MINISTRY OF EDUCATION AND TRAINING MINISTRY OF NATIONAL DEFENSE ACADEMY OF MILITARY SCIENCE AND TECHNOLOGY *************** NGO XUAN MAI SOLUTION FOR CORRECTING HETEROGENEITY BETWEEN CHANNELS ON PHASE ARRAY ANTENNA FOR SATELLITE POSITIONING RECEIVERS Specialization : Electronic engineering Code : 52 02 03 SUMMARY OF PhD THESIS IN TECHNICAL Hanoi, 2020 This Thesis has been completed at: Academy of Military Science and Technology, Ministry of Defense Scientific Supervisors: Assoc Prof Dr Nguyen Huy Hoang Dr Hoang The Khanh Reviewer 1: Prof Dr Bach Gia Duong Reviewer 2: Assoc Prof Dr Bui Ngoc My Reviewer 3: Dr Ta Chi Hieu This thesis was defendeb at the Doctoral Evaluating Council at Academy level held at Academy of Military Science and Technology at …… ,date 2020 This thesis can be found at: - The library of Academy of Military Science and Technology - Vietnam National Library INTRODUCTION Necessity of the thesis In recent years, the Global Navigation Satellite System - GNSS plays an important role, to be applied in almost all areas of social life, including Civil, industrial and national defense security However, the useful signal is transmitted from the GNSS satellites (about 20,000 km away from the earth) [4] spreading through the environment to the receiver input will be reduced dramatically (about 1024 times - 26dB) [5] due to many objective factors (extreme weather, shielded by obstructions, radio frequency interference) as well as subjective factors (interference, fake signal interference, interfering sources are created in electronic combat) [6] Therefore, the research of improving the anti-interference ability of GNSS receivers in order to ensure the ability to locate and guide exactly is always an urgent need, is being and continues to attract the attention of many scientists all over the world These types of noise are mainly broard-band noise, the only solution to be able to withstand these noise is to use phase array antennas The process of positioning and navigation signal on phase array antenna has brought a lot of benefits; however, it also incurred some technical issues that need to be addressed One of those problems is heterogeneity (in terms of phase, amplitude or both) between channels of phase array antennas This heterogeneity is usually expressed through group delay (Group Delay) [7] (Group delay is defined as the negative derivative (or slope) of a phase response versus frequency Different frequencies from input to output in a system) Stemming from the above reasons, the PhD student proposed using MPE standard [32] by the method of separate matrix vectors (SVD) instead of the standard MMSE used in [45] to solve the problem of correcting inhomogeneous channel errors on the phase array antenna to reduce the complexity of the algorithm and increase the convergence speed of the algorithm Due to the reduction of complexity in the implementation of the algorithm, the PhD student proposed to increase the number of phase array antenna elements to to increase the range of anti1 interference capabilities for satellite positioning receivers that are required for the system computation remains on board the same Objectives of the study The study proposes two solutions to correct heterogeneity between channels on phase array antennas based on self-compensation and two-stage correction using MPE optimization standard [32] instead of proposed MMSE standard in [45] to overcome the heterogeneity between receiving channels, improve the quality of signal to noise ratio (SINR), improve the reliability of satellite positioning receivers Objects and scopes of the study From the above analysis, the PhD student identified the object and scope of the thesis: GNSS satellite positioning receiver; 3, 4, and elements phase array antennas The thesis will focus on researching solutions to correct heterogeneity between receiver channels on and elements phase array antennas Research contents of the thesis - Study signal and noise model of GNSS system and receiver channel model of and elements phase array antennas Represents the satellite signal and noise of satellite positioning receiver on and elements phase array antennas under the influence of narrow and boardband noise - Building mathematical models of homogeneous and heterogeneous receiving channels for and elements phase array antennas - Simulate signal processing on and elements phase array antennas in the case of homogeneous and heterogeneous channels in order to assess the impact of heterogeneity on the anti-interference quality in signal processing - Study non-working zone and non-working zone's dependence on receiver sensitivity for and elements phase array antennas with distance between elements d=2/3.56 and d=/2 when the channel is homogeneous and inhomogeneous - Proposing the application of MPE optimization standard to replace MMSE standard for solutions to correction heterogeneity between channels on phase array antennas based on two-stage error channel correction algorithm and self-compensating error channel correction algorithm for the satellite positioning receiver - Perform tests on computers by simulation with Matlab software, evaluate the research results and the new proposals of the thesis compared with the previous results, from which give a number of recommendation with GNSS system model Research Methods To solve the above-mentioned contents, the PhD student conducts research on the theory of probability and mathematical statistics for radio techniques, coding and channel theory, linear algebra Based on the basic theories, build a mathematical model of the problem, thereby proposing solutions to correct heterogeneous error between the channels on the phase array antenna To verify and give visual results of the proposed method, the PhD student performed the calculation using Matlab software and was displayed in the form of a chart with different system parameters Scientific significance and practical meaning of the thesis - Scientific significance: The research results of the thesis are novelty, scientific, contributing more basis for the calculation, construction and design of satellite positioning systems on board The proposed solutions to correct heterogeneous error between channels on the phase array antennas are feasible, which is the initial basis for the research and development of satellite positioning systems, especially the satellite positioning systems on board such as UAVs, cruise missiles, and flying equipment in Vietnam - Practical significance: Solutions to correct heterogeneous errors between channels on phase array antennas combined with spatial - time signal processing methods to prevent interference, ensure accuracy and reliability for receiving satellite positioning signals on equipments, hightech equipment (CNC) using satellite positioning and navigation systems such as UAV, cruise missiles So, thesis: "The solution for correcting heterogeneity between channels on the phase array antenna for satellite positioning receivers" has high practical significance Contents of the thesis In addition to the introduction, conclusion, list of published works of the author, references, the content of the thesis consists of three chapters: Chapter 1: Overview of GNSS system and anti-interference solutions for positioning receivers Chapter 2: Study and evaluate the performance of antiinterferencing of MPE optimal standard for GNSS receiver Chapter 3: Solutions for correcting heterogeneous error between channels on the phase array antenna for satellite positioning receivers CHAPTER 1: OVERVIEW OF GNSS SYSTEM AND ANTIINTERFERENCE SOLUTIONS FOR POSITIONING RECEIVER 1.1 GNSS satellite position and navigation system, types of noise and signals in the system Global Navigation Satellite System structure Signal structure of GNSS system Nowaday, there are two most widely used satellite systems: Russia's GLONASS system and US’s GPS system In the scope of the thesis, the PhD focuses on solutions to correct heterogeneity error between channels on phase array antennas for satellite positioning receivers of the two systems 1.1.2.1 GPS signal structure 1.1.2.2 GLONASS signal structure 1.2 Noise types in GNSS systems In GNSS systems, since the useful signal transmitted from satellites to Earth is strongly degraded (26dB), this signal is very susceptible to interference by various objective and subjective factors These types of disturbances greatly affect GNSS signal reception, which can be classified into two types: natural noise (multi-path effect, atmospheric noise) and artificial noise (signal interference, noise interference ), is the cause of the deterioration of the system 1.3 Effective STAP processing techniques for GNSS system signals to enhance the anti-interference properties of recievers The commonly used optimum are maximize the SINR ratio on the output of adaptive phase array antennas MSE [19], МMSE [23], ML [23] and minimize power eigencanceler MPE by Singular Value Decomposition [32] 1.4 Existing methods for solving heterogeneous error correction issues Two-channel calibration method x1(t) 1(t ) K 1(jw) x2(t) 2 (t ) K tq (jw) K 2(jw) Fig 1.6 Spatial processing system two channels Two-channel self-compensating method L 1 Main channel ∑ Sub channel wL Output ∑ wk w2 w1 Fig 1.7 Two-channel self-compensating structure Noise compensation with one parameter correction x0(t) x1(t) K 0(jw) K 1(jw) × X  Ʃ w1 K 2(jw) × w2 Fig 1.9 Structure of noise compensation with one parameter correction 1.5 Parameters to assess the anti-interference quality Table 1.1 Characteristic of anti-interference quality 1.6 Math representation of anti-interference methods based on processing number of STAP signals The standard of space-time adaptation 1.6.1.1 Minimum mean square errors standard MMSE WMMSE  R1RA (1.1) 1.6.1.2 Minimum mean square errors standard according to limit condition     Wopt  R1  R A   CT R1R A C / CT R1C    (1.2) 1.6.1.3 Mean square errors standard (MSE) WMSE   R I  R n  W0 , 1 (1.3) 1.6.1.4 Minimize the output signal power of the adaptive phase array antenna according to limit condition Wopt   R I  R n  W0 1 (1.4) 1.6.1.5 Minimum power eigencanceler standard– MPE[32]   wMPE  Qv v QvH C CH Qv QvH C x1(n) w11 Z-1 w12 Z-1 w13 1 Z-1 Z-1 w1k-1 w1k Z-1 Z-1 w2k-1 w2k f (1.5) FIR ∑ x2(n) w21 Z-1 w22 Z-1 w23 ∑ y(n) ∑ xM(n) Z-1 wM1 wM2 Z-1 Z-1 wM3 wMk-1 Z-1 wMk ∑ Fig 1.13 Strucure of space-time filter Effective anti-jamming algorithms in GNSS systems 1.6.2.1 The algorithm of space-time according to the minimum of limited power The structure of space-time filter is shown above Fig 1.13 1.6.2.2 The space-time algorithm of minimum mean square deviation (MMSE) 1.7 Overview of domestic and foreign research on issues related research 1.8 Chapter conclusion On that basis, the PhD student has researched and assessed the anti-jamming effect of the MPE optimal standard for GNSS receiver on phase array antennas in chapter of the thesis and is the basis for proposing solutions to correction errors heterogeneity between channels on the phase array antenna in Chapter of the thesis CHAPTER 2: STUDY AND EVALUATE THE PERFORMANCE OF ANTIINTERFERCING OF MPE OPTIMAL STANDARD FOR GNSS RECEIVER 2.1 Signal and noise formation on the receiver elements of adaptive phase array antennas The formation of useful input signals x m   I x m   jQx m  (1.6) Noise model   I I (n )  Re exp  j I n t  j I      Q (n )  Im exp  j I n t  j I     I 2.2 Calculate transmission latency in the environment     (1.7) Fig 2.2 Array antenna geometry structure three elements x (m ) sin  cos   y(m ) sin  sin   (m )   (1.8)  c x (m ) cos  sin   2.3 Standardize signals and noise x norm (m, n)  x (m, n) (1.9) I2  Q2 2.4 Demonstration of noise and GNSS satellite signals on array antennas with elements and elements 1    A3 (, )   exp j 2 f0 2(R / c)sin  cos    / 3    exp  j 2 f0 2(R / c)sin  cos           ,        (1.10)       exp j 2 f0 2(R / c ) sin  cos   sin  sin       exp  j 2 f0 2(R / c )sin  cos      exp j 2 f0 2(R / c ) sin  cos   sin  sin     A9 (, )  exp  j 2 f0 2(R / c )sin  sin     exp j 2 f0 2(R / c )  sin  cos   sin  sin      exp  j 2 f0 2(R / c )( sin  cos )     exp j 2 f0 2(R / c ) sin  cos   sin  sin     exp  j 2 f0 2(R / c )( sin  sin )                                              (1.11) 2.5 Heterogeneous model of parameters on receiver channels of phase array antennas The group delay model of medium frequency filter Create white noise Normalize and add average values Low Pass Filter LPF Fig 2.8 Algorithm to create group delay  1, f  F am K LPF ( f )     0, f  Fam    f f g 0 ( f )  0   GD( f )df  0   GD(g )f In which f  200Hz Group Delay (2.24) (2.27) Fig 2.16 The working zone at the receiver protection factor is -30dB and 40dB - noise + In case there are two sources of interference: the elevation angle is 850, azimuths of noise sources are equally distributed Fig 2.18 The working zone at the receiver protection factor is -30dB and -40dB - noise  The non-working zones of GNSS receiver using elements adaptive phase array antenna For elements adaptive phase array antennas, PhD student also simulates the surface SINR ratio on the antenna output with the number of variable noise sources of 1, 2, 6, and create the non-working zone of GNSS receiver with receiver protection factor of -30dB and -40dB respectively With assumptions as in the case of elements antenna + In case there is only one source of interference: the elevation angle is 850, azimuths of noise sources are equally distributed Fig 2.21 The working zone at the receiver protection factor is -30dB and -40dB - noise 11 Fig 2.23 The working zone at the receiver protection factor is -30dB and -40dB - noise Fig 2.25 The working zone at the receiver protection factor is -30dB and -40dB - noise Fig 2.27 The working zone at the receiver protection factor is -30dB and -40dB - noise Compare non-working zones of GNSS receiver for elements adaptive phase array antenna with distance 2/3.56 Fig 2.29 The working zones at the receiver protection factor is -30dB - noise 12 Su phu thuoc vung khong lam viec vao ty so bao ve - anten phan tu 100 100 nhieu - lamda/2 nhieu - lamda/2 90 80 80 70 70 60 60 50 50 40 40 30 30 20 20 10 -15 Su phu thuoc vung khong lam viec vao ty so bao ve nhieu - d=2lamda/3.56 nhieu - d=2lamda/3.56 90 10 -20 -25 -30 -35 -15 -40 Ty so bao ve, dB -20 -25 -30 -35 -40 Ty so bao ve, dB Fig 2.30 Dependence of nonworking area on protection factor Fig 2.31 Dependence of nonworking area on protection factor in case d= /2 in case d= 2/3.56 % % Compare the non-working areas of GNSS receivers for anten and elements adaptive phase array antenna using the MPE standard Fig 2.33 Compare the nonFig 2.34 Compare the dependency working zone of the GNSS receiver of the non-working zone on the with the number of antenna receiver protection factor with and elements changed antenna elements Some conclusions about working zone of the phase array antenna 2.8 Evaluate the quality of signal reception on elements adaptive phase array antenna when the channel is heterogeneous Evaluate the signal reception quality when the channel is heterogeneous in phase The results are simulated with the case that the receiver channel is not distorted (homogeneous) and heterogeneous in phase between the receiver channels and the phase amplitude changes respectively: 50 and 100 13 He so nen cong suat nhieu 70 Ty so SINR dau 60 -10 25dB 50 15dB -20 40 30 -30 20 MMSE - Dong nhat MPE - Dong nhat MMSE - BĐN pha - DltPh0=5 MPE - BĐN pha - DltPh0=5 MMSE - BĐN Pha - DlePh0=10 MPE - BDN Pha - DltPh0=10 10 -40 MMSE - Dong nhat MPE - Dong nhat MMSE - BĐN - DltPh0=5 MPE - BĐN - DltPh0=5 MMSE - BĐN Pha - Dltpha =10 MPE - BĐN Pha - Dltpha =10 -50 -10 -60 So buoc tinh toan 10 12 10 4 So buoc tinh toan 10 12 104 Fig 2.35 Compare noise Fig 2.36 Compare the SINR compression coefficient when ratio when heterogeneous in heterogeneous in phase phase Evaluate the quality of the signal reception when channel is heterogeneous in amplitude Simulate anti-jamming characteristics when has heterogeneous between channels on phase array antennas with two optimal standards MMSE and MPE compared to cases when the receiver channel uses elements adaptive phase array antennas Fig 2.37 Compression ratio when there is distortion of 0.1 Fig 2.38 Output SINR ratio when there is distortion of 0.1 Fig 2.39 Compression ratio when Fig 2.40 Output SINR ratio when there is distortion of 0.5 there is distortion of 0.5 2.8.3 Compare the working zone of GNSS receiver when the channel is heterogeneous with a elements phase array antenna 2.9 Evaluate the convergence of the algorithm through the number of adaptive steps 14 2.10 Conclusion of chapter Chapter has modeled GNSS signal, noise and receiver channel of array antenna and elements Simulate anti-jamming characteristics such as: Noise compression ratio; SINR ratio on the antenna output and develop a schematic, non-working area of the GNSS receiver for and elements adaptive phase array antennas Comparing and evaluating the above parameters with the and elements antenna model has been studied in the project [45] From that, we can conclude that the elements adaptive phase array antenna has the best anti-interference quality Thereby, as a basis for evaluating and proposing methods to correct heterogeneity errors between receivers for satellite-receiver receivers presented in Chapter of the thesis CHAPTER 3: SOLUTIONS FOR CORRECTING HETEROHENEOUS ERROR BETWEEN CHANNELS ON PHASE ARRAY ANTENNA FOR SATELLITE POSITIONING RECEIVERS As mentioned, the heterogeneity between the channels on the phase array antenna has a great influence on the reception quality, reducing the reliability of satellite positioning receivers To overcome the effects of this heterogeneity, it is necessary to design a multi-channel antijamming filter with the automatic error correction function Chapter will propose the use of an MPE optimum standard (with lower computational complexity, faster algorithm convergence) instead of the MMSE optimization standard used in [45] and the use of antennas elements replacement for elements antenna (more resistant to interference and non-working area also optimized than antenna and elements) 3.1 Two-stage error channel correction method using MPE standard Model, structure method The structure of two-stage filter based on auto-correction and algorithm flowchart to calculate receiver anti-jamming characteristics using the above algorithm turn is shown in Fig 3.1 and Fig 3.2 15 SF x1(n) Z-1 w11 w12 Z-1 Z-1 Z-1 w1N-1 w13 FIR w1N k1 ∑ x2(n) Z-1 w21 w22 Z-1 w23 TF Z-1 Z-1 w2N-1 w2N y(n) k2 ∑   xM(n) Z-1 wM2 wM1 Z-1 Z-1 Z-1 wMN-1 wM3  wMN kM ∑  ∑ MPE optimal standrad Fig 3.1 Two-stage filter structure based on auto-correction The output of this filter is represented by the formula: M N i 1 j 1 y n    ki (n) vij x n  j  1 (3.1) The result is: W  VK (3.7) W0  CST (CTST CST )1b1 (3.8) 16 Begin Enter the input parameters of the system Formation of input effects during processing period Add heterogeneity on the receiver channel Set statistics to jT=1 jT=jT+1 No jT ≥ NumTest Two-stage error channel correction method using MPE standard Yes Calculation of anti-jamming properties on antenna output Display results and draw figures End Fig 3.2 Flowchart of Two-stage error channel correction algorithm using MPE standard 17 Stage of signal space processing (automatic error correction) Step 1: The signal at the output of the interferer is described by the following matrix: y(1)  WT (1)X(1) (3.11) y(r )  WT (r )X(r ) (3.13) Step r  q : Stage of signal time processing (giai đoạn vận hành) Step q  : The output of the space - time filter is described by the matrix system: y(q  1)  ZT (q  1)K(q  1) (3.14) Step r  q  q  p : The output of the space - time filter is described by the matrix system: y(r )  ZT (r )K(r ) (3.19) Simulation results of two-stage error channel correction method based on auto-correction using MPE standard To evaluate the signal reception quality of GNSS receivers when using the two-stage MPE error correction method on the basis of selfcompensation to correct heterogeneous errors between channels on the phase array antenna PhD student simulates the anti-interference characteristics of GNSS receivers when applying the above method in the case of homogeneous and heterogeneous channels He so nen cong suat nhieu thuat toan xu ly khong gian - thoi gian 90 -10 80 -15 Ty so SINR dau -20 70 15dB 7dB -25 60 10dB -30 50 30dB 50dB -35 40 -40 30 -45 MMSE - Dong nhat MPE - Dong nhat MMSE - BĐN - Co hieu chinh MPE - BĐN - Co hieu chinh MMSE - Khong hieu chinh 20 10 MMSE - Dong nhat MPE - Dong nhat MMSE - BĐN - Co hieu chinh MPE - BĐN - Co hieu chinh MMSE - BĐN - Khong hieu chinh -50 -55 -60 So buoc tinh toan 10 12 104 So buoc tinh toan (a) (b) 18 10 12 104 Fig 3.2 Noise compression factor and SINR ratio situation He so nen cong suat nhieu thuat toan xu ly khong gian - thoi gian 90 -10 80 -15 Ty so SINR dau -20 70 -25 60 9dB -30 50 -35 40 -40 30 MMSE - Dong nhat MPE - Dong nhat MMSE - BĐN - Co hieu chinh MPE - BĐN - Co hieu chinh MMSE - BĐN - Khong hieu chinh -45 MMSE - Dong nhat MPE - Dong nhat MMSE - BĐN - Co hieu chinh MPE - BĐN - Co hieu chinh MMSE - Khong hieu chinh 20 10 -50 -55 -60 10 12 104 So buoc tinh toan 10 12 104 So buoc tinh toan (a) (b) Fig 3.3 Noise compression factor and SINR ratio situation He so nen cong suat nhieu thuat toan xu ly khong gian - thoi gian 70 Ty so SINR dau 60 -10 50 -20 40 -30 30 -40 20 MMSE - Dong nhat MPE - Dong nhat MMSE - BĐN - Co hieu chinh MPE - BĐN - Co hieu chinh MMSE - Khong hieu chinh -50 MMSE - Dong nhat MPE - Dong nhat MMSE - BĐN - Co hieu chinh MPE - BĐN - Co hieu chinh MMSE - Khong hieu chinh 10 -60 -10 -70 10 12 10 So buoc tinh toan 10 12 10 So buoc tinh toan (a) (b) Fig 3.4 Noise compression factor and SINR ratio situation He so nen cong suat nhieu thuat toan xu ly khong gian - thoi gian 40 -15 35 -20 Ty so SINR dau -25 30 -30 25 -35 20 -40 15 -45 MMSE - BĐN - TH1 MPE - BĐN - TH1 MMSE - BĐN - TH4 MPE - BĐN - TH4 10 MMSE - BĐN - TH1 MPE - BĐN - TH1 MMSE - BĐN - TH4 MPE - BĐN - TH4 -50 -55 -60 10 12 10 So buoc tinh toan 10 12 104 So buoc tinh toan (a) (b) Fig 3.5 Noise compression factor and SINR ratio situation He so nen cong suat nhieu thuat toan xu ly khong gian - thoi gian 35 -15 30 -20 Ty so SINR dau -25 25 -30 20 -35 15 -40 10 -45 MMSE - TH3 MPE - TH3 MMSE - TH5 MPE - TH5 MMSE - TH3 MPE - TH3 MMSE - TH5 MPE - TH5 -50 -55 -5 -60 So buoc tinh toan 10 12 10 4 So buoc tinh toan 10 12 104 (a) (b) Fig 3.6 Noise compression factor and SINR ratio situation Statistics of simulation results 19 3.2 Self-compensating error channel correction method using MPE standard Model, structure method x1(n) Z-1 w11=1 Z-1 w12=1 Z-1 w13=1 w1N-1=1 Z-1 FIR w1N=1 ∑ x2(n) Z-1 w21 Z-1 w22 Z-1 Z-1 w23 w2N-1 w2N k2 ∑   xM(n) Z-1 wM1 Z-1 wM2 Z-1 wM3 wMN-1   y(n) ∑ Z-1 wMN kM ∑ MPE optimal standrad Fig 3.10 Automatic noise compensation structure with calibration of heterogeneous channels on phase array antenna The output of this filter is represented by the formula: M N i 1 j 1 y n    ki (n ) vij x n  j  1 (3.22) The expression (3.22) will be rewritten in vector form y(n)  XT W (3.23) W  V K (3.24) In which: 20 Begin Enter the input parameters of the system Formation of input effects during processing period Add heterogeneity on the receiver channel Set statistics to jT=1 jT=jT+1 No jT ≥ NumTest Self-compensating error channel correction method using MPE standard Yes Calculation of anti-jamming properties on antenna output Display results and draw figures End Fig 3.11 Flowchart of self-compensating error channel correction algorithm 21 The structure of the automatic noise compensator with the correction of heterogeneous receiver channels and algorithm flowchart to calculate receiver anti-jamming characteristics using the above algorithm turn is shown in Fig 3.10 and 3.11 Simulate and evaluate the results of error correction methods in different cases He so nen nhieu 100 Ty so SINR dau – tu bu tru -10 90 -15 80 -20 70 -25 60 Dong nhat BĐN - Khong bu tru BĐN - Co bu tru - MMSE BĐN - Co bu tru - MPE 50 -30 -35 40 Dong nhat BĐN - Khong bu tru BĐN - Co bu tru - MMSE BĐN - Co bu tru - MPE -40 -45 30 -50 10 12 104 So buoc tinh toan 10 12 10 So buoc tinh toan (a) (b) Fig 3.10 Noise compression factor and output SINR ratio situation He so nen nhieu 50 Ty so SINR dau – tu bu tru -10 nhieu nhieu nhieu 45 -15 40 -20 35 -25 30 -30 25 nhieu nhieu nhieu -35 20 -40 10 12 104 So buoc tinh toan 10 12 10 So buoc tinh toan (a) (b) Fig 3.11 Noise compression factor and SINR ratio situation He so nen nhieu 70 Ty so SINR dau – tu bu tru -10 BĐN - MPE - 15dB BĐN - MPE - 40dB 65 -15 60 55 -20 50 -25 45 -30 40 -35 -40 35 BĐN - MPE - 15dB BĐN - MPE - 40dB -45 30 -50 So buoc tinh toan 10 12 14 104 10 12 So buoc tinh toan (a) (b) Fig 3.12 Noise compression factor and SINR ratio situation 22 14 10 He so nen nhieu Ty so SINR dau – tu bu tru -10 nhieu - TH4 nhieu - 40dB -15 -20 -25 -30 -35 101 -40 nhieu - TH4 nhieu - 40dB -45 -50 So buoc tinh toan 10 12 104 So buoc tinh toan 10 12 10 (а) (b) Fig 3.13 Noise compression factor and SINR ratio situation 3.3 Evaluate the working zone of GNSS receiver when correction heterogeneity error 3.4 Conclusion of chapter In this chapter, it is proposed to improve methods of correcting heterogeneity between receivers on adaptive phase array antennas using MPE adaptive standard instead of MMSE standard proposed in the project [45] Through simulation and analysis results for different signal and noise simulation situations, it is shown that the proposed methods have better efficiency, faster algorithm convergence speed When applying a twostage error correction method on the basis of self calibration as well as a self-compensation method with a elements adaptive phase array antenna to the MPE standard for both homogeneous and non-homogeneous channels, then depending on different situations noise ratio SINR better than standard MMSE from 2dB to 5dB CONCLUSION A) The main results of the thesis Building mathematical models of signals in GNSS systems under the influence of broad-band noise and narrow-band noise Simulate and calculate the non-working zone of the GNSS receivers by constructing graphs of the SINR ratio on outputting of phase array antenna with and elements, the dependency of the non-working zone on the receiver protection factor Proposed methods to correct heterogeneous channel errors on elements phase array antenna with the distance between the elements is 23 d= 2/3.56 by using the MPE standard to replace the MMSE standard proposed in the project [40] B) Main contributions of the thesis: 1) Foundation, simulated and evaluated the non-working area of the GNSS receiver with the MPE optimal standard and the effects of the heterogeneity between channels on the phase array antenna to the antiinterference quality of GNSS system with elements phase array antenna 2) Proposed a solution to correct heterogeneous errors between channels on phase array antennas for GNSS receivers by two-stage selfcorrection method and self-compensating method with MPE on Singular Value Decomposition C) Future work Through the research results and new contributions of the thesis, the PhD student proposed using elements phase array antennas with the distance between antenna elements is 2/3.56 combined with two methods to correct heterogeneous errors between channels on phase array antennas have been proposed for GNSS receivers, especially for devices on the cabin In limited conditions, the PhD student has only conducted empirical survey with simulation techniques with specific signal and noise situations The future work of the thesis should realize research results on hardware and empirical survey in practice The results of the thesis can be developed in applications for receivers of position and navigation systems on the cabin 24 LIST OF PUBLICATIONS Ngo Xuan Mai, Hoang The Khanh, Le Ky Bien, “Non-Working zones in GNSS at interference protection” Антенны, p.37-47, № 4.2017 Ngo Xuan Mai, Hoang The Khanh, Nguyen Huy Hoang, “Noneworking zone of GNSS’s receiver with phase array antenna of elements”, Journal of Military Research and Technology, 2/2018, code: ISSN 1859 - 1043, p.61-70 Ngo Xuan Mai, Hoang The Khanh, Nguyen Huy Hoang, Le Thi Trang (8/2018), “Research on the impact of channel heterogeneity on the antiinterference efficiency on the phase array antenna with GPS/GLONASS systems”, FEE national conference, “Application of high technology into practice”, Journal of Military Research and Technology, 8/2018, code: ISSN 1859 – 1043, p.164-171 Ngo Xuan Mai, Phung Quang Thanh, Hoang The Khanh, Nguyen Huy Hoang, “Proposed methods for heterogeneous error correction of receive channel for GNSS anti-interference devices”, Journal of Military Research and Technology, 5/2019, code: ISSN 1859 – 1043, p.7-20 Ngo Xuan Mai, Hoang The Khanh, Nguyen Huy Hoang (8/2019) “ Proposed Methods for heterogenous error corection of receive channel for GNSS receiver devices with MPE”, Journal of Military Research and Technology, 8/2019, code: ISSN 1859 – 1043, p.53-65 25 ... the phase array antenna to the antiinterference quality of GNSS system with elements phase array antenna 2) Proposed a solution to correct heterogeneous errors between channels on phase array antennas... adaptive phase array antenna with distance 2/3.56 Fig 2.29 The working zones at the receiver protection factor is -30dB - noise 12 Su phu thuoc vung khong lam viec vao ty so bao ve - anten phan... BĐN pha - DltPh0=5 MPE - BĐN pha - DltPh0=5 MMSE - BĐN Pha - DlePh0=10 MPE - BDN Pha - DltPh0=10 10 -40 MMSE - Dong nhat MPE - Dong nhat MMSE - BĐN - DltPh0=5 MPE - BĐN - DltPh0=5 MMSE - BĐN Pha