System parameter determination method of CDMA communication system

Abstract

The invention belongs to the technical field of parameter determination methods, and particularly relates to a system parameter determination method of a CDMA (code division multiple access) communication system, which comprises the following steps: S1, a parameter estimation method: S11, acquiring carrier frequency and code rate of a CDMA signal, performing down-conversion and down-sampling processing on a primary satellite signal to obtain a chip-level signal, estimating signal out-of-step time by using a Frobenius norm method, and determining a CDMA signal according to the estimated signal out-of-step time; according to the chip-level signal, the signal out-of-step time and a pre-acquired spreading code sequence library, performing parallel correlation de-spreading processing on all spreading code sequences; s2, a parameter calibration method; and S3, a parameter determination method. In the invention, the communication system parameter is determined from the obtained first indication information of the CDMA communication system parameter, and the communication system parameter is determined according to the mapping relation between the communication system parameter and the influence factor and the communication system parameter, so that the situation that the receiving end equipment searches the communication system parameter in a blind detection mode is avoided; therefore, the workload of the receiving end equipment can be reduced, and the communication efficiency is improved.

Description

Technical Field

[0001] The invention relates to a parameter determination method, in particular to a system parameter determination method for a CDMA communication system. Background Art

[0002] The mobile communication network is a constantly changing network, involving the following contents: network structure, user distribution in the wireless environment, and usage behavior. At the same time, with the expansion of network scale, the complexity of network coverage planning scale, and the changes in network traffic model and business model, the current performance and operation of the network will deviate from the original design requirements. These all require continuous adjustment of the network through network optimization to adapt to various changes. The above situation shows that network optimization is a long-term and continuous system engineering, which requires continuous exploration and accumulation of experience; only by solving various problems in the network, optimizing network resource allocation, improving the network operation environment, and improving the network operation quality can the network run in the best state and provide strong technical support and network support for the rapid development of mobile communication services.

[0003] For CDMA mobile communication systems, network optimization is more important because CDMA mobile communication systems are interference-limited communication systems. The capacity of the system is soft capacity. Network optimization can not only improve network performance and service quality, but also increase system capacity. Strengthening network optimization, improving network operation efficiency, and achieving improvements in service level, service quality, operating efficiency, and competitiveness have become real user needs.

[0004] In a CDMA communication system, when a transmitting device sends information to a receiving device, it needs to use communication system parameters to encode the information and send it to the receiving device through a sidelink channel. Correspondingly, when the receiving device receives the information transmitted by the transmitting device through the sidelink channel, it needs to use the same communication system parameters as those encoded by the transmitting device to decode the information carried by the sidelink channel. However, the receiving device does not know the specific parameter values ​​of the communication system parameters used by the transmitting device. In the prior art, after receiving the information, the receiving device generally determines the decoded communication system parameters by blind detection. However, the use of blind detection will greatly increase the workload of the receiving device, making the decoding of the receiving device more complex.

[0005] In view of this, the present invention designs a method for determining system parameters of a CDMA communication system. Summary of the invention

[0006] The main purpose of the present disclosure is to provide a method for determining system parameters of a CDMA communication system, so as to effectively solve the problems raised by the inventor in the above background technology.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A method for determining system parameters of a CDMA communication system comprises the following steps:

[0009] S1: parameter estimation method, the parameter estimation method comprising:

[0010] S11: Acquire the carrier frequency and code rate of the CDMA signal, perform down-conversion and down-sampling processing on the primary satellite signal to obtain a chip-level signal, use the Frobenius norm method to estimate the signal desynchronization time, perform parallel correlation despreading processing on all spread spectrum code sequences according to the chip-level signal, signal desynchronization time and the pre-acquired spread spectrum code sequence library, normalize the despread signal and calculate the signal power;

[0011] S12: Determine whether the calculated power has a signal power value greater than a power threshold value;

[0012] S13: Filter the spread spectrum code sequence of the user corresponding to the signal power value, and update the spread spectrum code sequence library, reconstruct the user signal according to the signal desynchronization time and the filtered spread spectrum code sequence, subtract the reconstructed user signal from the CDMA signal, offset it within a set range according to the signal desynchronization time, and perform parallel correlation despreading processing on all the spread spectrum code sequences in the spread spectrum code sequence library, normalize the despread signal and calculate the signal power;

[0013] S14: Determine whether the calculated power has a signal power value greater than a power threshold value;

[0014] S15: Calculate the time-frequency difference between the reconstructed signal of each user and the CDMA signal of the primary satellite to obtain the time-frequency difference estimation result of each user;

[0015] S2: parameter calibration method, the parameter calibration method comprising:

[0016] S21: measuring the signal, signal power, and signal noise power of the CDMA communication system at the first to fourth calibration reference planes, and calculating the signal bit error rate and signal-to-noise ratio at the second calibration reference plane and the fourth calibration reference plane, and calculating the spectrum efficiency and energy efficiency at the first calibration reference plane;

[0017] S22: adjusting the transmission signal of the CDMA signal system according to the signal bit error rate, signal-to-noise ratio, spectrum efficiency and energy efficiency;

[0018] S23: adjusting the transmission signals of the transmitting part and the receiving part of the CDMA signal system;

[0019] S24: outputting a bit error rate and signal-to-noise ratio corresponding relationship curve, a bit error rate and spectrum efficiency corresponding relationship curve, and a bit error rate and energy efficiency corresponding relationship curve according to the signal bit error rate, signal-to-noise ratio, spectrum efficiency, and energy efficiency;

[0020] S3: parameter determination method, the parameter determination method comprising:

[0021] S31: determining system parameters of the CDMA signal system according to the acquired signal data or according to a mapping relationship between influencing factors of the system parameters and communication system parameters to determine system parameters of the CDMA signal system;

[0022] S32: The communication system parameters include the subcarrier spacing SCS of the sidelink channel, and the communication system parameters are used to decode the signal carried on the sidelink channel;

[0023] S33: The communication system parameters also include the cyclic prefix CP or bandwidth part of the Sidelink channel;

[0024] S34: The communication system parameters include a first communication system parameter and a second communication system parameter for decoding a signal carried on a physical sidelink control channel.

[0025] Preferably, in the step S34, if the acquired system parameters correspond to the first communication system parameters, the indication information is acquired from the network message sent by the network side device.

[0026] Preferably, in step S34, if the indication information matches the second communication system parameter, the indication information is obtained in the following manner: obtained from a network message sent by a network side device; obtained from information obtained by decoding the side link control information SCI carried on the physical side link control channel by the first communication system parameter.

[0027] Preferably, in step S11, the obtained chip-level signal is overlapped and segmented according to a length of twice the spread spectrum gain to obtain an observation vector matrix with rows and columns twice the size of the spread spectrum gain, and a search is performed along the diagonal of the observation vector matrix to obtain a matrix with rows and columns equal to the size of the spread spectrum gain, and the delay corresponding to the maximum value of the second-order norm of the matrix is ​​taken as the estimated signal desynchronization time.

[0028] Preferably, in step S11, all spread spectrum code sequences are subjected to correlation despreading processing according to the chip-level signal, the signal desynchronization time and the spread spectrum code sequence library to obtain the despread signal and express it as

[0029]

[0030] Its i(t) represents the despread signal, x(t) represents the baseband CDMA signal, T c represents the chip period, P represents the spread spectrum chip number, represents the i-th spreading code sequence in the spreading code sequence library, represents the estimated signal desynchronization time of the kth user;

[0031] In the step S11, the despread signal is normalized according to its maximum value.

[0032] Preferably, the signal power value determined in step S12 corresponds to the out-of-sync time of the user and a corresponding spread spectrum code sequence is obtained, and then the spread spectrum code sequence of the user is removed from the spread spectrum sequence library to obtain an updated spread spectrum code sequence library.

[0033] Preferably, in step S21, before calculating the signal bit error rate and signal-to-noise ratio at the second calibration reference plane and the fourth calibration reference plane, the signals measured at the first calibration reference plane and the second calibration reference plane are phase aligned, and the two aligned measurement signals are demodulated respectively to obtain a transmitted signal sequence and a received signal sequence.

[0034] Preferably, in step S23, the transmission signal fed back by the CDMA signal system is adjusted to be stable.

[0035] Preferably, the network message is any one of a system broadcast SI message, a radio resource control RRC message and a downlink control message DCI.

[0036] In view of this, compared with the prior art, the beneficial effects of the present invention are:

[0037] (I) In the present application, the disadvantage of mutual interference between multiple users can be effectively solved, the multi-peak ambiguity phenomenon can be avoided, the main satellite CDMA signal is despread and reconstructed, and the accuracy of estimating the despread synchronization position of each CDMA user signal under low signal-to-noise ratio can be effectively improved.

[0038] (ii) In the present application, the signal bit error rate, signal-to-noise ratio, spectrum efficiency, energy efficiency, etc. are calculated to calibrate the transmission signals of the transmitting part and the receiving part, thereby controlling the signals of the transmitting part and the receiving part in the CDMA communication system with higher quality and realizing feedback correction of the communication link.

[0039] (III) In the present application, the communication system parameters are determined from the first indication information of the acquired CDMA communication system parameters, and the communication system parameters are determined according to the mapping relationship between the communication system parameters, the influencing factors and the communication system parameters, thereby avoiding the receiving device from searching for the communication system parameters by blind detection, thereby reducing the workload of the receiving device and improving communication efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Shown is a flow chart of a method for determining system parameters of a CDMA communication system provided by the present invention;

[0041] Figure 2 Shown is a flow chart of the parameter estimation method;

[0042] Figure 3 Shown is a flow chart of a parameter calibration method;

[0043] Figure 4 Shown is a flow chart of the parameter determination method. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] See also Figure 1-4 , the present invention provides the following embodiments:

[0046] A method for determining system parameters of a CDMA communication system comprises the following steps:

[0047] S1: parameter estimation method, the parameter estimation method comprising:

[0048] S11: Acquire the carrier frequency and code rate of the CDMA signal, perform down-conversion and down-sampling processing on the primary satellite signal to obtain a chip-level signal, use the Frobenius norm method to estimate the signal desynchronization time, perform parallel correlation despreading processing on all spread spectrum code sequences according to the chip-level signal, signal desynchronization time and the pre-acquired spread spectrum code sequence library, normalize the despread signal and calculate the signal power;

[0049] S12: Determine whether the calculated power has a signal power value greater than a power threshold value;

[0050] S13: Filter the spread spectrum code sequence of the user corresponding to the signal power value, and update the spread spectrum code sequence library, reconstruct the user signal according to the signal desynchronization time and the filtered spread spectrum code sequence, subtract the reconstructed user signal from the CDMA signal, offset it within a set range according to the signal desynchronization time, and perform parallel correlation despreading processing on all the spread spectrum code sequences in the spread spectrum code sequence library, normalize the despread signal and calculate the signal power;

[0051] S14: Determine whether the calculated power has a signal power value greater than a power threshold value;

[0052] S15: Calculate the time-frequency difference between the reconstructed signal of each user and the CDMA signal of the primary satellite to obtain the time-frequency difference estimation result of each user;

[0053] S2: parameter calibration method, the parameter calibration method comprising:

[0054] S21: measuring the signal, signal power, and signal noise power of the CDMA communication system at the first to fourth calibration reference planes, and calculating the signal bit error rate and signal-to-noise ratio at the second calibration reference plane and the fourth calibration reference plane, and calculating the spectrum efficiency and energy efficiency at the first calibration reference plane;

[0055] S22: adjusting the transmission signal of the CDMA signal system according to the signal bit error rate, signal-to-noise ratio, spectrum efficiency and energy efficiency;

[0056] S23: adjusting the transmission signals of the transmitting part and the receiving part of the CDMA signal system;

[0057] S24: outputting a bit error rate and signal-to-noise ratio corresponding relationship curve, a bit error rate and spectrum efficiency corresponding relationship curve, and a bit error rate and energy efficiency corresponding relationship curve according to the signal bit error rate, signal-to-noise ratio, spectrum efficiency, and energy efficiency;

[0058] S3: parameter determination method, the parameter determination method comprising:

[0059] S31: determining system parameters of the CDMA signal system according to the acquired signal data or according to a mapping relationship between influencing factors of the system parameters and communication system parameters to determine system parameters of the CDMA signal system;

[0060] S32: The communication system parameters include the subcarrier spacing SCS of the sidelink channel, and the communication system parameters are used to decode the signal carried on the sidelink channel;

[0061] S33: The communication system parameters also include the cyclic prefix CP or bandwidth part of the Sidelink channel;

[0062] S34: The communication system parameters include a first communication system parameter and a second communication system parameter for decoding a signal carried on a physical sidelink control channel.

[0063] Specifically, in step S34, if the acquired system parameters correspond to the first communication system parameters, the indication information is acquired from the network message sent by the network side device.

[0064] Specifically, in step S34, if the indication information matches the second communication system parameter, the indication information is obtained in the following manner: obtained from a network message sent by a network side device; obtained from information obtained by decoding the side link control information SCI carried on the physical side link control channel from the first communication system parameter.

[0065] Specifically, in step S11, the obtained chip-level signal is overlapped and segmented according to a length of twice the spread spectrum gain to obtain an observation vector matrix with rows and columns twice the size of the spread spectrum gain. A search is performed along the diagonal of the observation vector matrix to obtain a matrix with rows and columns equal to the size of the spread spectrum gain. The delay corresponding to the maximum value of the second-order norm of the matrix is ​​taken as the estimated signal desynchronization time.

[0066] Specifically, in step S11, all spread spectrum code sequences are subjected to correlation despreading processing according to the chip-level signal, the signal desynchronization time and the spread spectrum code sequence library to obtain the despread signal and express it as

[0067]

[0068] Its i (t) represents the despread signal, x(t) represents the baseband CDMA signal, T c represents the chip period, P represents the spread spectrum chip number, represents the i-th spreading code sequence in the spreading code sequence library, represents the estimated signal desynchronization time of the kth user;

[0069] In step S11, the despread signal is normalized according to its maximum value.

[0070] Specifically, the corresponding spreading code sequence is obtained according to the desynchronization time of the user corresponding to the signal power value determined in step S12, and then the spreading code sequence of the user is removed from the spreading code library to obtain an updated spreading code sequence library.

[0071] Specifically, in step S21, before calculating the signal bit error rate and signal-to-noise ratio at the second calibration reference plane and the fourth calibration reference plane, the signals measured at the first calibration reference plane and the second calibration reference plane are phase aligned, and the two aligned measurement signals are demodulated respectively to obtain a transmitted signal sequence and a received signal sequence.

[0072] Specifically, in step S23, the transmission signal fed back by the CDMA signal system is adjusted to be stable.

[0073] Specifically, the network message is any one of a system broadcast SI message, a radio resource control RRC message, and a downlink control message DCI.

[0074] The specific implementation methods of this embodiment are as follows: effectively solving the disadvantage of mutual interference between multiple users, avoiding the multi-peak ambiguity phenomenon, despreading and reconstructing the main satellite CDMA signal, and effectively improving the accuracy of estimating the despreading synchronization position of each CDMA user signal under low signal-to-noise ratio; calculating the signal bit error rate, signal-to-noise ratio, spectrum efficiency, energy efficiency, etc. to calibrate the transmission signals of the transmitting part and the receiving part, and then controlling the signals of the transmitting part and the receiving part in the CDMA communication system with higher quality, and realizing feedback correction of the communication link; determining the communication system parameters from the first indication information of the acquired CDMA communication system parameters, and determining the communication system parameters according to the mapping relationship between the communication system parameters and the influencing factors and the communication system parameters, avoiding the receiving end device from searching for the communication system parameters by blind detection, thereby reducing the workload of the receiving end device and improving the communication efficiency.

[0075] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0076] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for determining system parameters of a CDMA communication system, characterized in that: The following steps are involved: S1: parameter estimation method, the parameter estimation method comprising: S11: Acquire the carrier frequency and code rate of the CDMA signal, perform down-conversion and down-sampling processing on the primary satellite signal to obtain a chip-level signal, use the Frobenius norm method to estimate the signal desynchronization time, perform parallel correlation despreading processing on all spread spectrum code sequences according to the chip-level signal, signal desynchronization time and the pre-acquired spread spectrum code sequence library, normalize the despread signal and calculate the signal power; S12: Determine whether the calculated power has a signal power value greater than a power threshold value; S13: Filter the spread spectrum code sequence of the user corresponding to the signal power value, and update the spread spectrum code sequence library, reconstruct the user signal according to the signal desynchronization time and the filtered spread spectrum code sequence, subtract the reconstructed user signal from the CDMA signal, offset it within a set range according to the signal desynchronization time, and perform parallel correlation despreading processing on all the spread spectrum code sequences in the spread spectrum code sequence library, normalize the despread signal and calculate the signal power; S14: Determine whether the calculated power has a signal power value greater than a power threshold value; S15: Calculate the time-frequency difference between the reconstructed signal of each user and the CDMA signal of the primary satellite to obtain the time-frequency difference estimation result of each user; S2: parameter calibration method, the parameter calibration method comprising: S21: measuring the signal, signal power, and signal noise power of the CDMA communication system at the first to fourth calibration reference planes, and calculating the signal bit error rate and signal-to-noise ratio at the second calibration reference plane and the fourth calibration reference plane, and calculating the spectrum efficiency and energy efficiency at the first calibration reference plane; S22: adjusting the transmission signal of the CDMA signal system according to the signal bit error rate, signal-to-noise ratio, spectrum efficiency and energy efficiency; S23: adjusting the transmission signals of the transmitting part and the receiving part of the CDMA signal system; S24: outputting a bit error rate and signal-to-noise ratio corresponding relationship curve, a bit error rate and spectrum efficiency corresponding relationship curve, and a bit error rate and energy efficiency corresponding relationship curve according to the signal bit error rate, signal-to-noise ratio, spectrum efficiency, and energy efficiency; S3: parameter determination method, the parameter determination method comprising: S31: determining system parameters of the CDMA signal system according to the acquired signal data or according to a mapping relationship between influencing factors of the system parameters and communication system parameters to determine system parameters of the CDMA signal system; S32: The communication system parameters include the subcarrier spacing SCS of the sidelink channel, and the communication system parameters are used to decode the signal carried on the sidelink channel; S33: The communication system parameters also include the cyclic prefix CP or bandwidth part of the Sidelink channel; S34: The communication system parameters include a first communication system parameter and a second communication system parameter for decoding a signal carried on a physical sidelink control channel.

2. The method for determining system parameters of a CDMA communication system according to claim 1, characterized in that: In the step S34, if the acquired system parameters correspond to the first communication system parameters, the indication information is acquired from the network message sent by the network side device.

3. The method for determining system parameters of a CDMA communication system according to claim 2, characterized in that: In the step S34, if the indication information matches the second communication system parameter, the indication information is obtained in the following manner: obtained from a network message sent by a network side device; obtained from information obtained by decoding the side link control information SCI carried on the physical side link control channel from the first communication system parameter.

4. The method for determining system parameters of a CDMA communication system according to claim 1, characterized in that: In the step S11, the obtained chip-level signal is overlapped and segmented according to a length of twice the spread spectrum gain to obtain an observation vector matrix with rows and columns twice the size of the spread spectrum gain. A search is performed along the diagonal of the observation vector matrix to obtain a matrix with rows and columns equal to the size of the spread spectrum gain. The delay corresponding to the maximum value of the second-order norm of the matrix is ​​taken as the estimated signal desynchronization time.

5. The method for determining system parameters of a CDMA communication system according to claim 4, characterized in that: In step S11, all spread spectrum code sequences are subjected to correlation despreading processing according to the chip-level signal, the signal desynchronization time, and the spread spectrum code sequence library to obtain the despread signal and express it as Its i (t) represents the despread signal, x(t) represents the baseband CDMA signal, T c represents the chip period, P represents the spread spectrum chip number, represents the i-th spreading code sequence in the spreading code sequence library, It represents the estimated signal desynchronization time of the kth user.

6. The method for determining system parameters of a CDMA communication system according to claim 5, characterized in that: The corresponding spread spectrum code sequence is obtained according to the desynchronization time of the user corresponding to the signal power value determined in step S12, and then the spread spectrum code sequence of the user is removed from the spread spectrum sequence library to obtain an updated spread spectrum code sequence library.

7. The method for determining system parameters of a CDMA communication system according to claim 1, characterized in that: In step S21, before calculating the signal bit error rate and signal-to-noise ratio at the second calibration reference plane and the fourth calibration reference plane, the signals measured at the first calibration reference plane and the second calibration reference plane are phase aligned, and the two aligned measurement signals are demodulated respectively to obtain a transmitted signal sequence and a received signal sequence.

8. The method for determining system parameters of a CDMA communication system according to claim 7, characterized in that: In step S23, the transmission signal fed back by the CDMA signal system is adjusted to be stable.

9. The method for determining system parameters of a CDMA communication system according to claim 5, characterized in that: In the step S11, the despread signal is normalized according to its maximum value.

10. The method for determining system parameters of a CDMA communication system according to claim 3, characterized in that: The network message is any one of a system broadcast SI message, a radio resource control RRC message and a downlink control message DCI.

Images