Super-strong path selection processing device and method in WCDMA system
Technical Field
The invention relates to a third generation mobile communication system, in particular to a super strong path selection processing method and a device in the multi-path management of a Wideband Code Division Multiple Access (WCDMA).
Background
In WCDMA (wideband code division multiple access) systems, to combat multipath fading, a RAKE receiver is used to process the received signal, and for the RAKE receiver, if the result of channel estimation is simply assigned to the taps of the RAKE receiver, some of the taps are assigned estimates of pure noise, so that the result of channel estimation is usually channel-identified using multipath searching techniques to reduce the possibility of such assignment errors and improve the performance of the RAKE receiver. The multipath search function includes energy delay characteristic estimation and multipath allocation, the estimation of the energy delay characteristic is noisy due to the influence of thermal noise and interference, accurate estimation of the multipath is required, the multipath with sudden jump occurs in the multipath search, the multipath is not stable and can cause false alarm, in order to ensure the stability of the multipath search and reduce the false alarm, IIR filtering must be adopted for the amplitude delay spectrum (or power delay spectrum) of the late detection integral output, but if any multipath search structure adopts IIR filtering only, the strong path of the burst can be weakened after filtering and cannot be allocated correctly, and the result greatly affects the system performance under certain propagation environments (such as the extinguishing environment shown in FIG. 1). Therefore, the IIR filtering is performed while considering the detection of the super-strong path, and then a special filtering process is performed to ensure that the burst true path with strong energy is demodulated in time, and in order to save storage resources, a 1-order IIR filtering method is adopted. At present, the function of super-strong path judgment processing is mainly completed in software, so that hardware of a baseband processing system needs to send energy values on all phases of the search window width number of a search task and phase values of the energy values and the phase values to the software together, which puts high requirements on data transmission rate and transmission quantity of a software and hardware interface and increases design difficulty.
Therefore, how to correctly select and process the super-strong path in the multipath management process is to ensure the stability of multipath search and reduce false alarms, thereby improving the system performance and the like, which becomes a key point to be urgently solved.
Disclosure of Invention
The technical problem to be solved by the present invention is to provide a device and a method for selecting and processing a super-strong path in a WCDMA system, so as to solve the problems of correctly selecting and correctly processing a super-strong path in a multipath management process, ensuring the stability of multipath search, reducing false alarms, and improving system performance.
In order to solve the above problems, the present invention provides a device for selecting and processing a super strong path in a WCDMA system, which is applied to processing the super strong path existing in the ADP value of a task window width phase point in the multipath management of the WCDMA system, and is characterized in that the device comprises: a searcher and a super-strong processor; wherein,
the searcher generates a conjugate sequence corresponding to a scrambling code in antenna data according to parameters configured by a system task, performs spreading processing on the conjugate sequence by using a spreading code, matches the generated scrambling code sequence with the received antenna data sequence to generate data, accumulates the generated data according to the size of a spreading factor to obtain pilot symbol data, performs accumulation after de-signing the pilot symbol data according to coherent accumulation parameters, performs modulo operation on the obtained result to obtain the result of all coherent accumulation, and finally adds the results of each coherent accumulation according to noncoherent accumulation parameters to obtain an ADP value of a task window width phase point;
and the super-strong path processor receives the output of the searcher, calculates the minimum value and the average value of historical ADP values, and approximately deduces the historical ADP standard deviation from the minimum value and the average value, so as to deduce a super-strong threshold value, then judges whether the received ADP value of each phase point in the current task window width range is far greater than the historical ADP value, is greater than the super-strong path threshold value, and is greater than the ADP values of the phase points on the left side and the right side of the corresponding phase point at the same time, if the ADP value of a certain phase point meets the three conditions at the same time, the ADP value of the phase point is a super-strong path, filters the ADP value of the super-strong radial phase point and the ADP values of other phase points after the operation is finished, and then outputs the filtering result and the phase points.
The apparatus of the present invention is characterized in that the searcher comprises:
a code generator that stores and provides parameters for system task configuration;
a correlation operation module, which generates a conjugate sequence corresponding to the scrambling code in the antenna data according to the parameter of the system task configuration provided by the code generator, and uses the spreading code to perform spreading processing on the conjugate sequence, and multiplies the generated scrambling code sequence and the received antenna data sequence to generate data output;
a de-spread operation module for receiving the generated data output by the correlation operation module, accumulating according to the size of the spread spectrum factor and outputting pilot frequency symbol data;
a coherent accumulation operation module, which receives the pilot symbol data output by the de-spread operation module, carries out accumulation after de-signing the pilot symbol data according to coherent accumulation parameters, and simultaneously carries out modulo operation on the obtained result to obtain and output all coherent accumulation results;
the incoherent accumulation operation module is used for receiving the result output by the coherent accumulation operation module, adding and summing the results of coherent accumulation of each time according to incoherent accumulation parameters to obtain an ADP value of a phase point, and repeating the operation to finally obtain the ADP value of a task window width phase point;
the super strong path processor comprises:
a current ADP value storage module which receives and stores the ADP value of the task window width phase point output by the searcher;
the historical ADP value storage module is used for calculating the minimum value and the average value of the historical ADP values and approximately deducing the historical ADP standard deviation from the minimum value and the average value;
the super-strong path threshold calculation module is used for deducing a super-strong threshold value from historical ADP standard deviation;
a super-strong path judging module, which receives the ADP value of each phase point within the task window width range in the current ADP value storage module to judge whether the ADP value is far greater than the historical ADP value, whether the ADP value is greater than the super-strong path threshold value, whether the ADP value is greater than the ADP values of the phase points on the left and right sides of the corresponding phase point at the same time, and if the ADP value of a certain phase point meets the above three conditions at the same time, the ADP value of the phase point is a super-strong path;
and the filtering module is used for filtering the ADP value of the super-strong radial phase point and the ADP values of other phase points and then outputting a filtering result and the phase points.
The apparatus of the present invention, wherein the super strong path processor further comprises:
and the ADP judging module is used for judging whether the ADP value received by the current ADP value storage module is received for the first time or not, and if so, directly storing the ADP value into the historical ADP value storage module.
The apparatus of the present invention, wherein the super-strong path determining module determines whether the ADP values of the phase points on the left and right sides of the corresponding phase point are greater than the ADP value of the corresponding phase point at the same time, further includes:
if the current ADP value is the value of the first phase point reported by the task, judging whether the current ADP value is larger than the ADP value of the right phase point, and if the current ADP value is the value of the last phase point reported by the task, judging whether the current ADP value is larger than the ADP value of the left phase point.
The device comprises a filtering module, a phase point acquisition module and a phase point acquisition module, wherein the filtering module is used for filtering the ADP value of the super-strong radial phase point and the ADP values of other phase points by different filtering coefficients respectively, performing fixed-point processing on the filtering process, and then outputting the filtering result and the phase points thereof;
different filter coefficients are adopted in the filter module, the superstrong filtered coefficient is adopted for ADP values of superstrong-path phase points, and the normal IIR filter coefficient is adopted for ADP values of other phase points.
In order to solve the above problems, the present invention further provides a method for selecting and processing a super strong path in a WCDMA system, which is applied to processing the super strong path existing in the ADP value of a task window width phase point in the multipath management of the WCDMA system, and is characterized by comprising the following steps:
(1) generating a conjugate sequence corresponding to a scrambling code in antenna data according to parameters configured by a system task, performing addition and expansion processing on the conjugate sequence by using a spreading code, multiplying and matching the generated scrambling code sequence and the received antenna data sequence to generate data, accumulating the generated data according to the size of a spreading factor to obtain pilot symbol data, performing accumulation after de-signing the pilot symbol data according to coherent accumulation parameters, performing modulo operation on the obtained results to obtain all coherent accumulation results, adding and summing the coherent accumulation results of each time according to noncoherent accumulation parameters to obtain an ADP value of a phase point, and repeating the operation to obtain the ADP value of a task window width phase point;
(2) calculating the minimum value and the average value of historical ADP values, approximately deducing the historical ADP standard deviation from the minimum value and the average value, deducing a superstrong threshold value, judging whether the received ADP value of each phase point in the current task window width range is far larger than the historical ADP value, whether the received ADP value is larger than the superstrong diameter threshold value, whether the received ADP value of each phase point is simultaneously larger than the ADP values of the phase points on the left side and the right side of the corresponding phase point, if the ADP value of a certain phase point simultaneously meets the three conditions, the ADP value of the phase point is a superstrong diameter, filtering the ADP value of the superstrong diameter phase point and the ADP values of other phase points after the operation is finished, and then outputting a filtering result and the phase.
The method of the present invention, wherein the step (2) further comprises:
judging whether the ADP value obtained in the step (1) is received for the first time, if so, directly storing the ADP value into a historical ADP value storage module.
The method of the present invention, wherein whether the ADP values of the phase points on the left and right sides of the corresponding phase point are simultaneously greater than the ADP value in step (2), further includes:
if the current ADP value is the value of the first phase point reported by the task, judging whether the current ADP value is larger than the ADP value of the right phase point, and if the current ADP value is the value of the last phase point reported by the task, judging whether the current ADP value is larger than the ADP value of the left phase point.
The method of the present invention, wherein the step (2) of filtering the ADP value of the super strong radial phase point and the ADP values of other phase points, and then outputting the filtering result and the phase points thereof, includes:
respectively filtering the ADP value of the super-strong radial phase point and the ADP values of other phase points by adopting different filter coefficients, performing fixed-point processing on the filtering process, and then outputting the filtering result and the phase points thereof;
different filter coefficients are adopted, the super-strong-diameter filter coefficient is adopted for ADP values of super-strong-diameter phase points, and the normal IIR filter coefficient is adopted for ADP values of other phase points.
The device for processing the super-strong path considers that the super-strong path judgment processing function is realized through hardware, so that the hardware only needs to send the final searched path result to software, the data interaction amount between the hardware and the software is greatly reduced, and the data transmission amount and the design complexity are greatly reduced on the basis of not influencing the system performance. In addition, the device for selecting and processing the ultra-strong path is applied to the multi-path management of the WCDMA system, ADP of a task window width phase point samples each phase point twice, and ADP calculation is carried out, so that the ultra-strong path existing in ADP values with twice task window widths is processed.
Similarly, the invention also provides a method for processing the super-strong path, in particular to a super-strong path selection processing method in a WCDMA system, which applies the ADP minimum value, the average value and the standard deviation to dynamically calculate the super-strong path threshold in real time, overcomes the defect that the super-strong path threshold is difficult to select when a fixed threshold is used for selecting the super-strong path, can accurately distinguish the super-strong path from the common path and carry out different filtering processes, thereby ensuring the stability of multi-path search, reducing false alarms and ensuring the system performance; meanwhile, in order to overcome the problem that a large amount of data needs to be transmitted between hardware and software when an algorithm is realized in the software, the invention provides a structure realized based on a hardware FPGA (Field-Programmable Gate Array), a storage method combining a register set and an RAM is used in hardware design, the hardware is easy to realize, the consumed hardware resource is less, the working speed is high, the requirement that the design needs to work under high working frequency is well met, and the complexity of the hardware design is greatly reduced.
Drawings
FIG. 1 is a diagram illustrating the distribution of the diameter of a live and extinguished environment in the prior art of the present invention;
fig. 2 is a flowchart of a method for super strong path selection processing in a WCDMA system according to an embodiment of the present invention;
fig. 3 is a flowchart illustrating a step 202 in the super-strong path processing in the method for selecting and processing the super-strong path in the WCDMA system according to the embodiment of the present invention;
fig. 4 is a connection diagram of a specific structure of a searcher in a device with super strong path selection processing in a WCDMA system according to an embodiment of the present invention;
fig. 5 is a connection diagram of a detailed structure of a super-strong path processor in a device for selecting super-strong paths in a WCDMA system according to an embodiment of the present invention;
fig. 6 is a hardware structure diagram of an average value calculation in a historical ADP value module in the ultra-high-path processor according to the embodiment of the present invention;
fig. 7 is a hardware structure diagram for calculating a minimum value in the historical ADP value module in the ultra-high-diameter processor according to the embodiment of the present invention.
Detailed Description
In order to solve the drawbacks of the conventional technical solutions, the present invention further provides an apparatus and a method for selecting and processing a super-strong path in a WCDMA system according to the following embodiments, which are described in detail below, but not limited to the embodiments of the present invention.
The technical scheme of the method for selecting and processing the ultra-strong path in the WCDMA system comprises the following steps:
referring to fig. 2, a method for processing super-strong path in WCDMA system includes the following steps:
step 201, calculating an ADP value of a corresponding window width phase point of a task by using a searcher;
step 202, searching whether the super-strong path exists by using a super-strong path selection algorithm, if the super-strong path exists, filtering the super-strong path by using a special filtering coefficient, putting the filtered result into a candidate path result, and putting other ADP values into the candidate path result after normal filtering for subsequent processing.
The method described above, wherein step 201, specifically includes the following:
2011, the operation is to generate a conjugate sequence of the corresponding scrambling code in the antenna data according to the parameters configured by the system task, perform spreading processing on the conjugate sequence by using a spreading code (OVSF) same as the antenna data, and multiply the generated scrambling code sequence and the antenna data sequence;
step 2012, adding the result of step 2011 by the spreading factor;
step 2013, the operation is to add the pilot symbol data part of the de-spread result according to the coherent accumulation parameter, and to get the module of the result;
step 2014, adding the results of each coherent accumulation according to the incoherent accumulation parameters to obtain an ADP value;
the method described above, wherein step 202, specifically includes the following steps, as shown in fig. 3:
step 2021, calculating a minimum value, an average value and a standard deviation of the task reporting history ADP, wherein the value of the standard deviation is approximately generated by the minimum value and the average value of the ADP;
2022, calculating a superstrong diameter threshold value according to the value calculated in the step 2021;
step 2023, determining whether the ADP value of the current phase point is much larger than the historical ADP value;
step 2024, determining whether the ADP value of the current phase point is greater than the super-strong threshold value obtained in step 2022;
step 2025, determining whether the ADP value of the current phase point is greater than the ADP value of each phase point around the corresponding phase;
step 2026, if the conditions in steps 2023, 2024, and 2025 are met at the same time, the phase point has a super-strong path;
step 2027, filtering the ADP value corresponding to the super-strong radial phase point by using a special filter coefficient;
step 2028, performing IIR filtering on the ADP values corresponding to the other phase points by using a normal filter coefficient;
step 2029, then, the filtering result and the phase point thereof are output, and the filtered ADP value is stored in the candidate path result.
The method for processing the super-strong path in the WCDMA system provided by the embodiment of the invention applies the ADP minimum value, the average value and the standard deviation to dynamically calculate the super-strong path threshold in real time, overcomes the defect that the super-strong path threshold is difficult to select when a fixed threshold is used for selecting the super-strong path, can accurately distinguish the super-strong path from a common path and carry out different filtering processes, thereby ensuring the stability of multi-path search, reducing false alarms and ensuring the system performance; meanwhile, in order to overcome the problem that a large amount of data needs to be transmitted between hardware and software when an algorithm is realized in the software, the invention provides a structure realized on the basis of a hardware FPGA (field programmable gate array). A storage method combining a register set and an RAM (random access memory) is used in hardware design, the hardware is easy to realize, less hardware resource is consumed, the working speed is high, the requirement that the design needs to work under high working frequency is well met, and the complexity of the hardware design is greatly reduced.
The device for processing the super-strong path in the embodiment of the invention mainly comprises two parts: a searcher for calculating the current ADP value and a super-strong path processor.
As shown in fig. 4, the searcher includes:
a code generator 401 that stores and provides parameters for system task configuration;
a correlation operation module 402, which generates a conjugate sequence corresponding to the scrambling code in the antenna data according to the parameter of the system task configuration provided by the code generator, performs a spreading process on the conjugate sequence by using a spreading code (OVSF) identical to the antenna data, multiplies and matches the generated scrambling code sequence with the received antenna data sequence, and generates data output;
a despreading operation module 403, configured to receive the generated data output by the correlation operation module 402, accumulate the generated data according to the spreading factor, and output pilot symbol data;
a coherent accumulation operation module 404, configured to receive the pilot symbol data output by the parsing operation module 403, perform accumulation after de-signing the pilot symbol data according to coherent accumulation parameters, and perform modulo operation on an obtained result to obtain and output all coherent accumulation results;
and an incoherent accumulation operation module 405, which receives the result output by the coherent accumulation operation module 404, sums up the results of coherent accumulation of each time according to an incoherent accumulation parameter to obtain an ADP value of one phase point, and repeats the above module operations to finally obtain an ADP value of a task window width phase point.
As shown in fig. 5, the hardware functional structure block diagram of the super-large-diameter processor includes:
a current ADP value storage module 501, which receives and stores the ADP values of the task window width phase points output by the searcher;
a historical ADP value storage module 502 which calculates the minimum value and the average value of the historical ADP values and approximately deduces the historical ADP standard deviation from the minimum value and the average value;
a super-strong path threshold calculation module 503, which deduces a super-strong threshold value from historical ADP standard deviation;
a super strong path determining module 504, configured to receive the ADP value of each phase point within the task window width range in the current ADP value storing module 501, and determine whether the ADP value is far greater than the historical ADP value, whether the ADP value is greater than the super strong path threshold value, and whether the ADP value is greater than the ADP values of the phase points on the left and right sides of the corresponding phase point at the same time, where if the ADP value of a certain phase point meets the above three conditions at the same time, the ADP value of the phase point is the super strong path
The filtering module 505 is configured to filter the ADP value of the super-strong radial phase point and the ADP values of other phase points, and then output a filtering result and the phase points thereof;
an ADP determining module 506, configured to determine whether the ADP value received by the current ADP value storing module 501 is received for the first time, and if so, directly store the ADP value in the RAM in the historical ADP value storing module 502.
Specifically, the input of the super-strong path selection processing part is an ADP value of a current task, and because the selection processing processes of the super-strong path all need the participation of the current ADP and a historical ADP value, whether the input ADP value is reported for the first time is judged at the beginning of the algorithm, if so, the current ADP value is directly stored in a historical ADP storage RAM without passing through a super-strong path selection processing flow, if not, the super-strong path selection processing operation is started, and the minimum value and the average value of the historical ADP value are calculated at first;
wherein, the implementation process of the historical ADP average value as shown in FIG. 6 is to average the ADP values of all the histories in the phase range with the search window width, because of the limitation of hardware resources, firstly, division is carried out on ADP value of each phase point and window width, the result is processed in a fixed point mode, the number of bits of an accumulation unit is reduced, then accumulating and summing all the results after fixed point processing to obtain approximate historical ADP mean value, in the hardware implementation block diagram of fig. 5, according to the window width parameter configured by the task, each ADP value is sequentially divided by the window width parameter, the result is fixed-point processed, the accumulator completes the accumulation of the result, at the same time, the counter counts the counter, and stores the counting result, compares the counting result with the window width parameter, when the accumulation of all sample points in the window width range is finished, resetting the counter and outputting the historical ADP average value;
as shown in fig. 7, for the implementation process of selecting the historical ADP minimum value, since the number of the ADP values is fixed and the input of the ADP values is serial input, in hardware, we use a register set, a comparator and an and gate to implement the comparison of the ADP values in real time, so as to obtain the required minimum value.
As shown in fig. 3, the standard deviation of the historical ADP is approximately obtained from the obtained historical ADP minimum value and the historical ADP average value, and the super-strong-diameter threshold value is obtained. And the ADP value of each phase point in the window width range is judged according to the following conditions: judging whether the current ADP value is far larger than the historical ADP value; judging whether the current ADP value is larger than the super-strong diameter threshold value or not; judging whether the current ADP value is simultaneously larger than the ADP value of each phase point at the left and right of the corresponding phase (if the current ADP value is the value of the first phase point reported by the task, the value is judged whether to be larger than the ADP value of the right phase point, and if the current ADP value is the value of the last phase point reported by the task, the value is judged whether to be larger than the ADP value of the left phase point); if the ADP value of a certain phase point meets the three conditions, the phase point is judged to have a super-strong diameter, the filter filters the ADP value of the super-strong diameter phase point and the ADP values of other phase points by different filter coefficients after the operation is finished (the ADP value of the super-strong diameter phase point adopts the super-strong filter coefficient, the ADP values of other phase points adopt the normal IIR filter coefficient), the filtering process is subjected to fixed-point processing, and then the filtering result and the phase points thereof are stored in a candidate diameter storage RAM.
The scheme can be completely applied to the selection processing scheme of the ultra-strong path, and is realized in an FPGA hardware mode, so that real-time processing is realized.
The present invention provides a method and a device for selecting and processing super strong path in a WCDMA system, which can ensure the stability of multi-path search and reduce false alarm, thereby improving the system performance, and simultaneously, the realization on hardware is simple and easy, the consumption of hardware resources is little, and the working speed is high.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore intended that all such changes and modifications as fall within the true spirit and scope of the invention be considered as within the following claims.