CN101997794B - Method and device for reducing mutual interference of multiple carriers - Google Patents
Method and device for reducing mutual interference of multiple carriers Download PDFInfo
- Publication number
- CN101997794B CN101997794B CN200910165242.5A CN200910165242A CN101997794B CN 101997794 B CN101997794 B CN 101997794B CN 200910165242 A CN200910165242 A CN 200910165242A CN 101997794 B CN101997794 B CN 101997794B
- Authority
- CN
- China
- Prior art keywords
- signal
- modulated signal
- phase
- carrier
- modulation
- 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.)
- Expired - Fee Related
Links
- 239000000969 carrier Substances 0.000 title claims abstract description 56
- 238000000034 method Methods 0.000 title claims abstract description 27
- 238000001228 spectrum Methods 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 14
- 230000008569 process Effects 0.000 description 8
- 230000005540 biological transmission Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 239000002131 composite material Substances 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 238000005457 optimization Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2626—Arrangements specific to the transmitter only
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Noise Elimination (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
The invention discloses a method for reducing mutual interference of multiple carriers, comprising the following steps: adjusting the phase of the modulated signal; and judging whether the baseband signal can be correctly demodulated, if not, continuously adjusting the phase of the modulated signal, and if so, taking the current modulated signal as the output signal. The invention simultaneously discloses a device for reducing mutual interference of the multiple carriers. The invention especially obviously improves the performance under the condition of adjacent configuration of multiple carriers, ensures that multiple carriers can simultaneously work in the same wireless signal coverage area and greatly improves the frequency spectrum utilization ratio.
Description
Technical Field
The present invention relates to a processing technique for multi-carrier mutual interference in a communication system, and more particularly, to a method and an apparatus for reducing multi-carrier mutual interference.
Background
At present, a wireless communication system can support a multi-carrier working mode, and the multi-carrier mode refers to a composite wave in which transmission and reception are carried out by a plurality of single carriers. For example, for an 800MHz CDMA2000lx communication system, the bandwidth of a single carrier is 1.23MHz, and the center frequency of adjacent carriers is spaced by 1.23MHz, when a plurality of carriers, for example, three carriers are adjacently configured, three single carriers with a bandwidth of 1.23MHz jointly form a composite wave occupying about 3.69MHz, and the center frequencies of the three carriers can be set to 871.11MHz, 872.34MHz, and 873.57MHz (or other frequencies). Fig. 1 is a schematic diagram of carrier interference occurring in three adjacent carriers in a frequency domain in a Code Division Multiple Access (CDMA) system, as shown in fig. 1, a frequency point of a first carrier in the diagram is 871.11MHz, a frequency point of a second carrier is 872.34MHz, and a frequency point of a third carrier is 873.57 MHz. In the multi-carrier mode, part of information of one carrier is aliased into adjacent carriers, that is, mutual interference among multiple carriers occurs, and it is particularly obvious when the carriers are configured adjacently. It can be seen from fig. 1 that the two shaded areas are aliasing areas of the carriers, that is, part of information of the first carrier is aliased into the second carrier, and part of information in the second carrier is aliased into the first carrier. A similar situation occurs for the second carrier and the third carrier. The information of one carrier is aliased into the information of the other carrier, and the part of the information becomes interference to influence the quality of the signal. Due to the existence of such interference, it is likely that the signals will not be demodulated correctly at the receiving end, and therefore, the mutual interference among such multiple carriers must be reduced, and the influence of such interference on the EV-DO signals in the CDMA system is particularly prominent. Of course, similar multi-carrier interference problems exist in systems such as WCDMA and TD-SCDMA.
In CDMA, WCDMA, TD-SCDMA, etc. systems, in order to ensure the quality of communication when in the multi-carrier mode of operation, the effect of mutual interference between the multiple carriers must be reduced. At present, no solution for multi-carrier interference in wireless communication systems exists in the industry.
Disclosure of Invention
In view of the above, the main objective of the present invention is to provide a method and an apparatus for reducing multi-carrier mutual interference, which can significantly reduce multi-carrier mutual interference of adjacent carrier frequencies.
In order to achieve the purpose, the technical scheme of the invention is realized as follows:
a method for reducing multi-carrier mutual interference, comprising:
adjusting the phase of the modulated signal; and
and judging whether the baseband signal can be correctly demodulated from the modulated signal, continuously adjusting the phase of the modulated signal when the baseband signal cannot be correctly demodulated, and taking the current modulated signal as an output signal when the baseband signal can be correctly demodulated.
Preferably, the phase of the modulated signal is adjusted, specifically: the phases of the modulated signals of the carriers are adjusted simultaneously.
Preferably, the phase of the modulated signal is adjusted, specifically: the modulated signals of each carrier are adjusted in sequence.
Preferably, when the modulation mode of the modulation signal is cascade modulation, the phase of the corresponding modulated signal is adjusted step by step from the modulation signal corresponding to the first-stage modulation until the baseband signal can be correctly demodulated from the modulated signal output by the last-stage modulation, and the modulated signal determined by each-stage modulation is used as the output signal.
Preferably, the phase of the modulated signal includes a carrier frequency of the modulated signal and an initial phase of the modulated signal.
Preferably, the adjusting the phase of the modulated signal is adjusting an initial phase of the modulated signal.
An apparatus for reducing multi-carrier mutual interference, comprising:
an adjusting unit for adjusting the phase of the modulated signal;
a demodulation unit, configured to demodulate the modulated signal;
the judging unit is used for judging whether the demodulation unit can correctly demodulate the baseband signal or not, triggering the adjusting unit to continuously adjust the phase of the modulated signal when the demodulation unit cannot correctly demodulate the baseband signal, and triggering the determining unit when the demodulation unit can correctly demodulate the baseband signal; and
and the determining unit is used for taking the current modulated signal as the modulated signal of the baseband signal.
Preferably, the adjusting unit simultaneously adjusts the phases of the modulated signals of the respective carriers.
Preferably, the adjusting unit sequentially adjusts the modulated signals of the carriers.
Preferably, when the modulation mode of the modulation signal is cascade modulation, starting from the modulation signal corresponding to the first-stage modulation, the adjusting unit adjusts the phase of the corresponding modulated signal step by step until the determining unit determines that the modulated signal output by the last stage can correctly demodulate the baseband signal, and the determining unit takes the modulated signal determined by each stage of modulation as the output signal.
Preferably, the phase of the modulated signal includes a carrier frequency of the modulated signal and an initial phase of the modulated signal.
Preferably, the adjusting unit adjusts an initial phase of the modulated signal.
Through the technical scheme, the invention realizes the following beneficial effects: the problem of mutual interference of multi-carrier signals in a wireless communication system can be well solved, and particularly the mutual interference between multi-carrier EV-DO signals in a CDMA system can be well solved. The performance improvement is particularly obvious in the case of multi-carrier adjacent configuration. Therefore, multiple carriers can work simultaneously in the same wireless signal coverage area, the frequency spectrum utilization rate is greatly improved, the flexibility of wireless planning is improved, the service capacity, the transmission rate and the service quality of a cell are improved, and the user experience is improved.
Drawings
FIG. 1 is a schematic diagram of carrier interference occurring in three carriers adjacent in the frequency domain in a CDMA system;
FIG. 2 is a diagram illustrating a single carrier modulation scheme in a wireless communication system;
FIG. 3 is a flow chart of a method for reducing multi-carrier mutual interference according to the present invention;
FIG. 4 is a schematic diagram of a parameter selection device according to the present invention;
FIG. 5 is a schematic diagram of a modulation signal adjusting apparatus according to the present invention;
fig. 6 is a schematic structural diagram of an interference reduction processing apparatus for carrier multi-level modulation according to the present invention;
fig. 7 is a schematic diagram of the structure of the apparatus for reducing multi-carrier mutual interference according to the present invention.
Detailed Description
The basic idea of the invention is: in a multi-carrier system, especially between adjacent multi-carriers in the frequency domain, mutual interference exists between the carriers. The invention controls the interference among the multiple carriers to be at the level of the effective signal in the modulation signal which can be correctly demodulated by adjusting the phase of the modulated signal of each carrier. Because the phase of the modulated signal is related to the carrier frequency and the initial phase of the carrier, and the carrier frequency of the carrier is basically planned by a communication system and belongs to non-adjustable parameters, the invention mainly reduces the interference between the multiple carriers by adjusting the initial phase of the modulated signal. The scheme of the invention is simple and practical to implement.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings by way of examples.
The transmission signal in modern wireless communication systems is transmitted by modulating information onto a modulated signal, which may be generated by an NCO (numerically controlled oscillator) or analog oscillator. The modulation process may be performed by various types of modulators, such as a real modulator, a complex modulator, or a quadrature modulator.
There are many parameters that reflect the characteristics of the modulated signal, two of which are frequency and phase. For example, the modulated signal c (t) can be expressed as: c (t) × a (t) × cos (2 π ft + θ) + j × a (t) × sin (2 π ft + θ). Where a (t) is amplitude, which is a variable related to time t and the baseband signal, f is carrier frequency, θ is the initial phase of the modulated signal, and (2 π ft + θ) is the phase of the modulated signal, which is a function of frequency f, time t, and initial phase θ, and is referred to as W (t, f, θ) in the present invention. In case of real modulation, only the real part of c (t) needs to be used.
In the conventional multi-carrier wireless communication system, only the frequency of the modulated signal is specified, and the purpose of reducing the inter-carrier interference is not achieved by specifically specifying the phase W of the modulated signal.
The phase W of the modulated signal is a function of frequency f, time t and initial phase theta, where t is the variation at a moment, and represents the characteristics of the signal, and is uncontrollable. f and theta are two controlled variables, either or both of which can be varied to achieve the purpose of adjusting the phase W of the modulated signal. In a wireless communication system, strict requirements are placed on the position of a transmitted carrier, so that the offset range of f is relatively narrow and the flexibility is weak, and the initial phase theta has a larger adjustment range and flexibility. The technical scheme of the invention is provided aiming at the characteristic.
This is further elucidated below by means of the drawing.
Fig. 2 is a schematic diagram of a single carrier modulation scheme in a wireless communication system, and as shown in fig. 2, the diagram includes two components, namely, a modulator 200 and a modulated signal generator 201. The modulator 200 is used to modulate an input signal x onto a modulated signal to obtain an output signal y, and the modulator 200 is a real modulator, a complex debugger, or a quadrature modulator, which are commonly used in a wireless communication system. The modulated signal generator 201 completes the generation of the modulated signal according to the input parameters. Only two input parameters are shown in the figure, a frequency input parameter f and a phase output parameter theta. The invention just adjusts the initial phase of the output signal y to achieve the purpose of reducing the interference among the carriers.
Fig. 3 is a flow chart of the method for reducing multi-carrier mutual interference according to the present invention, as shown in fig. 3, in step 301, input parameters of the parameter selecting device are set, and these parameters may include information parameters representing input signals (modulation signals or baseband signals). In step 302, the output signal (modulated signal) of the communication system is demodulated, so as to determine whether the baseband signal can be correctly demodulated as a basis for selecting the modulated signal. In step 304, it is determined whether the current modulated signal (output signal) meets the requirement based on the signal demodulation result obtained in step 302. In step 303, according to the demodulation result (when the baseband signal cannot be demodulated correctly), the initial phase of the next group of modulated signals is calculated according to the optimization algorithm, and is used as the new initial phase of each modulated signal. Steps 301, 302, 303 and 304 are repeated until an initial phase of a set of modulated signals is found so that the output signal can correctly demodulate the baseband signal. In step 305, the final initial phase is fixed and used as a set of modulated signals for the initial phase for a particular configuration.
Fig. 4 is a schematic diagram of the parameter selection apparatus according to the present invention, and as shown in fig. 4, the parameter selection apparatus of the present invention is composed of a signal extraction hardware and a phase selection software group. The signal extraction hardware may be specially designed circuits or may be specialized or general purpose instruments. The phase selection software may be software running in the CPU or software running in the programmable logic device or both, and the software may also be solidified and run in the form of hardware. Several input parameters required by the parameter selection device of the present invention when operating include: the type parameter n of the input signal, the signal number m of the input signal, and the position information k of the input signal. In actual use, only part or all of the input parameters can be used according to different systems or carrier conditions. The output parameter of the parameter selection device of the invention comprises an initial phase parameter selection result indicating signal of the modulated signal. The result indicating signal indicates an operating state, an end state or an operating state of the parameter selecting means. The parameter selection device of the present invention operates in the parameter selection mode of fig. 3, and can be used either before or during system operation. The parameter selection device of the invention is mainly used for generating the initial phase of each modulated signal and outputting the initial phase to each modulated signal, so that the initial phase of each modulated signal is output by taking the initial phase value output by the parameter selection device as the initial phase.
Fig. 5 is a schematic diagram of the structure of the present invention for adjusting the modulated signal by using the parameter selecting device, and as shown in fig. 5, the modulator group can be various types of modulators used in the wireless communication system, and its function is to perform multi-carrier modulation. The modulator group has two input signals, one is an input carrier signal, i.e., a modulation signal X1... Xm, and the other is a modulated signal 1.. m output by the modulated signal generator group. The combiner is used for combining the modulated m single carriers. The coupler is used for feeding back the output signal to the parameter selection device of the invention, and the output signal is used as an input parameter of the parameter selection device, and the parameter selection device of the invention selects the initial phase parameter according to a certain optimization algorithm together with other input parameters. And finally, setting the selected initial phase into each modulated signal. The function of the parameter selection means is the same as that of the parameter selection means shown in fig. 4. It should be noted that the present invention further includes a demodulator (not shown in the figure) for demodulating the modulated signal, the output modulated signal can be multiplexed and input to the demodulator, and the demodulation result of the demodulator is input to the parameter selection device of the present invention as a basis for whether to continuously adjust the initial phase of the modulated signal. The existing demodulator can be selected as the demodulator.
The following takes a three-carrier CDMA system as an example, and further explains the essence of the technical solution of the present invention by combining the method shown in fig. 3.
Fig. 3 is a flowchart of a method for reducing multi-carrier mutual interference according to the present invention, and as shown in fig. 3, the method for reducing multi-carrier mutual interference according to the present invention includes the following steps:
step 301: and setting the input parameters. The input parameters include relevant parameters representing the input signal. For example: the type of input carrier, in this example a CDMA 1X signal; the number of input carriers, in this example three carriers; inputting carrier position information, in this example 871.11MHz, 872.34MHz, 873.57MHz set in adjacent configuration; the initial phase parameter of the modulated signal is input, which in this case is obtained by a function of a random series generator, and the generator seeds are all set to 0 at the first start. Three initial values of carrier phase obtained by seed 0 are used as input parameters.
The invention demodulates the baseband signal in the modulated signal by setting the demodulation device, compares the baseband signal with the baseband signal which is configured in advance, if the baseband signal is the same as the modulated signal, the interference between the modulated signals is considered to meet the communication requirement, otherwise, the initial phase value of each modulated signal is continuously adjusted until the baseband signal can be correctly demodulated. The demodulation means may be implemented by hardware or software, and may be any existing demodulator or software implemented by a demodulation algorithm.
Step 302: and demodulating the baseband signal in the modulated signal. The signal demodulation process is the inverse process of signal modulation, that is, a channel of the modulated signal is determined through channel estimation and the like, and then the baseband signal is demodulated.
Step 303: the comparison result between the baseband signal demodulated in step 302 and the baseband signal configured in advance is used as the basis for selecting the phase of the modulated signal. If the demodulated baseband signal is the same as the preconfigured baseband signal, the phase adjustment process is exited, and step 305 is entered, otherwise, the process proceeds to step 304: the step amount (adjustment amount) is adjusted, and the process returns to step 301 to further adjust the initial phase of the modulated signal.
The algorithm for adjusting the initial phase of the modulated signal is a continuous cycle process, and the cycle cannot be exited until the demodulated baseband signal meets the requirement. The initial phase adjustment process of the present invention is explained in detail below.
Firstly, according to the frequency parameter of the modulated signal, the number from large to small is given in turn. As in this example, the number corresponding to-1.23 MHz is 1, the number corresponding to 0MHz is 2, and the number corresponding to 1.23MHz is 3; the level of the modulated signal phase setting priority is determined according to the number of the modulated signal. If the configuration is adjacent, the lowest-numbered priority is the lowest, the highest-numbered priority is the next highest, and the priorities of other numbers are arranged from large to small according to the size order of the numbers. If the carrier wave is in non-adjacent configuration, the modulated signal number is the priority, and the larger the priority, the higher the priority. After the setting is finished, an array with priority level and modulated signal number corresponding to each other and arranged from high to low is obtained. This example is for the case where the carrier frequencies of the carriers are consecutive, so the priorities corresponding to the modulated signals of each number are: number 1 corresponds to 1, number 2 corresponds to 3, and number 3 corresponds to 2. The larger the priority number, the higher the priority.
When the initial phase is adjusted, the step amount (adjustment amount) of each adjustment needs to be set, the coarse adjustment step amount set by the invention is 20 degrees, and the step amount is gradually reduced when the requirement cannot be met until the proper initial phase is determined.
The example of the step amount being 20 ° illustrates how the initial phase adjustment of the carrier wave is realized by the present invention. It is noted that the initial phase change of the carriers 1, 2, 3, respectively (generally starting with an initial phase of 0 °) is not exactly the same as the initial phase change of the three carriers, the phase between the three carriers cannot be exactly the same each time the initial phase of the carriers is adjusted, and if the initial phase of the three carriers is always the same, it is equivalent to that the initial phase of the three carriers is always 0 °, the interference between the three carriers will always be the same, and such phase adjustment is not meaningful. The present invention determines the case where the interference between each phase value (increment by integer multiple of step amount) corresponding to each carrier and each phase value (increment by integer multiple of step amount) corresponding to another carrier is minimum, and uses each carrier (modulated signal) with the minimum interference as a modulated signal of a baseband signal.
As described above, the change value of the initial phase of each carrier can be realized by the aforementioned parameter selection device, and it is sufficient to set a corresponding carrier increase/decrease flag (increment by integer multiple of the aforementioned step amount) for each carrier according to the set procedure, so as to determine the interference between all the initial phase values between each carrier.
If the step size is 20 °, and the baseband signal of each carrier cannot be correctly demodulated at the same time, the step size is adjusted to, for example, 10 °, and the interference between carriers (whether each carrier can demodulate the baseband signal or not) when various initial phases occur between carriers is determined again in the above manner, and each modulated signal can correctly demodulate the modulated signal of the baseband signal as an output signal. If the modulated signal of the baseband signal of each carrier cannot be determined at 20 °, the initial phase of each carrier is adjusted in the above manner by further adjusting the step amount, for example, to 5 ° or 1 °, and the modulated signal of the baseband signal can be correctly demodulated by each carrier.
It should be noted that the initial phases of the carriers may be adjusted simultaneously, that is, the initial phases of the carriers are changed simultaneously (the initial phases of the carriers are not the same at the same time), so as to determine that each carrier can correctly demodulate the modulated signal of the baseband signal. The initial phase of each carrier may also be adjusted in sequence, that is, the initial phase of one or more carriers is changed to make the initial phase of at least one of the carriers unchanged, so as to determine that each carrier can correctly demodulate the modulated signal of the baseband signal. The manner in which the modulated signal is determined is the same regardless of the manner in which the initial phase is adjusted.
It should be noted that the present invention is also applicable to the case of adjusting more than three carriers, specifically, the step amounts of initial phase adjustment of the carriers are respectively set according to the above-mentioned manner, and interference conditions of various initial phases (with the integer multiple of the step amount as increment) on each carrier are determined according to the set step amounts until each carrier is determined to be capable of correctly demodulating the modulated signal of the baseband signal as the output signal of each carrier.
Step 305: and solidifying the initial phase of the carrier, namely determining the modulated signal of the currently determined initial phase value as an output signal.
Fig. 6 is a schematic structural diagram of the interference reduction processing apparatus for multi-level carrier modulation according to the present invention, and as shown in fig. 6, the interference reduction processing apparatus is applied to n-level modulation of m carriers. The modulator group, modulated signal generator group, combiner and coupler in the figure have exactly the same functions as those of the respective devices shown in fig. 5, and each stage of modulator group is used for modulating the corresponding modulation signal onto the modulated signal. The initial phase of the modulated signal of one or more stages can be selectively adjusted during the multi-stage modulation. The present invention explains adjustment of an initial phase of a modulated signal in multi-stage modulation. On the whole, the implementation means of the initial phase adjustment of the modulated signal during multi-stage modulation is completely the same as that of the initial phase adjustment of the signal after single-stage modulation, the difference is that whether the baseband signal can be correctly demodulated from the modulated signal finally output is judged to determine whether the adjustment is finished during multi-stage modulation, and after the baseband signal can be correctly demodulated from the modulated signal finally output, the modulated signal determined at each stage is used as the output signal of each stage. The present invention also includes a demodulator (not shown in the figure) for demodulating the modulated signal output from the last stage, the modulated signal output from the last stage can be multiplexed and input into the corresponding demodulator, the demodulation result of the demodulator is input into the parameter selection device of the present invention, and is used as the basis for continuously adjusting the initial phase of the modulated signal. The existing demodulator can be selected as the demodulator.
When the modulation mode of the modulation signal is cascade modulation, the initial phase of the corresponding modulated signal is adjusted step by step from the modulation signal corresponding to the first-stage modulation, the adjustment mode is basically the same as the mode shown in the foregoing fig. 3, and only the judgment standard is different, and until the modulated signal output by the last stage can correctly demodulate the baseband signal, the modulated signal determined by each stage of modulation is used as the output signal of each stage.
The technical scheme disclosed by the invention is also suitable for the mixed configuration of carrier EV-DO signals and carrier 1X signals in different types of multi-carriers in a multi-carrier working mode, such as a CDMA system.
For the interference problem between carriers in different communication systems, the initial phase adjustment step amounts of the carriers are still set according to the above-mentioned manner, and when each modulated signal is in various phases (with the integral multiple of the step amount as increment), whether each modulated signal can correctly demodulate a baseband signal or not is determined, and each modulated signal can correctly demodulate the modulated signal of the baseband signal as an output signal. The initial phase adjustment mode between different communication systems is not different from the initial phase of the carrier in the same system, and the standard is that each carrier can correctly demodulate a baseband signal.
The technical scheme of the invention is also suitable for wireless communication systems of other systems, such as a Wideband Code Division Multiple Access (WCDMA) system and a Time Division Synchronous Code Division Multiple Access (TD-SCDMA) system.
Fig. 7 is a schematic diagram of a structure of an apparatus for reducing multi-carrier mutual interference according to the present invention, as shown in fig. 7, the apparatus for reducing multi-carrier mutual interference according to the present invention includes an adjusting unit 70, a demodulating unit 71, a determining unit 72, and a determining unit 73, wherein the adjusting unit 70 is configured to adjust a phase of a modulated signal; the demodulation unit 71 is configured to demodulate the modulated signal; the judging unit 72 is configured to judge whether the demodulation unit 70 can correctly demodulate the baseband signal, and when the demodulation unit 70 cannot correctly demodulate the baseband signal, trigger the adjusting unit 70 to continue adjusting the phase of the modulated signal, and when the demodulation unit can correctly demodulate the baseband signal, trigger the determining unit 73; the determination unit 73 is configured to use the current modulated signal as an output signal. The adjusting unit 70 simultaneously adjusts the phases of the modulated signals of the respective carriers. The adjusting section 70 sequentially adjusts the modulated signals of the respective carriers. The phase of the modulated signal comprises the carrier frequency of the modulated signal and the initial phase of the modulated signal. The adjusting unit 70 adjusts the initial phase of the modulated signal.
When the modulation mode of the modulation signal is cascade modulation, the adjusting unit 70 adjusts the phase of the corresponding modulated signal step by step from the modulation signal corresponding to the first-stage modulation until the determining unit 72 determines that the modulated signal output from the last stage can correctly demodulate the baseband signal, and the determining unit 73 takes the modulated signal determined by each stage of modulation as an output signal.
It should be understood by those skilled in the art that the apparatus for reducing multi-carrier mutual interference shown in fig. 7 of the present invention is designed to implement the foregoing method for reducing multi-carrier mutual interference, and the implementation functions of each processing unit in the apparatus shown in fig. 7 can be understood by referring to the related description in the foregoing method for reducing multi-carrier mutual interference, and the functions of each unit can be implemented by a program running on a processor and can also be implemented by corresponding logic circuits.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.
Claims (8)
1. A method for reducing multi-carrier mutual interference, comprising:
adjusting the phase of the modulated signal; and
judging whether the baseband signal can be correctly demodulated from the modulated signal, continuing to adjust the phase of the modulated signal when the baseband signal cannot be correctly demodulated, and taking the current modulated signal as an output signal when the baseband signal can be correctly demodulated; wherein,
an initial value of the phase of the modulated signal is obtained by setting a generator seed to 0;
and when the modulation mode of the modulation signal is cascade modulation, the phase of the corresponding modulated signal is adjusted step by step from the modulation signal corresponding to the first-stage modulation until the baseband signal can be correctly demodulated from the modulated signal output by the last stage, and the modulated signal determined by each-stage modulation is taken as an output signal.
2. The method according to claim 1, wherein adjusting the phase of the modulated signal comprises: the phases of the modulated signals of the carriers are adjusted simultaneously.
3. The method according to claim 1, wherein adjusting the phase of the modulated signal comprises: the modulated signals of each carrier are adjusted in sequence.
4. The method of claim 1, wherein the adjusting the phase of the modulated signal is adjusting an initial phase of the modulated signal.
5. An apparatus for reducing multi-carrier mutual interference, comprising:
an adjusting unit for adjusting the phase of the modulated signal;
a demodulation unit, configured to demodulate the modulated signal;
the judging unit is used for judging whether the demodulation unit can correctly demodulate the baseband signal or not, triggering the adjusting unit to continuously adjust the phase of the modulated signal when the demodulation unit cannot correctly demodulate the baseband signal, and triggering the determining unit when the demodulation unit can correctly demodulate the baseband signal; and
a determining unit, configured to use a current modulated signal as a modulated signal of the baseband signal;
when the modulation mode of the modulation signal is cascade modulation, starting from the modulation signal corresponding to the first-stage modulation, the adjusting unit adjusts the phase of the corresponding modulated signal step by step until the judging unit determines that the modulated signal output by the last stage can correctly demodulate the baseband signal, and the determining unit takes the modulated signal determined by each stage of modulation as an output signal.
6. The apparatus of claim 5, wherein the adjusting unit simultaneously adjusts the phase of the modulated signals of each carrier.
7. The apparatus of claim 5, wherein the adjustment unit sequentially adjusts the modulated signals of each carrier.
8. The apparatus of claim 5, wherein the adjusting unit adjusts an initial phase of the modulated signal.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910165242.5A CN101997794B (en) | 2009-08-08 | 2009-08-08 | Method and device for reducing mutual interference of multiple carriers |
| PCT/CN2009/075911 WO2011017885A1 (en) | 2009-08-08 | 2009-12-23 | Method and apparatus for reducing mutual interference of multi-carrier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910165242.5A CN101997794B (en) | 2009-08-08 | 2009-08-08 | Method and device for reducing mutual interference of multiple carriers |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101997794A CN101997794A (en) | 2011-03-30 |
| CN101997794B true CN101997794B (en) | 2015-01-28 |
Family
ID=43585874
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200910165242.5A Expired - Fee Related CN101997794B (en) | 2009-08-08 | 2009-08-08 | Method and device for reducing mutual interference of multiple carriers |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN101997794B (en) |
| WO (1) | WO2011017885A1 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1296684A (en) * | 1998-02-12 | 2001-05-23 | 金吉斯通讯公司 | Multiple access method and system |
| CN1514555A (en) * | 2002-12-31 | 2004-07-21 | �����ʩ���عɷݹ�˾ | Method of self eliminating interference between self adaptive carriers and receiving and transmitting machine |
| JP2005192000A (en) * | 2003-12-26 | 2005-07-14 | Toshiba Corp | Multicarrier communication system, and transmitter, receiver, transmission method, and reception method used for same system |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7200188B2 (en) * | 2003-01-27 | 2007-04-03 | Analog Devices, Inc. | Method and apparatus for frequency offset compensation |
| EP1881629A1 (en) * | 2005-05-30 | 2008-01-23 | Matsushita Electric Industrial Co., Ltd. | Wireless communication base station apparatus and wireless communication method in multicarrier communication |
| JP4958565B2 (en) * | 2006-01-06 | 2012-06-20 | パナソニック株式会社 | Wireless communication device |
| CN100576768C (en) * | 2007-02-14 | 2009-12-30 | 哈尔滨工业大学 | The compensation method of Doppler frequency shift in the MPSK mobile communication system |
-
2009
- 2009-08-08 CN CN200910165242.5A patent/CN101997794B/en not_active Expired - Fee Related
- 2009-12-23 WO PCT/CN2009/075911 patent/WO2011017885A1/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1296684A (en) * | 1998-02-12 | 2001-05-23 | 金吉斯通讯公司 | Multiple access method and system |
| CN1514555A (en) * | 2002-12-31 | 2004-07-21 | �����ʩ���عɷݹ�˾ | Method of self eliminating interference between self adaptive carriers and receiving and transmitting machine |
| JP2005192000A (en) * | 2003-12-26 | 2005-07-14 | Toshiba Corp | Multicarrier communication system, and transmitter, receiver, transmission method, and reception method used for same system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101997794A (en) | 2011-03-30 |
| WO2011017885A1 (en) | 2011-02-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7986966B2 (en) | Wireless communication device and signal detection circuit | |
| US8929352B2 (en) | Method and apparatus for multi-carrier frequency division multiplexing transmission | |
| KR101341305B1 (en) | Improved pilot allocation in multi-carrier systems with frequency notching | |
| US5903614A (en) | Communication method and receiving apparatus | |
| US20040047285A1 (en) | Sub-banded ultra-wideband communications system | |
| CN1538650B (en) | Multicarrier signal wave removing device and method | |
| US20230254194A1 (en) | Communication device and method for radio frequency communication | |
| RU2608758C2 (en) | Base station and method and device for returning signal | |
| JP2003069523A (en) | Ofdm communication device | |
| CN101997794B (en) | Method and device for reducing mutual interference of multiple carriers | |
| CN101997795B (en) | Method and device for reducing mutual interference of multiple carriers | |
| CN106413006A (en) | OFDM communication method and system with uniform subband overlapping | |
| EP2458744B1 (en) | Method and apparatus for reducing mutual interference of multi-carrier | |
| Vijayakumar et al. | Reconfigurable filter bank multicarrier modulation for cognitive radio spectrum sharing-a SDR implementation | |
| CN103201974A (en) | Communication apparatus and communication method | |
| CN101998595B (en) | Method and device for reducing mutual interference of multiple carriers | |
| EP3417546A1 (en) | Receiver circuit and methods | |
| CN101998592B (en) | Method and device for reducing mutual interference of multiple carriers | |
| EP4354979A1 (en) | Client device and network node device | |
| CN101998593B (en) | Method and device for reducing mutual interference of multiple carriers | |
| WO2011017887A1 (en) | Method and device for reducing mutual interference between multi-carriers | |
| WO2009107042A1 (en) | Frequency generation for an ultrawide band radio |
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 | ||
| ASS | Succession or assignment of patent right |
Owner name: SHANGHAI ZHONGXING SOFTWARE CO., LTD. Free format text: FORMER OWNER: ZTE CORPORATION Effective date: 20150210 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| COR | Change of bibliographic data |
Free format text: CORRECT: ADDRESS; FROM: 518057 SHENZHEN, GUANGDONG PROVINCE TO: 201203 PUDONG NEW AREA, SHANGHAI |
|
| TR01 | Transfer of patent right |
Effective date of registration: 20150210 Address after: 201203 No. 889 blue wave road, Shanghai, Pudong New Area Patentee after: Shanghai Zhongxing Software Co., Ltd. Address before: 518057 Nanshan District Guangdong high tech Industrial Park, South Road, science and technology, ZTE building, Ministry of Justice Patentee before: ZTE Corporation |
|
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20150128 Termination date: 20190808 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |