SUMMARY OF THE INVENTION

Purpose of the invention: The technical problem to be solved by the present invention is to provide a method and device for continuous signal coverage of a 5G target area in view of the deficiencies of the prior art.

In order to solve the above technical problems, the present invention discloses a method for continuous signal coverage of a 5G target area, comprising the following steps:

Step (1) extract the characteristic value of the target area, and perform channel parameter estimation on the actual link according to the characteristic value;

Step (2) use the path loss model to budget the actual link, and calculate the path loss value L _p of the target area;

Step (3) calculates the millimeter-wave bandwidth in the time domain and the angular domain of the target area according to the spatiotemporal space propagation model;

Step (4) According to the millimeter-wave bandwidth in the time domain and the angular domain, the number and the location of the base station LSAA are calculated.

In the present invention, the path loss model is used to budget the actual link, and the path loss value L _p of the target area is calculated, and the calculation formula is: P _r =P _t +G _t -L _p +G _r +G _s , where P _t is the transmit power in the RF output port, G _t is the transmit antenna gain, Gr is the receive antenna gain, G _s is the system gain with power amplifier, and P _{r is} the received signal power.

其中，t₀和t₁分别为接收功率P_omni(t)第一次和最后一次超过噪底NF的时间。In the present invention, the calculation formula of the received signal power P _r is:

Among them, t ₀ and t ₁ are the time when the received power P _omni (t) exceeds the noise floor NF for the first time and the last time, respectively.

In the present invention, the noise floor NF (Noise Floor) is calculated by the variance of each channel impulse response CIR (Channel Impulse Response) in the last 100 ns, which is a zero mean random measurement noise that obeys a Gaussian distribution.

In the present invention, the detection level is determined based on a signal-to-noise ratio SNR threshold relative to NF. The signal-to-noise ratio SNR (SIGNAL-NOISE RATIO) threshold of the noise floor NF ranges from -4dB to 10dB, preferably 4.5dB.

其中，In the present invention, the path loss model includes an indoor propagation model and an outdoor propagation model. The path loss formula is

in,

表示对数正态阴影衰落，即具有标准偏差的零均值高斯随机变量。L _FS (f,d ₀ )=20log ₁₀ d ₀ +20log ₁₀ f+32.44 represents the free path loss (FSPL) of the carrier frequency at the reference distance d ₀ (usually 1 km), and n represents the path fitted by the MMSE algorithm loss index,

Represents log-normal shadow fading, a zero-mean Gaussian random variable with standard deviation.

Under the indoor propagation model, the value range of n is usually 1.7-7, and the value range of σ is 1.5-4.

Under the outdoor propagation model, the value range of n is usually 2-4.

In the present invention, the outdoor propagation model includes human, plant or automobile obstruction situations. When there is a human, plant or car obstruction, it can be calculated based on the DKED (Double Edge Diffraction) model.

In the present invention, the millimeter wave frequency band is 25GHz-86GHz, preferably 28GHz-38GHz.

The invention also discloses a signal continuous coverage device for a 5G target area, comprising:

The downlink includes a millimeter-wave receiver, an IF downconverter, a baseband signal receiver, and an FPGA module connected in sequence.

The uplink consists of an FPGA module, a baseband signal transmitter, an IF upconverter, and a mmWave transmitter connected in sequence.

In the present invention, both the millimeter-wave receiver and the millimeter-wave transmitter are implemented with LSAA array antennas.

Further, the BS and UE use 128 and 4 LSAA array antenna elements, respectively.

The above technical scheme has the following beneficial effects:

The invention firstly estimates the channel parameters according to the characteristic value of the target area, then calculates the path loss value, then calculates the millimeter wave bandwidth in the time domain and the angular domain according to the space-time space propagation model, and finally uses the above calculation results to reasonably select the layout of LSAA The antenna array, through the LSAA antenna array arranged in the present invention, can achieve accurate and comprehensive coverage of the target area of the millimeter wave mobile communication network, thereby providing users with a high-speed intelligent mobile communication network in hotspot areas, and satisfying the simultaneous online use of a large number of users. In addition, the method and device of the present invention can achieve signal stability in the process of frequent area switching, and improve user satisfaction.

Description of drawings

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the above-mentioned and/or other aspects of the present invention will become clearer.

FIG. 1 is a system frame diagram of Embodiment 2 of the present invention.

Detailed ways

Example 1

This embodiment discloses a method for continuous signal coverage of a 5G target area, including the following steps:

1) Extract the eigenvalues of the target area, and estimate the channel parameters of the actual link according to the eigenvalues. The feature values of the target area include the geographical location of indoor and outdoor spaces, environmental parameters such as buildings, plants, etc. contained in the area, or information with high traffic such as shopping malls, large stadiums, and railway stations in the area. eigenvalues are collected. Through the collection of the above-mentioned eigenvalues, the channel parameters of the uplink and downlink can be estimated, and the minimum mean square error algorithm, ie, the MMSE algorithm, can be used for estimation.

其中，t₀和t₁分别为接收功率P_omni(t)第一次和最后一次超过噪底(NF)的时间。所述噪底(NF)是通过每个channel impulse response(CIR)最后100ns的方差计算而得，为服从高斯分布的零均值随机测量噪声。本实施例中，所述NF是基于信噪比(SNR)阈值来确定的，通过SNR阈值来确定NF，能够为接收信号功率计算过程中的积分区间进行精准确定，从而能够精准得到接收信号功率值。SNR阈值与载波频率、带宽及环境具有密切关系，通常是通过大量毫米波信道信道数据中的经验值。所述信道检测水平是基于相对于NF的信噪比SNR阈值来确定的。所述NF的信噪比SNR阈值范围为-4dB～10dB，优选4.5dB。当SNR选4.5dB时，采用MMSE算法进行信道检测误比特率是最低的，则MMSE算法检测水平在合适的SNR阈值范围内能够达到较优水平。MMSE算法为最小均方误差算法，令接收信号和发射信号的线性组合之间均方误差的期望值达到最小,公式为：δ＝arg min E{||A_MMSER-X||²}，δ表示期望，R表示接收信号矢量，X表示发射信号矢量，H表示系统信道矩阵。根据最优化理论得到最优检测矩阵A_MMSE＝(H^HH+σ²I)^-1H^H，σ²表示加性复高斯噪声的方差，满足E{nn^H}＝σ²I，再通过该检测矩阵计算出发射信号估计矢量

2) Use the path loss model to budget for the actual link, and calculate the path loss value L _p of the target area, and then use the path loss model to budget the actual link to calculate the path loss value L _p of the target area, which calculates The formula is: P _r =P _t +G _t -L _p +G _r +G _s , where P _t is the transmit power in the RF output port, G _t is the transmit antenna gain, _Gr is the receive antenna gain, and G _s is System gain with power amplifier, P _r is the received signal power. The calculation formula of the received signal power P _r is:

Among them, t ₀ and t ₁ are the time when the received power P _omni (t) exceeds the noise floor (NF) for the first time and the last time, respectively. The noise floor (NF) is calculated from the variance of the last 100 ns of each channel impulse response (CIR), which is a Gaussian distribution of zero mean random measurement noise. In this embodiment, the NF is determined based on a signal-to-noise ratio (SNR) threshold. The SNR threshold is used to determine the NF, which can accurately determine the integration interval in the received signal power calculation process, so that the received signal power can be accurately obtained. value. The SNR threshold is closely related to the carrier frequency, bandwidth and environment, and is usually an empirical value obtained from a large number of millimeter-wave channel channel data. The channel detection level is determined based on a signal-to-noise ratio SNR threshold relative to NF. The signal-to-noise ratio SNR threshold of the NF ranges from -4dB to 10dB, preferably 4.5dB. When the SNR is selected as 4.5dB, the bit error rate of channel detection using the MMSE algorithm is the lowest, and the detection level of the MMSE algorithm can reach a better level within the appropriate SNR threshold range. The MMSE algorithm is the minimum mean square error algorithm, which minimizes the expected value of the mean square error between the linear combination of the received signal and the transmitted signal. The formula is: δ=arg min E{||A _MMSE RX|| ² }, δ represents the expectation , R represents the received signal vector, X represents the transmitted signal vector, and H represents the system channel matrix. According to the optimization theory, the optimal detection matrix A _MMSE =(H ^H H+σ ² I) ^-1 H ^H is obtained, and σ ² represents the variance of the additive complex Gaussian noise, which satisfies E{nn ^H }=σ ² I, and then passes The detection matrix calculates the transmitted signal estimation vector

The path loss model includes an indoor propagation model and an outdoor propagation model. The outdoor propagation model includes human, plant or vehicle obstruction situations.

其中，L_FS(f,d₀)＝20log₁₀d₀+20log₁₀f+32.44表示基准距离d₀(通常为1公里)的载波频率f的自由路径损耗(FSPL)，n表示采用MMSE算法拟合的路径损耗指数，

表示对数正态阴影衰落，即具有标准偏差的零均值高斯随机变量。The free path loss _LCI (d) of the carrier frequency of the transmission distance d is calculated as:

Among them, L _FS (f,d ₀ )=20log ₁₀ d ₀ +20log ₁₀ f+32.44 represents the free path loss (FSPL) of the carrier frequency f at the reference distance d ₀ (usually 1 km), and n represents the MMSE algorithm combined path loss index,

Represents log-normal shadow fading, a zero-mean Gaussian random variable with standard deviation.

Under the indoor propagation model, the value range of n is usually 1.7-7, and the value range of σ is 1.5-4.

Under the outdoor propagation model, the value range of n is usually 2-4. When there is a human, plant or car obstruction, the calculation can be performed based on the DKED (Double Edge Diffraction) model.

3) Calculate the millimeter-wave bandwidth in the time domain and angular domain of the target area according to the spatiotemporal space propagation model,

4) According to the millimeter-wave bandwidth in the time domain and the angular domain, the number and location of the base station (BS) LSAA (multi-wave speed high-gain array antenna) are calculated. The millimeter wave frequency band is 25GHz-86GHz, preferably 28GHz-38GHz.

Referring to FIG. 1 , this embodiment also provides a signal continuous coverage device for a 5G target area, including:

The downlink includes a millimeter wave receiver, an IF downconverter, a baseband signal receiver, and an FPGA module connected in sequence,

The uplink includes an FPGA module, a baseband signal transmitter, an IF upconverter, and a millimeter wave transmitter that are connected in sequence.

In this embodiment, both the millimeter-wave receiver and the millimeter-wave transmitter are implemented using LSAA array antennas. The BS and UE use 128 and 4 LSAA array antenna elements, respectively. The LSAA array antenna can improve the reliable speed of light, and there is no need to detect the reliability of the communication link through other peripheral components. Therefore, when the transceiver moves or there is no LoS path, it can avoid the communication terminal, which will improve the spectral efficiency and anti-interference ability. .

The invention firstly estimates the channel parameters according to the characteristic value of the target area, then calculates the path loss value, then calculates the millimeter wave bandwidth in the time domain and the angular domain according to the space-time space propagation model, and finally uses the above calculation results to reasonably select the layout of LSAA The antenna array, through the LSAA antenna array arranged in the present invention, can achieve accurate and comprehensive coverage of the target area of the millimeter wave mobile communication network, thereby providing users with a high-speed intelligent mobile communication network in hotspot areas, and satisfying the simultaneous online use of a large number of users. In addition, the method and device of the present invention can achieve signal stability in the process of frequent area switching, and improve user satisfaction.

The present invention provides a method and device for continuous signal coverage of a 5G target area. There are many specific methods and approaches for implementing the technical solution. The above are only the preferred embodiments of the present invention. For personnel, without departing from the principle of the present invention, several improvements and modifications can also be made, and these improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be implemented by existing technologies.

Claims (10)

1. A signal continuous coverage method of a 5G target area is characterized by comprising the following steps:

extracting a characteristic value of a target area, and estimating a channel parameter of an actual link according to the characteristic value;

step (2) budgeting the actual link by using a path loss model, and calculating a path loss value L of the target area_p；

Step (3) calculating millimeter wave bandwidths in a time domain and an angular domain of the target area according to the space-time space propagation model;

and (4) calculating the number and the position of the LSAA of the base station according to the millimeter wave bandwidth in the time domain and the angular domain.

2. The method according to claim 1, wherein the actual link is budgeted by using a path loss model, and the path loss value L of the target area is calculated_pThe calculation formula is as follows: p_r＝P_t+G_t-L_p+G_r+G_sIn which P is_tFor the transmission power in the radio frequency output port, G_tFor transmitting antenna gain, G_rFor receiving antenna gain, G_sFor system gain with power amplifier, P_rIs the received signal power.

3. Method for signal continuous coverage of a 5G target area according to claim 2, wherein said received signal power P is_rThe calculation formula of (2) is as follows:

wherein, t₀And t₁Respectively, received power P_omni(t) the first and last times the noise floor NF is exceeded.

4. The method of claim 3, wherein the noise floor NF is calculated by variance of each channel impulse response CIR in the last 100ns, and is zero mean random measurement noise (SMR) subject to Gaussian distribution.

5. The method as claimed in claim 4, wherein the SNR threshold of the noise floor NF is in the range of-4 dB to 10 dB.

6. The method of claim 1, wherein the path loss model comprises an indoor propagation model and an outdoor propagation model, and the free path loss L of the carrier frequency of the transmission distance d is L_CI(d) The calculation formula is as follows:

wherein L is_FS(f,d₀)＝20log₁₀d₀+20log₁₀f +32.44 denotes the reference distance d₀Free path loss of carrier frequency fN denotes the path loss exponent fitted with the MMSE algorithm,

representing a lognormal shadowing fading, i.e., a zero-mean gaussian random variable with standard deviation.

7. The method of claim 6, wherein n is in a range of 1.7-7 and σ is in a range of 1.5-4 in an indoor propagation model, and n is in a range of 2-4 in an outdoor propagation model.

8. The method for signal continuous coverage of the 5G target area according to claim 1, wherein the millimeter wave frequency band is 25GHz-86GHz, preferably 28GHz-38 GHz.

9. A device for continuous coverage of signals in a 5G target area, comprising:

the down link comprises a millimeter wave receiver, an IF down converter, a baseband signal receiver and an FPGA module which are connected in sequence;

the uplink comprises an FPGA module, a baseband signal transmitter, an IF up-converter and a millimeter wave transmitter which are connected in sequence.

10. The apparatus of claim 9, wherein the millimeter wave receiver and the millimeter wave transmitter are implemented by LSAA array antenna.

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