CN103856233B - Mobile terminal and signal processing method, baseband chip, radio frequency chip - Google Patents
Mobile terminal and signal processing method, baseband chip, radio frequency chip Download PDFInfo
- Publication number
- CN103856233B CN103856233B CN201210521020.4A CN201210521020A CN103856233B CN 103856233 B CN103856233 B CN 103856233B CN 201210521020 A CN201210521020 A CN 201210521020A CN 103856233 B CN103856233 B CN 103856233B
- Authority
- CN
- China
- Prior art keywords
- signal
- module
- communication
- radio frequency
- sampling
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000003672 processing method Methods 0.000 title claims abstract description 15
- 238000004891 communication Methods 0.000 claims abstract description 109
- 238000005070 sampling Methods 0.000 claims abstract description 99
- 239000013078 crystal Substances 0.000 claims abstract description 55
- 238000000034 method Methods 0.000 claims abstract description 15
- 230000010355 oscillation Effects 0.000 claims description 46
- 238000012545 processing Methods 0.000 claims description 32
- 230000015572 biosynthetic process Effects 0.000 claims description 4
- 230000001360 synchronised effect Effects 0.000 claims description 4
- 238000003786 synthesis reaction Methods 0.000 claims description 4
- 230000002194 synthesizing effect Effects 0.000 claims description 3
- 230000007423 decrease Effects 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 8
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
Landscapes
- Transceivers (AREA)
Abstract
The invention discloses a kind of mobile terminal and signal processing method, baseband chip, radio frequency chip, wherein said mobile terminal comprises baseband chip and radio frequency chip.In radio frequency chip, the radio-frequency module of all communication patterns shares the oscillator signal of a crystal oscillator generation.In baseband chip, by the sampling module corresponding with each radio-frequency module, sampling is carried out to the output signal obtained and obtain sampled signal, and according to the frequency shift (FS) between this output signal and corresponding base station signal, phase compensation is carried out to obtain signal of communication to respective sampled signal by compensating module, thus realize the Frequency Synchronization of each signal of communication and corresponding base station signal.The technical program decreases cost and the power consumption of radio frequency chip and baseband chip in multi-module mobile terminal, also eliminates complicated clock handoff procedure.
Description
Technical Field
The invention relates to the technical field of mobile communication, in particular to a mobile terminal and a signal processing method, a baseband chip and a radio frequency chip thereof.
Background
The radio frequency chip and the baseband chip are important components of the mobile terminal, and the mobile terminal receives and transmits data and signals through the radio frequency chip and processes the received data and signals or the data and signals to be transmitted through the baseband chip. Fig. 1 is a schematic structural diagram of a radio frequency chip and a baseband chip of a conventional single radio frequency mobile terminal. Referring to fig. 1, the rf chip 11 includes: crystal oscillator 111, frequency synthesizer 112, mixer 113, low pass filter 114, and antenna 115. The baseband chip 12 includes: a communication module 121 and a common module 122. Wherein the communication module 121 comprises a first phase-locked loop 1211 and a clock distribution structure 1212; the common module 122 includes a second phase locked loop 1221 and a clock distribution structure 1222. In the baseband chip 12, the common module 122 is a circuit module independent of a communication mode of the mobile terminal.
The working principle of the radio frequency chip 11 and the baseband chip 12 is as follows: in the case where the communication module 121 or the common module 122 in the baseband chip 12 needs a reference clock, the crystal oscillator 111 enters an operating state to generate an oscillation signal, and the baseband chip 12 may use the oscillation signal as the reference clock. Specifically, in the baseband chip 12, the first phase-locked loop 1211 of the communication module 121 and the second phase-locked loop 1221 of the common module 122 respectively use the oscillation signal as their respective reference clocks. Further, reference clocks of different frequencies are obtained by respective clock distribution structures (i.e., the clock distribution structure 1212 in the communication module 121 and the clock distribution structure 1222 in the common module 122) with reference to the reference clock for use by other modules within the baseband chip 12.
When the mobile terminal communicates with the base station, since there may be a frequency offset between the mobile terminal and the base station, the frequency of the oscillation signal generated by the crystal oscillator 111 needs to be fine-tuned to keep the mobile terminal and the base station frequency synchronized. The specific process is as follows: with continued reference to fig. 1, an oscillation signal is generated by the crystal oscillator 111, the oscillation signal is frequency synthesized by the frequency synthesizer 112 to generate a local carrier, a received base station signal is mixed with the local carrier by the mixer 113 to obtain a mixed signal, and the mixed signal is filtered by the low pass filter 114 to remove out-of-band signals, thereby obtaining I/Q signals (i.e., in-phase and quadrature signals). Then, the baseband chip 12 performs a series of operations on the I/Q signal to obtain a frequency offset that needs to be adjusted, and converts the frequency offset into an Automatic Frequency Control (AFC) voltage. Finally, the frequency of the oscillation signal generated by the crystal oscillator 111 is finely adjusted by the automatic frequency control voltage, thereby correcting the frequency offset.
For a multi-mode and multi-pass mobile terminal, since it is necessary to support simultaneous communication in multiple communication modes, the baseband chip needs to maintain synchronization with the frequencies of the base stations in the multiple communication modes at the same time to ensure the communication quality of the corresponding communication modes. In the existing method, a plurality of crystal oscillators are used in a radio frequency chip, one crystal oscillator is used in each communication mode, a baseband chip respectively calculates I/Q signals output by the radio frequency chip in different communication modes to obtain corresponding automatic control voltages, and then each automatic control voltage respectively finely adjusts the corresponding crystal oscillator to correct respective frequency offset.
Fig. 2 is a schematic structural diagram of a radio frequency chip and a baseband chip of a conventional multi-mode and multi-pass mobile terminal. Referring to fig. 2, the rf chip 21 includes a plurality of rf modules, such as the rf module 211, the rf modules 212 and …, and the rf module 21n, and the structure of each rf module is the same as that of the rf chip 11 in fig. 1, and will not be described in detail here. The baseband chip 22 includes a plurality of communication modules, such as a communication module 221, communication modules 222, …, and a communication module 22n, and the structure in each communication module is the same as that of the communication module 121 in the baseband chip 12 in fig. 1, and will not be described in detail here. Each communication module uses the oscillation signal generated by the crystal oscillator in the corresponding rf module as a reference clock, and uses the oscillation signal generated by the crystal oscillator in the rf module 211 as a reference clock (e.g., reference clock 1 shown in fig. 2) of the communication module 221.
When the mobile terminal needs to support simultaneous communication in multiple communication modes, the rf modules corresponding to the communication modes respectively generate oscillation signals, each rf module respectively outputs corresponding I/Q signals (I/Q signal 1, I/Q signal 2, …, I/Q signal n shown in fig. 2) to the baseband chip 22, and the corresponding communication modules in the baseband chip 22 respectively perform operations on each I/Q signal to obtain frequency offsets between the baseband chip 22 and the base stations of each communication mode, and convert the frequency offsets into automatic frequency control voltages (automatic frequency control voltage 1, automatic frequency control voltage 2, …, automatic frequency control voltage n shown in fig. 2) to respectively fine-tune crystal oscillators in the corresponding rf modules to correct the respective frequency offsets. In practice, it is not only very costly to provide multiple crystal oscillators in a radio frequency chip, but also much power is consumed in the case where multiple crystal oscillators are simultaneously operated.
On the other hand, with continued reference to fig. 2, a common module 222 is further included in the baseband chip 22, and the structure of the common module 222 is the same as that of the common module 122 in the baseband chip 12 in fig. 1, and will not be described in detail here. Since the common module 222 is suitable for circuit modules independent of each communication mode, the reference clock of the common module 222 can be selected from the reference clocks of any one communication mode, and as shown in fig. 2, a multiplexer 223 can be arranged to receive the reference clocks of each communication mode and select one as the reference clock of the common module 222. Such a design architecture creates a problem: assuming that the rf module 211 and the rf module 212 are currently in operation, the reference clock of the common module 222 is derived from the oscillation signal generated by the crystal oscillator of the rf module 211 (i.e., reference clock 1). If the user needs to turn off the rf module 211, the reference clock 1 generated by the rf module 211 is also turned off, and the reference clock of the common module 222 cannot be immediately switched to the oscillation signal (i.e., the reference clock 2) generated by the crystal oscillator of the rf module 212, and the reference clock 2 can be selected only when the common module 222 enters the deep sleep state and then wakes up again, so that the clock switching of the baseband chip is very complicated in the multi-mode and multi-pass state.
For more technical solutions for frequency synchronization between a mobile terminal and a base station, reference may be made to U.S. patent application publication No. US6922406B2 entitled "method for synchronizing base stations".
Disclosure of Invention
The invention solves the problems of reducing the cost and the power consumption of a radio frequency chip and a baseband chip in the multi-mode mobile terminal and avoiding a complex clock switching process.
In order to solve the above problem, an embodiment of the present invention provides a mobile terminal, including a baseband chip and a radio frequency chip, where the radio frequency chip includes a first radio frequency module and at least one second radio frequency module, each radio frequency module includes a signal processing module, the first radio frequency module further includes a crystal oscillator for generating an oscillation signal, and all the second radio frequency modules share the crystal oscillator; the signal processing module is used for processing the oscillation signal and a received base station signal to obtain an output signal;
the baseband chip comprises a plurality of sampling modules and compensation modules which respectively correspond to the radio frequency modules; the sampling module is used for sampling the output signal from the corresponding radio frequency module according to a preset sampling period to obtain a sampling signal; the compensation module comprises an automatic frequency control module and a phase compensator; wherein the AFC module is configured to determine a frequency offset between the output signal from the corresponding RF module and the base station signal; the phase compensator is configured to perform phase compensation on the sampling signal by using the frequency offset to obtain a communication signal.
Optionally, the phase compensator is configured to implement the following equation:
Optionally, the signal processing module includes an antenna, a frequency synthesizer, a mixer, and a low pass filter; wherein, the antenna is used for receiving base station signals; the frequency synthesizer is used for carrying out frequency synthesis on the oscillation signal so as to generate a local carrier; the mixer is used for mixing the received base station signal with the local carrier to generate a mixed signal; the low pass filter is configured to remove out-of-band signals in the mixed signal to obtain the output signal.
Optionally, the baseband chip further includes a communication module and a phase-locked loop circuit respectively corresponding to each radio frequency module; the phase-locked loop circuit receives the oscillation signal and outputs a reference clock of the communication module, and the communication module is used for processing the communication signal from the corresponding compensation module.
Optionally, the baseband chip further includes a common module; the oscillating signal serves as a reference clock for the common module.
Optionally, the baseband chip further includes a control module, and the control module is configured to control the start-up and the shutdown of the crystal oscillator.
Optionally, each rf module corresponds to a different communication mode, and the preset sampling period is set based on the communication mode corresponding to the rf module.
Based on the mobile terminal, an embodiment of the present invention further provides a signal processing method for a mobile terminal, including: receiving base station signals in at least one communication mode; processing each base station signal and an oscillation signal generated by a crystal oscillator to obtain a corresponding output signal; determining a frequency offset between each of the output signals and the base station signal; sampling each output signal according to a preset sampling period to obtain a corresponding sampling signal; performing phase compensation on each of the sampled signals using the frequency offset to obtain a corresponding communication signal.
Optionally, the phase compensation for each of the sampling signals by using the frequency offset to obtain the corresponding communication signal is implemented by using the following formula:
Optionally, the processing the base station signal and an oscillation signal generated by a crystal oscillator to obtain an output signal includes: frequency synthesizing the oscillation signal to generate a local carrier; mixing the received base station signal with the local carrier to generate a mixed signal; removing out-of-band signals in the mixed signal to obtain the output signal.
Optionally, the oscillation signal is converted into a reference clock of a communication module by a phase-locked loop circuit, and the communication module is configured to process the communication signal obtained in the corresponding communication mode.
Optionally, the preset sampling period is set based on different communication modes.
Based on the mobile terminal, an embodiment of the present invention further provides a radio frequency chip, including a first radio frequency module and at least one second radio frequency module, where each radio frequency module includes a signal processing module, the first radio frequency module further includes a crystal oscillator for generating an oscillation signal, and all the second radio frequency modules share the crystal oscillator; the signal processing module is used for processing the oscillation signal and the received base station signal to obtain an output signal.
Based on the mobile terminal, the embodiment of the invention also provides a baseband chip, which comprises a plurality of sampling modules and compensation modules, wherein the sampling modules and the compensation modules respectively correspond to the radio frequency modules in the radio frequency chip; the sampling module is used for sampling the output signal from the corresponding radio frequency module according to a preset sampling period to obtain a sampling signal; the compensation module comprises an automatic frequency control module and a phase compensator; wherein the AFC module is configured to determine a frequency offset between the output signal from the corresponding RF module and the base station signal; the phase compensator is configured to perform phase compensation on the sampling signal by using the frequency offset to obtain a communication signal.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects:
no matter how many communication modes are supported by the mobile terminal, in the radio frequency chip, the radio frequency modules of all the communication modes share the oscillation signal generated by the crystal oscillator. In the baseband chip, sampling is carried out on the obtained output signals through sampling modules corresponding to the radio frequency modules to obtain sampling signals, and a compensation module carries out phase compensation on the respective sampling signals according to frequency offset between the output signals and corresponding base station signals to obtain communication signals, so that frequency synchronization of the communication signals and the corresponding base station signals is realized. Because only one crystal oscillator is used in the radio frequency chip, the chip cost is reduced, and the chip power consumption is saved.
Furthermore, because only one crystal oscillator is arranged in the radio frequency chip, and the oscillation signal generated by the crystal oscillator is used as a reference clock for the common module and each communication module in the baseband chip, the complex clock switching process possibly required by the common module in the prior art is avoided, and the signal processing efficiency of the mobile terminal is improved.
Drawings
Fig. 1 is a schematic structural diagram of a radio frequency chip and a baseband chip of a conventional single radio frequency mobile terminal;
fig. 2 is a schematic structural diagram of a radio frequency chip and a baseband chip of a conventional multi-mode and multi-pass mobile terminal;
FIG. 3 is a schematic structural diagram of a radio frequency chip and a baseband chip of a multi-mode and multi-pass mobile terminal according to the present invention;
fig. 4 is a flowchart illustrating a signal processing method of a mobile terminal according to an embodiment of the present invention.
Detailed Description
Aiming at the problems in the prior art, the inventor provides a mobile terminal, a signal processing method thereof, a baseband chip and a radio frequency chip through research, so that the cost and the power consumption of the radio frequency chip and the baseband chip in the multi-mode mobile terminal are reduced, and a complex clock switching process is avoided.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.
In the following description, specific details are set forth in order to provide a thorough understanding of the present invention. The invention can be implemented in a number of ways different from those described herein and similar generalizations can be made by those skilled in the art without departing from the spirit of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.
Fig. 3 is a schematic structural diagram of a radio frequency chip and a baseband chip of the multi-mode and multi-pass mobile terminal according to the present invention. Referring to fig. 3, first, the internal structures of the rf chip 31 and the baseband chip 32 are described in detail, respectively.
The rf chip 31 includes a plurality of rf modules, such as the rf module 311, the rf modules 312 and …, and the rf module 31n shown in fig. 3, where n is greater than or equal to 2. The specific number of the radio frequency modules can be determined according to the number of the communication modes supported by the mobile terminal.
Unlike the prior art, in the present embodiment, the rf chip 31 includes two rf modules, one of which includes a crystal oscillator and a signal processing module; another radio frequency module includes a signal processing module but does not include a crystal oscillator. Specifically, with continued reference to fig. 3, in the rf chip 31, the rf module 311 includes a crystal oscillator 3111 and a signal processing module, and the remaining n-1 rf modules include the signal processing module but do not include the crystal oscillator. In this embodiment, the signal processing module includes an antenna, a frequency synthesizer, a mixer, and a low pass filter. For example, the radio frequency module 311 includes a frequency synthesizer 3112, a mixer 3113, a low pass filter 3114, and an antenna 3115; the rf module 312 includes a frequency synthesizer 3122, a mixer 3123, a low pass filter 3124, and an antenna 3125; the rf module 31n includes a frequency synthesizer 31n2, a mixer 31n3, a low pass filter 31n4, and an antenna 31n 5.
The baseband chip 32 includes a plurality of sampling modules and compensation modules corresponding to the radio frequency modules, respectively. Specifically, with continued reference to fig. 3, the baseband chip 32 includes a sampling module 3211 and a compensation module 321 corresponding to the radio frequency module 311, a sampling module 3221 and compensation modules 322 and … corresponding to the radio frequency module 312, and a sampling module 32n1 and a compensation module 32n corresponding to the radio frequency module 31 n. Each sampling module is used for sampling the output signal from the corresponding radio frequency module according to a preset sampling period to obtain a sampling signal. Each compensation module respectively performs phase compensation on a sampling signal obtained after the output signal of the corresponding radio frequency module is sampled by the sampling module to obtain a communication signal.
Each compensation module includes a phase compensator and an automatic frequency control module. For example, the compensation module 321 includes a phase compensator 3212 and an automatic frequency control module 3213; the compensation module 322 includes a phase compensator 3222 and an automatic frequency control module 3223; the compensation module 32n includes a phase compensator 32n2 and an automatic frequency control module 32n 3.
The baseband chip 32 further includes a communication module and a phase-locked loop circuit respectively corresponding to the radio frequency modules. Specifically, with continued reference to fig. 3, the baseband chip 32 includes a communication module 3214 and a phase-locked loop circuit 3215 corresponding to the radio frequency module 311, a communication module 3224 and phase-locked loop circuits 3225 and … corresponding to the radio frequency module 312, and a communication module 32n4 and a phase-locked loop circuit 32n5 corresponding to the radio frequency module 31 n. Each phase-locked loop circuit uses the oscillation signal generated by the crystal oscillator 3111 as a reference clock of a corresponding communication module, and each communication module is configured to process the communication signal from a corresponding compensation module.
The baseband chip 32 further includes a common module 323, and the common module 323 is a circuit module independent of various communication modes, such as a separate application processor in an intelligent mobile terminal. Unlike the prior art, in the embodiment, since there is only one crystal oscillator 3111 in the rf chip 31, the common module 323 usually uses the oscillation signal generated by the crystal oscillator 3111 as the reference clock. The baseband chip 32 further includes a control module 324, and the control module 324 is configured to control the start-up and shut-down of the crystal oscillator 3111. In practical applications, when any communication module in the baseband chip 32 or the common module 323 needs a reference clock, the control module 324 controls the crystal oscillator 3111 to start oscillation to generate an oscillation signal as the reference clock of the communication module or the common module. When no circuit module in the baseband chip 32 needs a reference clock, the control module 324 controls the crystal oscillator 3111 to be turned off.
The following describes in detail the working principle of the rf chip 31 and the baseband chip 32 when the mobile terminal communicates with the base station simultaneously in multiple communication modes (i.e. multiple modes and multiple channels) according to the schematic structural diagrams of the rf chip and the baseband chip shown in fig. 3. It should be noted that this embodiment is described based on an example that the mobile terminal maintains frequency synchronization between the downlink signal and the respective base station signals during processing the downlink signal in multiple communication modes.
The control module 324 controls the crystal oscillator 3111 to start oscillating to generate an oscillation signal. Since the rf chip 31 has only one crystal oscillator 3111, in the case of multi-mode and multi-pass, each rf module shares the crystal oscillator 3111, that is, the signal processing module in each rf module processes the oscillation signal generated by the crystal oscillator 3111 and the received base station signal to obtain the output signal thereof.
In this embodiment, the signal processing module in each rf module performs frequency synthesis on the oscillation signal through a frequency synthesizer to generate a local carrier, where the local carrier generally includes a sine wave signal and a cosine wave signal, and the phases of the two signals are different by 90 degrees. A base station signal corresponding to the communication mode is received through the antenna. Then, the received base station signal is mixed with the local carrier by a mixer to generate a mixed signal, that is, the base station signal is mixed with a sine wave signal and a cosine wave signal respectively to generate two corresponding mixed signals. Then, an out-of-band signal in the mixed signal is removed by a low-pass filter to obtain the output signal, wherein the out-of-band signal refers to a part of the signal outside the band-pass range of the low-pass filter. Since the mixed signal includes both the mixed signal of the sine wave signal and the base station signal and the mixed signal of the cosine wave signal and the base station signal, the output signal is an in-phase and quadrature signal (i.e., I/Q signal). It should be noted that the signal processing module is not limited to the antenna, the frequency synthesizer, the mixer and the low pass filter described above, and in practical applications, a corresponding processing module may be added according to the signal processing requirement, which does not affect the essence of the present invention and is not described in detail herein.
Since the frequencies of the base stations in the communication modes are different in most cases, there is a frequency offset between the output signal obtained by each rf module and the base station signal in each communication mode. Unlike the prior art, each rf module does not use a crystal oscillator, and therefore, the frequency offset between the output signal of each rf module and the base station signal cannot be corrected by fine tuning the crystal oscillator. Therefore, the inventors considered that, in the baseband chip, frequency synchronization with the corresponding base station signal is achieved by performing phase compensation on the output signals obtained by the respective radio frequency modules.
In this embodiment, the output signals output by the radio frequency modules are sampled by the corresponding sampling modules in the baseband chip 32 to obtain sampling signals, and then the sampling signals are phase compensated by the corresponding compensation modules. For example, with reference to fig. 3, the output signal 1 output by the radio frequency module 311 is sampled by the sampling module 3211 to obtain a sampled signal, and then the phase compensation is performed on the sampled signal by the compensation module 321; the output signal 2 output by the radio frequency module 312 is sampled by the sampling module 3221 to obtain a sampling signal, and then the phase compensation is performed on the sampling signal by the compensation module 322; the output signal n output by the rf module 31n is sampled by the sampling module 32n1 to obtain a sampled signal, and then phase compensation is performed by the compensation module 32 n.
Specifically, the output signal output by each rf module is an analog signal, and a sampling module (here, an analog-to-digital sampling module) corresponding to each rf module samples the output signal according to a preset sampling period to obtain a sampling signal, where the sampling signal is a digital signal. In this embodiment, a specific period value of the preset sampling period is not limited.
Each compensation module determines a frequency offset between the output signal from the corresponding radio frequency module and the base station signal through an automatic frequency control module. Those skilled in the art will appreciate that in each rf module, the mixer essentially converts two different frequencies (i.e., the base station signal and the local carrier of the communication mode corresponding to that rf module) into a mixed signal having a new oscillation frequency associated with both, the new oscillation frequency being the difference between the two different frequencies, which is the frequency offset between the output signal and the base station signal. However, the frequency offset cannot be determined in each rf module, and needs to be determined by the afc module in the compensation module corresponding to each rf module. In practical applications, the automatic frequency control module may obtain the frequency offset through internal operations.
And the phase compensator in each compensation module performs phase compensation on the sampling signal according to the frequency offset to obtain a communication signal.
For example, let r (n) be a sampling signal without frequency offset, Δ f be a frequency difference between a local carrier (obtained by frequency synthesis of an oscillation signal generated by a crystal oscillator) and a base station signal (i.e., the frequency offset), n be a sampling count value, and t be a preset sampling periodsThe initial phase deviation between the oscillation signal generated by the crystal oscillator and the base station signal is phiinitThe sampled signal R' (n) of the output signal output by any rf module after sampling can be expressed as:
wherein, the sampling signal without frequency deviation is R (n) corresponding to the base station signal of each communication mode according to the respective preset sampling period tsAnd carrying out the sampled sampling signal. The frequency difference between the local carrier and the base station signal is Δ f, which is equivalent to the frequency offset between the output signal from the corresponding radio frequency module and the base station signal that needs to be determined by the automatic frequency control module.
Further, the phase compensator in each compensation module can compensate phi =2 pi × Δ f × n × t for the sampled signal R' (n) sampled by the sampling modulesThe phase deviation of (a), that is, the communication signal R "(n) obtained after the phase compensation is performed on each sampling signal R' (n) subjected to the sampling processing by the sampling module by the respective phase compensator, is:
it can be seen that the communication signal R ″ (n) output by each compensation module and the sampling signal without frequency offset R (n) have only a fixed phase difference ΦinitThereby realizingThe respective communication signals R "(n) are frequency synchronized with the base station signals in the respective communication modes.
On the other hand, in the baseband chip 32, the common module 323 and the respective communication modules (such as the communication module 3214, the communication modules 3224 and …, and the communication module 32n4 shown in fig. 3) use the oscillation signal generated by the crystal oscillator 3111 as a reference clock, and thus a complicated clock switching process is eliminated as compared with the prior art.
It should be noted that the schematic structural diagrams of the radio frequency chip and the baseband chip provided in this embodiment are mainly applied to a multi-mode and multi-pass mobile terminal. For a single-mode single-pass (i.e., single radio frequency) mobile terminal, the structures of the radio frequency chip and the baseband chip provided in this embodiment may also be adopted, that is, the output signal output by the radio frequency chip is sampled first to obtain a sampling signal, and then the sampling signal is subjected to phase compensation to achieve frequency synchronization with the base station signal. However, since only one crystal oscillator is needed in a single rf chip, it is preferable to synchronize the frequency of the base station signal by directly fine-tuning the frequency of the crystal oscillator, that is, it is preferable to use the rf chip and the baseband chip shown in fig. 1 in a single rf mobile terminal.
Based on the structure of the radio frequency chip and the baseband chip of the multi-mode and multi-pass mobile terminal, the embodiment of the invention also provides a signal processing method of the mobile terminal. Fig. 4 is a schematic flow chart of an embodiment of a signal processing method of a mobile terminal according to the present invention. Referring to fig. 4, the signal processing method includes:
step S1: receiving base station signals in at least one communication mode;
step S2: processing each base station signal and an oscillation signal generated by a crystal oscillator to obtain a corresponding output signal;
step S3: determining a frequency offset between each of the output signals and the base station signal;
step S4: sampling each output signal according to a preset sampling period to obtain a corresponding sampling signal;
step S5: performing phase compensation on each of the sampled signals using the frequency offset to obtain a corresponding communication signal.
In a specific embodiment, the step S2 specifically includes: frequency synthesizing the oscillation signal to generate a local carrier; mixing the received base station signal with the local carrier to generate a mixed signal; removing out-of-band signals in the mixed signal to obtain the output signal. The preset sampling period in the step S4 is set based on different communication modes.
The present embodiment is implemented based on the structures of the rf chip and the baseband chip of the multi-mode and multi-pass mobile terminal shown in fig. 3. Referring to fig. 3 in combination, in the baseband chip 32, each communication signal obtained by processing by the communication module corresponding to the communication mode, the reference clock of each communication module is obtained by converting the oscillation signal generated by the crystal oscillator by each corresponding phase-locked loop circuit.
The specific execution process of each step in this embodiment may refer to the embodiment described in fig. 3, and is not described herein again.
Although the present invention has been described with reference to the preferred embodiments, it is not intended to limit the present invention, and those skilled in the art can make variations and modifications of the present invention without departing from the spirit and scope of the present invention by using the methods and technical contents disclosed above.
Claims (12)
1. A mobile terminal comprises a baseband chip and a radio frequency chip, and is characterized in that,
the radio frequency chip comprises a first radio frequency module and at least one second radio frequency module, wherein each radio frequency module comprises a signal processing module, the first radio frequency module further comprises a crystal oscillator for generating an oscillation signal, and all the second radio frequency modules share the crystal oscillator; the signal processing module is used for processing the oscillation signal and a received base station signal to obtain an output signal;
the baseband chip comprises a plurality of sampling modules and compensation modules which respectively correspond to the radio frequency modules; the sampling module is used for sampling the output signal from the corresponding radio frequency module according to a preset sampling period to obtain a sampling signal; the compensation module comprises an automatic frequency control module and a phase compensator; wherein the AFC module is configured to determine a frequency offset between the output signal from the corresponding RF module and the base station signal; the phase compensator is configured to perform phase compensation on the sampling signal by using the frequency offset to obtain communication signals, and each communication signal obtained after the phase compensation is synchronized with a frequency of a corresponding base station signal.
2. The mobile terminal of claim 1, wherein the phase compensator is configured to implement the following equation:
wherein, R' (n) represents a sampling signal obtained by sampling the output signal from the corresponding radio frequency module according to a preset sampling period; r ″ (n) represents a communication signal obtained by phase-compensating each sampling signal R' (n) by a respective phase compensator; Δ f denotesThe frequency offset; n represents a sample count value; t is tsRepresenting a preset sampling period.
3. The mobile terminal of claim 1, wherein the signal processing module comprises an antenna, a frequency synthesizer, a mixer, and a low pass filter; wherein,
the antenna is used for receiving base station signals; the frequency synthesizer is used for carrying out frequency synthesis on the oscillation signal so as to generate a local carrier; the mixer is used for mixing the received base station signal with the local carrier to generate a mixed signal; the low pass filter is configured to remove out-of-band signals in the mixed signal to obtain the output signal.
4. The mobile terminal of claim 1, wherein the baseband chip further comprises a communication module and a phase-locked loop circuit respectively corresponding to the radio frequency modules; the phase-locked loop circuit takes the oscillation signal as a reference clock of the communication module, and the communication module is used for processing the communication signal from the corresponding compensation module.
5. The mobile terminal of claim 1, wherein the baseband chip further comprises a common module; the oscillating signal serves as a reference clock for the common module.
6. The mobile terminal of claim 1, wherein the baseband chip further comprises a control module configured to control the start-up and shut-down of the crystal oscillator.
7. The mobile terminal of claim 1, wherein each rf module corresponds to a different communication mode, and the preset sampling period is set based on the communication mode corresponding to the rf module.
8. A signal processing method of a mobile terminal, comprising:
receiving base station signals in at least one communication mode;
processing each base station signal and an oscillation signal generated by a crystal oscillator to obtain a corresponding output signal;
determining a frequency offset between each of the output signals and the base station signal;
sampling each output signal according to a preset sampling period to obtain a corresponding sampling signal;
and performing phase compensation on each sampling signal by using the frequency offset to obtain a corresponding communication signal, wherein each communication signal obtained after the phase compensation is synchronous with the frequency of a corresponding base station signal.
9. The signal processing method of claim 8, wherein the phase compensating each of the sampled signals by using the frequency offset to obtain the corresponding communication signal is implemented by using the following formula:
wherein R' (n) is in accordance withSampling the output signals from the corresponding radio frequency modules in a set sampling period to obtain sampling signals; r ″ (n) represents a communication signal obtained by phase-compensating each sampling signal R' (n) by a respective phase compensator; Δ f represents the frequency offset; n represents a sample count value; t is tsRepresenting a preset sampling period.
10. The signal processing method of claim 8, wherein processing the base station signal and an oscillation signal generated by a crystal oscillator to obtain an output signal comprises:
frequency synthesizing the oscillation signal to generate a local carrier;
mixing the received base station signal with the local carrier to generate a mixed signal;
removing out-of-band signals in the mixed signal to obtain the output signal.
11. The signal processing method of claim 8, wherein the oscillating signal is converted into a reference clock of a communication module through a phase-locked loop circuit, and the communication module is configured to process the communication signal obtained in a corresponding communication mode.
12. The signal processing method of claim 8, wherein the preset sampling period is set based on different communication modes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210521020.4A CN103856233B (en) | 2012-12-07 | 2012-12-07 | Mobile terminal and signal processing method, baseband chip, radio frequency chip |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210521020.4A CN103856233B (en) | 2012-12-07 | 2012-12-07 | Mobile terminal and signal processing method, baseband chip, radio frequency chip |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103856233A CN103856233A (en) | 2014-06-11 |
| CN103856233B true CN103856233B (en) | 2016-04-06 |
Family
ID=50863493
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210521020.4A Active CN103856233B (en) | 2012-12-07 | 2012-12-07 | Mobile terminal and signal processing method, baseband chip, radio frequency chip |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN103856233B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106155178B (en) * | 2015-04-14 | 2019-05-31 | 深圳市中兴微电子技术有限公司 | A kind of multimode terminal and its automatic frequency control switching method |
| CN108362941B (en) * | 2018-03-29 | 2023-07-18 | 珠海迈科智能科技股份有限公司 | Equipment and method for testing frequency deviation of Tuner module crystal oscillator |
| CN113766697B (en) * | 2021-09-24 | 2024-05-03 | 华源智信半导体(深圳)有限公司 | LED backlight system, driving chip thereof and processing method of main control chip |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101369882A (en) * | 2007-08-17 | 2009-02-18 | 电子科技大学 | Frequency synchronization method based on pre-correction of sending terminal |
| EP2055003A2 (en) * | 2006-08-09 | 2009-05-06 | QUALCOMM Incorporated | Reference signal generation for multiple communication systems |
| CN102045082A (en) * | 2009-10-12 | 2011-05-04 | 展讯通信（上海）有限公司 | Control method of dual-standby terminal and AFC (automatic frequency control) loop of dual-standby terminal |
| CN203014803U (en) * | 2012-12-07 | 2013-06-19 | 展讯通信（上海）有限公司 | Mobile terminal, base-band chip and radio frequency chip |
-
2012
- 2012-12-07 CN CN201210521020.4A patent/CN103856233B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2055003A2 (en) * | 2006-08-09 | 2009-05-06 | QUALCOMM Incorporated | Reference signal generation for multiple communication systems |
| CN101369882A (en) * | 2007-08-17 | 2009-02-18 | 电子科技大学 | Frequency synchronization method based on pre-correction of sending terminal |
| CN102045082A (en) * | 2009-10-12 | 2011-05-04 | 展讯通信（上海）有限公司 | Control method of dual-standby terminal and AFC (automatic frequency control) loop of dual-standby terminal |
| CN203014803U (en) * | 2012-12-07 | 2013-06-19 | 展讯通信（上海）有限公司 | Mobile terminal, base-band chip and radio frequency chip |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103856233A (en) | 2014-06-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8331520B2 (en) | Phase-locked loop circuit and communication apparatus | |
| CN103856232B (en) | Mobile terminal and signal processing method, baseband chip, radio frequency chip | |
| US8660596B2 (en) | Electronic apparatus and associated frequency adjusting method | |
| CN105075110B (en) | The phase-detection of the local oscillator generator operated in a non-continuous manner and correction | |
| US7062240B2 (en) | Automatic frequency control processing in multi-channel receivers | |
| CN105191142B (en) | Local oscillator (LO) generator with multi-phase frequency divider and phaselocked loop | |
| US8599825B2 (en) | System clock synchronization apparatus and method for mobile communication system | |
| KR20030043959A (en) | Wideband fast-hopping receiver front-end and mixing method | |
| CN103856233B (en) | Mobile terminal and signal processing method, baseband chip, radio frequency chip | |
| JP2003018123A (en) | Ofdm receiver | |
| EP2202897B1 (en) | Technique for synchronizing network access modules in a mobile communication device | |
| CN203014803U (en) | Mobile terminal, base-band chip and radio frequency chip | |
| JP2010081247A (en) | Frequency synthesizer and radio transmitting apparatus | |
| KR100881790B1 (en) | Receiver and wireless communication apparatus | |
| US10356736B2 (en) | Circuit arrangement for clock synchronization | |
| RU2554542C2 (en) | Clocking circuit for wireless communication device | |
| CN116418361A (en) | Radio frequency transceiver chip and radio frequency transceiver device | |
| US20050136877A1 (en) | Frequency offset correction in transmitters and receivers having non-ideal synthesizer channel spacing | |
| EP2110973A2 (en) | Technique for synchronizing network access modules in a mobile communication device | |
| JP2013153242A (en) | Base station | |
| JP2007215039A (en) | Frequency synthesizer, communication device, and frequency synthesizing method | |
| KR100473606B1 (en) | Cdma receiving circuit | |
| CN116667847A (en) | Beidou radio frequency synthesizer, method, device, phase-locked loop and storage medium | |
| JP2018074201A (en) | Electronic apparatus | |
| JPH1132359A (en) | Pager |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |