CN109714777B - Method for acquiring time-space isolation and frequency isolation of coexistence of TD-LTE system and DTMB system - Google Patents
Method for acquiring time-space isolation and frequency isolation of coexistence of TD-LTE system and DTMB system Download PDFInfo
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Abstract
The invention belongs to the technical field of wireless communication, and discloses a method for acquiring space isolation and frequency isolation when a TD-LTE system and a DTMB system coexist; calculating interference power received by the disturbed radio receiver; calculating the bottom noise of the receiver; calculating the transmission path loss when the distance between the interference transmitter and the interfered receiver is d according to the dry-to-noise ratio protection criterion; calculating space isolation and frequency isolation requirements required by the coexistence of the two systems according to a dry-to-noise ratio protection criterion; and calculating the space isolation and frequency isolation requirements required by the coexistence of the two systems according to the spectrum templates of the two systems. The invention can carry out feasibility analysis on the same spectrum resource shared by different systems through the spectrum templates of the two systems, reduce the mutual interference between the different systems according to the requirements of space isolation and frequency isolation and improve the utilization rate of the spectrum resource.
Description
Technical Field
The invention belongs to the technical field of wireless communication, and particularly relates to a method for acquiring space isolation and frequency isolation when a TD-LTE system and a DTMB system coexist.
Background
Currently, the current state of the art commonly used in the industry is such that: according to the statistical analysis result of the idle spectrum resources, the spectrum use conditions between countries and regions are greatly different. And under the condition that the spectrum occupancy rate is less than a certain specific value, idle spectrum resources which can deploy the TD-LTE system still exist in a time domain, a frequency domain and a space domain. Coexistence analysis is an effective means for performing spectrum resource management and frequency planning, and is also one of key technologies in the process of improving the utilization rate of spectrum resources by using the CR technology. The secondary user acquires the opportunity access of the idle frequency spectrum resource through a sensing method, in order to ensure that harmful interference is not generated to the primary user, the secondary user needs to perform coexistence analysis with the frequency band to be accessed and services existing in adjacent frequency bands, calculates radio frequency parameters suitable for system coexistence, and then opportunistically accesses the idle frequency band under the condition of ensuring certain frequency interval, distance interval, power control and the like, so that the situation of frequency shortage is relieved under the condition of not generating interference to the primary user, and the utilization rate of the frequency spectrum resource is improved. The method for acquiring space isolation and frequency isolation based on the spectrum template is a method for analyzing coexistence of different systems, and is used for evaluating feasibility of sharing the same section of spectrum resources by a plurality of systems. And (3) evaluating whether the cognitive user generates harmful interference on the main user or not, wherein the evaluation depends on the size of the signal-to-interference ratio. In order to ensure that the communication quality is still good at the edge of the radio coverage area, that is, in consideration of near-far effect, the signal-to-interference ratio requirement can still be met under the condition of receiver sensitivity, so that the interference-to-noise ratio is often used to replace the signal-to-interference ratio for the coexistence analysis between radio services, and the communication system can still work normally under the worst condition. At present, most coexistence analysis methods adopt an Adjacent Channel Leakage Ratio (ACLR) and an Adjacent Channel Selection (ACS) to perform deterministic analysis and monte carlo simulation analysis, and the coexistence situation between systems is measured by the loss degree of link throughput. The method needs to know the average power of the occupied frequency band and the center frequency of the adjacent frequency band passing through the filter respectively, and whether the average power can coexist or not is related to the receiving performance of the receiver.
In summary, the problems of the prior art are: the Adjacent Channel Leakage Ratio (ACLR) and Adjacent Channel Selection (ACS) methods require knowledge of the average power of the filters passing through the center frequencies of the occupied band and the adjacent band, respectively, and whether coexistence can occur is related to the reception performance of the receiver.
The difficulty and significance for solving the technical problems are as follows:
the invention adopts the frequency spectrum templates and the radio frequency parameters of different systems to carry out coexistence analysis, and can directly provide space isolation and frequency isolation which need to be met when different systems coexist; and the interference-to-noise ratio is adopted to replace the signal-to-interference ratio to carry out the deterministic coexistence analysis among the radio services, thereby ensuring that the communication system can still work normally under the worst condition.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a flow chart of a method for acquiring space isolation and frequency isolation when a TD-LTE system and a DTMB system coexist.
The invention is realized in such a way that a TD-LTE system and DTMB system coexisting time-space isolation and frequency isolation obtaining method comprises the following steps:
the method comprises the following steps that firstly, interference power received by a disturbed radio receiver is calculated;
secondly, calculating the background noise of the receiver;
thirdly, calculating the transmission path loss when the distance between the interference transmitter and the interfered receiver is d according to a dry-to-noise ratio protection criterion;
fourthly, calculating space isolation and frequency isolation requirements required by the coexistence of the two systems according to the dry-to-noise ratio protection criterion;
and fifthly, calculating the space isolation and frequency isolation requirements required by the coexistence of the two systems according to the frequency spectrum templates of the two systems.
Further, according to the radio wave propagation theory, the interference power received by the disturbed radio receiver is calculated as:
I＝P t +G t (θ 1 )-L t +G r (θ 2 )-L r -L p (d)-FDR(Δf)；
wherein:
P t the unit is dBm, which is the transmitting power of an interference source;
G t (θ 1 ) The antenna gain for the interferer in the interference direction is in dBi;
G r (θ 2 ) The antenna gain in dBi for a disturbed receiver in the direction of the disturbance;
θ 1 、θ 2 the axial off-axis angles of the interference direction deviating from the axial direction of the interference antenna or the interfered antenna are respectively, and the unit is an angle;
L p (d) the unit is dB of transmission path loss when the distance between an interference transmitter and a disturbed receiver is d;
L t the unit is dB for the feeder loss of the transmitting end;
L r the unit is dB for the feeder loss of a receiving end;
FDR (Δ f) is a frequency suppression factor, in dB, defined as:
wherein:
p (f) is the power spectral density of the interference signal in W/kHz;
h (f) is the frequency response of the if filter of the victim receiver;
Δ f is the frequency separation (kHz) of the victim receiver from the disturber transmitter. When delta f is 0, the signal is co-channel interference;
interference signal power
H(f) 2 The FDR (delta f) is more than or equal to 0 by reflecting the spectrum template characteristic of the receiver.
Further, the calculating the background noise of the receiver specifically includes:
receiver ground noise is mainly generated by the thermal motion of charged particles with the power:
N＝-174+10lgB+NF；
b is the medium frequency bandwidth in Hz and NF is the noise figure in dB.
Further, calculating the transmission path loss at a distance d between the interfering transmitter and the interfered receiver according to the dry-to-noise ratio protection criterion comprises
According to the dry-to-noise ratio protection criterion, INR is less than or equal to beta, beta is the INR protection requirement, and the unit is dB, then
The propagation model of the LTE system adopts an Omura HATA model to calculate the path loss, and the formula is as follows:
wherein L is p (d) The unit is a medium value of electric wave propagation loss of the quasi-smooth terrain, and is dB; f is the working frequency and the unit is MHz; h is 1 The effective height of the base station antenna is m; h is 2 Is the effective height of the mobile station antenna, and the unit is m; d is the distance between the mobile station and the base station, and the unit is km; alpha (h) 2 ) In dB for the mobile station antenna height factor.
Expression for the large city α (h 2):
α(h 2 )＝3.2[lg(11.75h 2 )] 2 -4.97(f＞400MHz)；
expression for suburban area α (h 2):
further, the space isolation and frequency isolation requirements required by the coexistence of the two systems are calculated according to a dry-to-noise ratio protection criterion, and the protection distance is as follows:
the guard distance d has a direct relationship with the frequency separation Δ f of the victim receiver from the disturber.
Another object of the present invention is to provide a wireless communication system applying the method for acquiring space isolation and frequency isolation when the TD-LTE system coexists with the DTMB system.
In summary, the advantages and positive effects of the invention are: the invention adopts the frequency spectrum templates and the radio frequency parameters of different systems to carry out coexistence analysis, can directly give out space isolation and frequency isolation which need to be met when different systems coexist, and does not need to know the average power of the occupied frequency band and the central frequency of the adjacent frequency band passing through the filter; and the interference-to-noise ratio is adopted to replace the signal-to-interference ratio for carrying out deterministic coexistence analysis among the radio services, the change condition of the link throughput is not required to be calculated, and the normal work of the communication system under the worst condition can be ensured.
The method can calculate the requirements of space isolation and frequency isolation when a TD-LTE system and a DTMB system coexist in a suburban scene; according to the space isolation and the frequency isolation calculated by the method, the coexistence problem of the two systems can be effectively solved; under the condition of meeting the requirements of space isolation and frequency isolation, the utilization rate of frequency spectrum resources can be effectively improved.
Drawings
Fig. 1 is a flowchart of a method for acquiring space isolation and frequency isolation when a TD-LTE system and a DTMB system coexist according to an embodiment of the present invention.
Fig. 2 is a schematic diagram of a spectrum template of a TD-LTE base station according to an embodiment of the present invention.
Fig. 3 is a schematic diagram of a spectrum template of a digital broadcasting system according to an embodiment of the present invention.
Fig. 4 is a schematic diagram of a relationship between a frequency suppression factor (d) and a frequency interval Δ f of interference DTMB in the TD-LTE system according to an embodiment of the present invention.
Fig. 5 is a schematic diagram of a relationship between a spatial isolation distance (d) and a frequency interval Δ f of interference DTMB in the TD-LTE system according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The invention provides a method for acquiring the spatial isolation and the frequency isolation of the coexistence of a TD-LTE system and a DTMB system, which is based on a spectrum template and directly obtains the relation between the required protection distance and the frequency interval when the different systems coexist through deterministic analysis.
The following detailed description of the principles of the invention is provided in connection with the accompanying drawings.
As shown in fig. 1, the method for acquiring space isolation and frequency isolation when the TD-LTE system and the DTMB system coexist according to the embodiment of the present invention includes the following steps:
s101: calculating interference power received by the disturbed radio receiver; calculating the bottom noise of the receiver; calculating the transmission path loss when the distance between the interference transmitter and the interfered receiver is d according to the dry-to-noise ratio protection criterion;
s102: calculating the space isolation and frequency isolation requirements required by the coexistence of the two systems according to the dry-to-noise ratio protection criterion;
s103: and calculating the space isolation and frequency isolation requirements required by the coexistence of the two systems according to the spectrum templates of the two systems.
The application of the principles of the present invention will now be described in further detail with reference to the accompanying drawings.
The method for acquiring space isolation and frequency isolation when the TD-LTE system and the DTMB system coexist specifically comprises the following steps:
step one, calculating interference power received by an interfered radio receiver;
according to the radio wave propagation theory, the interference power received by the disturbed radio receiver is:
I＝P t +G t (θ 1 )-L t +G r (θ 2 )-L r -L p (d)-FDR(Δf) (1)
wherein:
P t the unit is dBm, which is the transmitting power of an interference source;
G t (θ 1) antenna gain of the interferer in the interference direction, in dBi;
gr (θ 2) is the antenna gain of the victim receiver in the interference direction, in dBi;
θ 1 、θ 2 the axial off-axis angles of the interference direction deviating from the axial direction of the interference antenna or the interfered antenna are respectively, and the unit is an angle;
L p (d) the unit is dB of transmission path loss when the distance between an interference transmitter and a disturbed receiver is d;
L t is the transmission end feeder loss in dB;
L r the unit is dB for the feeder loss of a receiving end;
FDR (Δ f) is the frequency suppression factor in dB, defined as:
wherein:
p (f) is the power spectral density (W/kHz) of the interfering signal;
h (f) is the frequency response of the if filter of the victim receiver;
Δ f is the frequency separation (kHz) of the victim receiver from the disturber transmitter. When Δ f is 0, it is co-channel interference.
As can be seen from equation (2), the interference signal power
H(f) 2 The FDR (delta f) is more than or equal to 0 and reflects the spectrum template characteristic of the receiver.
And step two, calculating the background noise of the receiver.
Receiver noise is mainly generated by the thermal motion of charged particles, with the power:
N＝-174+10lgB+NF(dBm) (3)
where B is the intermediate frequency bandwidth (Hz) and NF is the noise figure (dB).
Step three, according to the dry-to-noise ratio protection criterion, INR is less than or equal to beta, beta is the INR protection requirement, dB is as follows:
obviously, the difference in θ can be obtained according to the formula (4) 1 、θ 2 The relation d- Δ f under the condition, which describes the FD rule of coexistence between radio services, also reflects the multi-dimensionality of space, frequency and orientation of the spectrum resources.
The FD rule is related to radio propagation models, and different propagation models may affect the FD rule calculation result. The propagation model of the LTE system adopts an Omura HATA model to calculate the path loss, and the formula is as follows:
wherein L is p (d) The medium value (dB) of the electric wave propagation loss of the quasi-smooth terrain; f is the operating frequency (MHz); h is 1 Is the base station antenna effective height (m); h is 2 Is the mobile station antenna effective height (m); d is the distance (km) between the mobile station and the base station; alpha (h) 2 ) Is the mobile station antenna height factor (dB).
For large cities, α (h) 2 ) Is represented by formula (6):
α(h 2 )＝3.2[lg(11.75h 2 )] 2 -4.97(f＞400MHz) (6)
for suburbs, α (h) 2 ) Is represented by the formula (7):
and step four, calculating the space isolation and frequency isolation requirements required by the coexistence of the two systems according to the dry-to-noise ratio protection criterion. And (3) bringing the formula (5) in the step four into the formula (4), wherein the obtained protection distance is as follows:
as can be seen from equation (8), the guard distance d has a direct relationship with the frequency separation Δ f between the victim receiver and the disturber transmitter when the two coexistence systems are determined.
And step five, calculating the space isolation and frequency isolation requirements required by the coexistence of the two systems according to the frequency spectrum templates of the two systems.
According to typical 20MHz bandwidth TD-LTE parameters given by 3GPP, the main radio frequency parameters of TD-LTE are shown in Table 1. The spectrum template of the TD-LTE base station when the measurement bandwidth is 20MHz is shown in figure 2.
TABLE 1
| Base station | Mobile terminal | |
| Bandwidth (MHz) | 20 | 20 |
| Launch power (dBm) | 43 | 23 |
| Antenna gain (dBi) | 15 | 0 |
| Antenna height (m) | 25 | 1.5 |
| Feeder loss (dB) | 2 | 0 |
| Noise figure (dB) | 5 | 9 |
| INR requirements (dB) | -7 | 0 |
The chinese digital tv broadcasting system provides parameters of the chinese digital tv broadcasting system required for the coexistence research according to GB20600-2006 "frame structure, channel coding and modulation of digital tv terrestrial broadcasting transmission system" and GY/Y237-2008 "VHF/UHF band terrestrial digital tv broadcasting frequency planning criteria", as shown in table 2. The corresponding signal power was measured at a 4KHz bandwidth, where 0dB corresponds to the total output power, and the spectrum template is shown in fig. 3.
From fig. 3, an expression of a spectrum template of a broadcast television system can be obtained, as shown in equation (9):
in the invention, the interference condition of the TD-LTE system to the DTMB system when the two systems are deployed in a frequency band of 698-806 MHz in a suburban scene is considered, and the frequency isolation and distance isolation requirements which are required to be met when the two systems coexist are obtained. In the coexistence analysis research of the two systems in the suburban scene, the adopted propagation model is an HATA suburban model. Since a typical parameter given by the DTMB system is SNR, the SNR needs to be converted into INR.
As can be seen from table 2, the SNR required for the DTMB system to receive is 20dB, and when the SNR deviates by 1dB, the β requirement required for the DTMB system is:
according to the interference mechanism of the TD-LTE system to the DTMB system, the coexistence analysis result of the TD-LTE system base station to the DTMB system is obtained by using the formula (8) and is shown in table 3.
TABLE 2
| Launch power (dBm) | 60,70 |
| Transmitting antenna height (m) | 150 |
| Transmitting antenna gain (dBi) | 9 |
| Height of receiving antenna (m) | 10 |
| Receiving antenna gain (dBi) | 12 |
| Feed loss of receiving antenna (dB) | 5 |
| Signal-to-noise ratio (S/N) (dB) required for |
20 |
TABLE 3
According to the results of the coexistence analysis of the two systems obtained in table 3, the relationship between FDR and the frequency interval Δ f of the TD-LTE interfering DTMB system and the relationship between d and Δ f can be obtained, as shown in fig. 4 and fig. 5, respectively. As can be seen from table 3, when the frequency interval Δ f is 0MHz, that is, the two systems are in the same frequency state, the FDR is 4.17dB, and d should reach at least 35.2Km to ensure coexistence of the two systems; when the frequency interval is 14MHz ≦ Δ f < 24MHz, namely the two systems are in an adjacent frequency state, the FDR increases along with the increase of Δ f, and d decreases along with the increase of Δ f; when Δ f ≧ 24MHz, FDR and d do not change with increasing Δ f, becoming a constant.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (1)
1. A method for acquiring space isolation and frequency isolation when a TD-LTE system and a DTMB system coexist, the method comprising the steps of:
the method comprises the steps of firstly, calculating interference power received by an interfered radio receiver;
secondly, calculating the background noise of the receiver;
thirdly, calculating the transmission path loss when the distance between the interference transmitter and the interfered receiver is d according to a dry-to-noise ratio protection criterion;
fourthly, calculating space isolation and frequency isolation requirements required by the coexistence of the two systems according to the dry-to-noise ratio protection criterion;
fifthly, calculating the space isolation and frequency isolation requirements required by the coexistence of the two systems according to the frequency spectrum templates of the two systems;
according to the radio wave propagation theory, the interference power received by the disturbed radio receiver is calculated as:
I＝P t +G t (θ 1 )-L t +G r (θ 2 )-L r -L p (d)-FDR(Δf)；
wherein:
P t the unit is dBm, which is the transmitting power of an interference source;
G t (θ 1 ) Antenna gain in dBi for the interference source in the interference direction;
G r (θ 2 ) The antenna gain in dBi for a disturbed receiver in the direction of the disturbance;
θ 1 、θ 2 the axial off-axis angles of the interference direction deviating from the axial direction of the interference antenna or the interfered antenna are respectively, and the unit is an angle;
L p (d) the unit is dB for the transmission path loss when the distance between the interference transmitter and the interfered receiver is d;
L t the unit is dB for the feeder loss of the transmitting end;
L r the unit is dB for the feeder loss of a receiving end;
FDR (Δ f) is the frequency suppression factor in dB, defined as:
wherein:
p (f) is the power spectral density of the interference signal in W/kHz;
h (f) is the frequency response of the if filter of the victim receiver;
Δ f is the frequency interval between the disturbed receiver and the disturbing transmitter, and the unit is kHz; when delta f is 0, the signal is co-channel interference;
interference signal power
|H(f)| 2 The FDR (delta f) is more than or equal to 0 by reflecting the frequency spectrum template characteristic of the receiver;
the calculating of the background noise of the receiver specifically comprises:
receiver ground noise is mainly generated by the thermal motion of charged particles with the power:
N＝-174+10lgB+NF；
b is the medium frequency bandwidth with the unit of Hz, NF is the noise coefficient with the unit of dB;
calculating the transmission path loss when the distance between the interference transmitter and the interfered receiver is d according to the dry-to-noise ratio protection criterion, comprising
According to the dry-to-noise ratio protection criterion, INR is less than or equal to beta, beta is the INR protection requirement, and the unit is dB, then
The propagation model of the LTE system adopts an Omura HATA model to calculate the path loss, and the formula is as follows:
wherein L is p (d) The unit is a medium value of electric wave propagation loss of the quasi-smooth terrain, and is dB;f is the working frequency in MHz; h is 1 The effective height of the base station antenna is m; h is a total of 2 Is the effective height of the mobile station antenna, and the unit is m; d is the distance between the mobile station and the base station, and the unit is km; alpha (h) 2 ) Is the mobile station antenna height factor in dB;
for large cities alpha (h) 2 ) The expression of (c):
α(h 2 )＝3.2[lg(11.75h 2 )] 2 -4.97，f＞400MHz；
for suburban area alpha (h) 2 ) Expression (c):
calculating the space isolation and frequency isolation requirements required by the coexistence of the two systems according to a dry-to-noise ratio protection criterion, wherein the protection distance is as follows:
the guard distance d has a direct relationship with the frequency separation Δ f of the victim receiver from the disturber.
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| TD-LTE与异系统干扰共存研究;王韬;《中国优秀硕士学位论文全文数据库》;20160215;第3章 * |
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