WO2011017885A1

WO2011017885A1 - Method and apparatus for reducing mutual interference of multi-carrier

Info

Publication number: WO2011017885A1
Application number: PCT/CN2009/075911
Authority: WO
Inventors: 李凡龙; 毕文仲; 劳锦明
Original assignee: 中兴通讯股份有限公司
Priority date: 2009-08-08
Filing date: 2009-12-23
Publication date: 2011-02-17
Also published as: CN101997794B; CN101997794A

Abstract

A method for reducing mutual interference of multi-carrier includes: adjusting the phase of at least one modulated signal; judging whether baseband signals can be all demodulated correctly from each modulated signal, adjusting the phase of at least one modulated signal when the modulated signals which can not be demodulated correctly are present, until the baseband signals can be all demodulated correctly from each modulated signal; setting the current modulated signals as the output signals when the baseband signals can be all demodulated correctly. The present invention also discloses an apparatus for reducing mutual interference of multi-carrier. The present invention can improve the performance obviously under the circumstance of arranging the multi-carrier adjacent to each other, and makes the multi-carrier be operated simultaneously in the same radio signal coverage area, therefore greatly improving the frequency spectrum utilization ratio.

Description

Method and device for reducing multi-carrier mutual interference

The present invention relates to a processing technique for multi-carrier mutual interference in a communication system, and more particularly to a method and apparatus for reducing multi-carrier mutual interference. Background technique

At present, the wireless communication system can support multi-carrier operation mode. In the multi-carrier operation mode, the carrier signals transmitted and received by the relevant network elements are combined signals of multiple single carriers. For example, for a CDMA2000 lx communication system in the 800 MHz band, the bandwidth of a single carrier is 1.23 MHz, the center frequency interval of adjacent carriers is 1.23 MHz, and multiple carriers, such as three carriers adjacent to each other, are three single carriers of 1.23 MHz bandwidth. Together, they form a multiplexed wave with a bandwidth of about 3.69 MHz. The center frequencies of the three carriers can be set to 871.11 MHz, 872.34 MHz, and 873.57 MHz (other frequencies are also possible). FIG. 1 is a schematic diagram of carrier interference of three adjacent carriers in a frequency domain in a Code Division Multiple Access (CDMA) code system. As shown in FIG. 1, the frequency of the first carrier in the figure is 871.11 MHz, and second. The carrier frequency is 872.34 MHz, and the frequency of the third carrier is 873.57 MHz. In the multi-carrier mode, the phenomenon that part of the information of one carrier is aliased into the adjacent carrier occurs, that is, mutual interference between multiple carriers occurs, and the interference phenomenon is particularly obvious when the carrier is adjacently arranged. It can be seen from Fig. 1 that the two shaded areas are the aliasing areas of the carrier, that is, the partial information of the first carrier is aliased to the second carrier, and part of the information in the second carrier is aliased to the first In the carrier. A similar situation exists for the second carrier and the third carrier. When the information of another carrier is aliased in one carrier, the information will become an interference and affect the quality of the signal. Due to the existence of such interference, the receiver may not be able to properly demodulate the signal at the receiving end. This kind of interference is particularly significant for the EV-DO (Evolution-Data Optimized) signal in the CDMA system. Of course, in Wideband Code Division Multiple Access (WCDMA, Similar multi-carrier interference problems exist in systems such as Wideband Code Division Multiple Access and Time Division-Synchronous Code Division Multiple Access (TD-SCDMA).

In the multi-carrier wireless communication system, in order to ensure the quality of communication, especially in the multi-carrier EV-DO communication mode in the CDMA system, the influence of mutual interference between carriers must be reduced. There is currently no solution to multi-carrier mutual interference in multi-carrier EV-DO adjacent configurations in wireless communication systems, especially in CDMA systems. Summary of the invention

In view of the above, it is a primary object of the present invention to provide a method and apparatus for reducing multi-carrier mutual interference, which can significantly reduce multi-carrier mutual interference of adjacent carrier frequencies.

In order to achieve the above object, the technical solution of the present invention is achieved as follows:

A method for reducing multi-carrier mutual interference, comprising:

Adjusting the phase of at least one modulated signal;

Determining whether the baseband signal can be correctly demodulated from each modulated signal, and if there is a modulated signal that cannot be correctly demodulated, adjusting the phase of at least one of the modulated signals until after being modulated from each modulated signal The baseband signal can be correctly demodulated; when both are correctly demodulated, the current modulated signals are used as output signals.

Preferably, the adjusting the phase of the at least one modulated signal is specifically: adjusting the phase of the modulated signal of each carrier simultaneously.

Preferably, the adjusting the phase of the at least one modulated signal is specifically: sequentially adjusting the modulated signals of the carriers.

Preferably, when the modulation mode of the modulation signal is cascading modulation, the phase of the corresponding modulated signal is adjusted step by step from the modulation signal corresponding to the first-stage modulation until after the modulation of the final stage output. When the signal can correctly demodulate the baseband signal, each modulated signal determined by each level of modulation is used as an 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 to adjust an initial phase of the modulated signal.

A device for reducing mutual interference of multiple carriers, comprising an adjusting unit, a demodulating unit, a determining unit and a determining unit, wherein:

An adjusting unit, configured to adjust a phase of the at least one modulated signal;

a demodulation unit, configured to demodulate each modulated signal;

a determining unit, configured to determine whether the baseband signal can be correctly demodulated from each modulated signal, and if there is a modulated signal that cannot be correctly demodulated, triggering the adjusting unit to further adjust at least one modulated signal in the modulated signal Phase, until the baseband signal can be correctly demodulated from each modulated signal; when both can be correctly demodulated, the determining unit is triggered;

A determining unit is configured to use each of the current modulated signals as an output signal.

Preferably, the adjusting unit adjusts the phase of the modulated signal of each carrier simultaneously. Preferably, the adjusting unit sequentially adjusts the modulated signals of the carriers.

Preferably, when the modulation mode of the modulation signal is cascading modulation, starting from the modulation signal corresponding to the first-stage modulation, the adjustment unit adjusts the phase of the corresponding modulated signal step by step until the determining unit When it is determined that each of the modulated signals outputted by the last stage can correctly demodulate the baseband signal, the determining unit uses each modulated signal determined by each level of modulation as an 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 adjustment unit adjusts an initial phase of the modulated signal.

Through the above technical solutions, the present invention achieves the following beneficial effects: The mutual interference problem of multi-carrier signals in a wireless communication system can be better solved, especially for multi-carrier in a CDMA system Mutual interference between EV-DO signals. The performance improvement is especially noticeable in the case of multi-carrier adjacent configuration. In this way, the same wireless signal coverage area can have multiple carriers working at the same time, greatly improving spectrum utilization, improving flexibility of wireless planning, improving cell service capacity, transmission rate, and service quality, and improving user experience. DRAWINGS

1 is a schematic diagram of a carrier trunk 4 in a frequency domain adjacent to three carriers in a CDMA system; FIG. 2 is a schematic diagram of a single carrier modulation scheme in a wireless communication system;

3 is a flow chart of a method for reducing multi-carrier mutual interference according to the present invention;

4 is a schematic structural view of a parameter selection device of the present invention;

5 is a schematic structural diagram of adjusting a modulation signal by using a parameter selection device according to the present invention; FIG. 6 is a schematic structural diagram of a device for reducing interference interference during carrier multi-level modulation according to the present invention; FIG. 7 is a schematic structural diagram of a device for reducing multi-carrier mutual interference according to the present invention; . detailed description

The basic idea of the present invention is: In a multi-carrier system, especially between adjacent carriers in the frequency domain, mutual interference is relatively serious. The present invention controls the phase of the modulated signal of each carrier to control the interference between the multiple carriers to the level at which the effective signal in the modulated signal can be correctly demodulated. Since the phase of the modulated signal is related to the carrier frequency and initial phase of the carrier, and the carrier frequency of the carrier has been planned by the communication system, it is a non-adjustable parameter. Therefore, the present invention mainly adjusts the initial phase of the modulated signal. To reduce interference between multiple carriers. The solution of the invention realizes the single and practical.

The present invention will be further described in detail below with reference to the accompanying drawings.

The transmission signal in a modern wireless communication system realizes information transmission by modulating information onto a modulated signal, wherein the modulated signal can be generated by a device such as a Numerical Control Oscillator (NCO) or an analog oscillator. The modulation process can be implemented by the modulator Multiple types of modulators, such as digital modulators, complex modulators, or quadrature modulators, are used to accomplish this.

There are many parameters that reflect the characteristics of the modulated signal, and the frequency and phase are two of them. For example, the signal C (t) modulated by the modulated signal can be expressed as: C (t) = A (t) xcos (2π ή + θ ) + jxA (t) xsin (2π ή + θ ) ₀ where A (t) is the amplitude , is a variable related to time t and baseband signal, f is the carrier frequency, Θ is the initial phase of the modulated signal, and (2πίΐ+θ) is the phase of the modulated signal, which is a phase with frequency ^ time t and initial phase Θ The related function is uniformly represented by W (t, f, θ ) in the present invention, and the cylinder is called I. If it is real modulation, only the real part in C (t) needs to be used.

In the conventional multi-carrier wireless communication system, only the frequency of the modulated signal is specified to reduce inter-carrier interference, and the phase W of the modulated signal is not specifically specified to achieve the purpose of reducing inter-carrier interference.

The phase W of the signal modulated by the modulated signal is a function related to the frequency f, the time t and the initial phase ,, where t is a change in time, indicating the characteristic of the signal, which is uncontrollable. f and Θ are two controlled variables, and the purpose of adjusting the phase W of the modulated signal can be achieved by changing either or both of them. In the wireless communication system, the center frequency of the transmitted carrier has strict requirements, and the offset range of f is relatively narrow, so the flexibility of adjustment is weak, and the initial phase Θ has a large adjustment range and flexibility. The technical solution of the present invention is proposed in response to this feature.

This will be further clarified below by means of the figures.

2 is a schematic diagram of a single carrier modulation mode in a wireless communication system. As shown in FIG. 2, the figure includes two components, a modulator 200 and a modulated signal generator 201. The modulator 200 is configured to modulate the input signal X onto the modulated signal to obtain an output signal y. The input signal is also referred to as a baseband signal, and the output signal includes a modulated baseband signal, that is, a modulated signal. Modulator 200 can be a real number modulator, a complex debugger or a quadrature modulator or the like commonly used in wireless communication systems. The modulated signal generator 201 generates a modulated signal in accordance with the input parameters. Only two input parameters are shown in the figure, respectively frequency parameter The number f and the initial phase parameter Θ. The invention aims to reduce the initial phase of the output signal y to reduce the interference between the carriers.

3 is a flowchart of a method for reducing multi-carrier mutual interference according to the present invention. As shown in FIG. 3, the method for reducing multi-carrier mutual interference according to the present invention includes the following steps:

In step 301, input parameters of the parameter selection means are set, and the parameters may include information parameters indicating an input signal (modulation signal or baseband signal).

In step 302, the output signal (modulated signal) of the communication system is demodulated to correctly demodulate the baseband signal as a basis for selecting the modulated signal.

In step 303, it is determined whether the current modulated signal (output signal) meets the requirements according to the signal demodulation result obtained in step 302. If the requirement is not met, step 304 is performed, and when the requirement is reached, step 305 is performed.

In step 304, based on the above demodulation result (when the baseband signal cannot be correctly demodulated), the initial phase of the next set of modulated signals is calculated according to the optimization algorithm as a new initial phase of each modulated signal. Step 301, step 302, step 303, and step 304 are repeated until an initial phase of a set of modulated signals is found such that the output signal can properly demodulate the baseband signal.

In step 305, the resulting initial phase is solidified as a modulated signal group using the initial phase of a particular configuration.

4 is a schematic diagram of a parameter selection apparatus according to the present invention. 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 can be a specially designed circuit or a dedicated or general purpose instrument. The phase selection software can be software running in the CPU or software running in the programmable logic device or both, and the software can also be solidified and run in the form of hardware. Several input parameters required for the parameter selection apparatus of the present invention to operate include: a carrier type parameter n, a carrier number parameter m, and a carrier center frequency information k. In actual use, depending on the system or carrier, only some or all of the input parameters may be used. The output parameters of the parameter selection device of the present invention include the initial phase parameters of the modulated signal The number selection result indicates a signal. The result indication signal indicates an operational state of the parameter selection device, and the end state is still in operation. The parameter selection device of the present invention operates according to the parameter selection number in Fig. 3, and can be used before the system is operated or during system operation. The main purpose of the parameter selection device of the present invention is to generate an initial phase of each modulated signal and output it to each modulated signal, so that the initial phase of each modulated signal is outputted with the initial phase value output by the parameter selecting means as an initial phase.

FIG. 5 is a schematic structural diagram of adjusting a modulation signal by using a parameter selection device according to the present invention. As shown in FIG. 5, the modulator group may be various modulator types used in a wireless communication system, and its function is to complete multi-carrier modulation. The modulator group has two input signals, one is the input carrier signal, ie, the modulated signal XI ... Xm, and the other is the modulated signal l..m output by the modulated signal generator group. The combiner is used to combine the modulated m single carriers. The coupler is used to feed the output signal back into the parameter selection device of the present invention as an input parameter to the parameter selection device. Together with other input parameters, the parameter selection device of the present invention will perform the initial phase parameter selection in accordance with a certain optimization algorithm. Finally, the selected initial phase is set to each modulated signal. The function of the parameter selection means is the same as that of the parameter selection means shown in FIG. It should be noted that the present invention further includes a demodulator (not shown) for demodulating the modulated signal, and the output modulated signal can be multiplexed and input to the demodulator, and the demodulator is demodulated. The result is input to the parameter selection device of the present invention as a basis for whether or not to continue adjusting the initial phase of the modulated signal. The demodulator can be used with an existing demodulator.

The following is a three-carrier CDMA system as an example, and the method shown in FIG. 3 is used to further clarify the essence of the technical solution of the present invention.

Step 301: Set the input parameters. Input parameters include relevant parameters that represent the input signal. For example: the type of input carrier, in this example is the CDMA IX signal; the number of input carriers, In this example, it is a three-carrier; the center frequency information of the input carrier, the 871.11MHz carrier, the 872.34MHz carrier, and the 873.57MHz carrier of the configuration of the adjacent carrier in this example; the initial phase parameter of the input modulated signal, in this example, the modulation The initial phase of the post signal will be obtained by a function of a random series generator, and the generator seed will be set to zero at the first time. The three carrier phase initial values obtained by seed 0 are used as input parameters.

The invention demodulates the baseband signal in the modulated signal by setting a demodulating device, and compares it with the pre-configured baseband signal. If the same, the interference between the modulated signals is considered to meet the communication requirement, otherwise the communication requirement is not met. Continue to adjust the initial phase value of each modulated signal until the baseband signal is properly demodulated. The demodulating means can be implemented by hardware or software, and can be any of the existing demodulator or software implemented by a demodulating algorithm.

Step 302: Demodulate the baseband signal in the modulated signal. The process of signal demodulation is the inverse process of signal modulation, that is, the channel of the modulated signal is determined by channel estimation or the like, and the baseband signal is demodulated.

Step 303: The comparison result of the baseband signal demodulated in step 302 and the pre-configured baseband signal is used as a basis for phase selection of the modulated signal. If the demodulated baseband signal is the same as the pre-configured baseband signal, exit the phase adjustment process, and proceed to step 305, otherwise proceed to step 304;

Step 304: Adjust the step amount (adjustment amount), and return to step 301 to further adjust the initial phase of the modulated signal.

The initial phase adjustment algorithm of the modulated signal is a cyclical process that exits the loop until the demodulated baseband signal meets the requirements. The initial phase adjustment process of the present invention will be described in detail below.

First, the number from the largest to the smallest is given in order from the frequency parameter of the modulated signal. In this example, the number corresponding to 1.23MHz is 1, the number corresponding to 0MHz is 2, and the number corresponding to 1.23MHz is 3. The priority of the signal phase setting after modulation will be according to the modulation signal. Number to determine. If it is an adjacent configuration, the lowest priority has the lowest priority, the highest priority is second, and the other numbers have the highest priority in the order of the number. If the carrier is a non-adjacent configuration, the modulated signal number is the priority, and the greater the priority, the higher the priority. After the setting is completed, an array with the priority and the modulated signal number in one-to-one correspondence and arranged from high to low will be obtained. This example is for the case where the carrier frequency of the carrier is continuous. Therefore, the priority corresponding to the modulated signals of each number is: Number 1 corresponds to 1, Number 2 corresponds to 3, and Number 3 corresponds to 2. The higher the priority level, the higher the priority.

In the initial phase adjustment, it is necessary to set the stepping amount (adjustment amount) for each adjustment. The coarse adjustment step amount set by the present invention is 20°, and the stepping amount is gradually reduced when the requirement is not satisfied, until the appropriate initial phase is determined. .

Taking the step size as 20° as an example to illustrate how the present invention implements the initial phase adjustment of the carrier. Change the initial phase of carrier 1, 2, 3 (generally with an initial phase of 0. Start), note that the initial phase change of the carrier here is not the same as the initial phase change of the three carriers. When adjusting the initial phase of the carrier, if the three carriers adjust the same amount of steps each time, the initial phase change corresponding to the three carriers is always 0. The interference between them will always be the same, and this phase adjustment is meaningless. The invention is to determine each phase value corresponding to each carrier (in increments of an integer multiple of the step amount) between each phase value corresponding to other carriers (in increments of integer multiples of the step size) In the case of the least interference, each carrier (modulated signal) with the least interference is used as the modulated signal of the baseband signal.

As described above, the initial phase change value of each carrier can be realized by the foregoing parameter selection device, as long as the corresponding carrier increase and decrease flag is set for each carrier according to the set program (incremented by an integral multiple of the aforementioned step size). Quantity), as long as the interference between all the initial phase values between the carriers is determined.

When the step size is 20. When the baseband signals of each carrier can be correctly demodulated at the same time, the stepping amount is adjusted, for example, adjusted to 10°, and each of the above-mentioned manners is determined again. When there are various initial phases between carriers, the interference between each carrier (whether each carrier can demodulate the baseband signal), each modulated signal can correctly demodulate the modulated signal of the baseband signal as output signal. If the modulated signal of the baseband signal of each carrier cannot be determined when the stepping amount is 20°, the stepping amount is further adjusted, for example, adjusted to 5° or 1°, and the initial phase of each carrier is still performed as described above. The adjustment is performed to determine the modulated signal that each carrier can correctly demodulate the baseband signal.

It should be noted that the initial phase of each carrier may be simultaneously adjusted, that is, the initial phase of each carrier is changed at the same time (the initial phases of the carriers are not the same at the same time), thereby determining that each carrier can be correctly demodulated. The modulated signal of the baseband signal. The initial phase of each carrier may be sequentially adjusted, that is, the initial phase of one or more carriers is first changed, and the initial phase of at least one of the carriers is unchanged, thereby determining that each carrier can correctly demodulate the baseband. The modulated signal of the signal. Regardless of how the initial phase is adjusted, the way to determine the modulated signal is the same.

It should be noted that the present invention is also applicable to the case of three or more carrier adjustments. Specifically, the step size of the carrier initial phase adjustment is respectively set according to the foregoing manner, and each carrier is in various types according to the set step amount. The interference condition of the initial phase (in increments of integer multiples of the step size) until it is determined that each carrier can correctly demodulate the modulated signal of the baseband signal as an output signal of each carrier.

Step 305: The initial phase of the carrier is solidified, that is, the modulated signal of the current determined initial phase value is determined as an output signal.

FIG. 6 is a schematic structural diagram of a device for reducing interference in a carrier multi-level modulation according to the present invention. As shown in FIG. 6, it is an application situation of m-carrier n-level modulation. The modulator group, the modulated signal generator group, the combiner and the coupler in the figure have the same functions as the devices shown in Fig. 5, and the modulator groups of each stage are used to modulate the corresponding modulated signals to the modulated signals. on. The multi-level modulation can selectively adjust the initial phase of the modulated signal of one or more stages. The invention is for multi-level modulation The adjustment of the initial phase of the modulated signal will be described. Overall, the initial phase adjustment of the modulated signal in multi-level modulation is exactly the same as the initial phase adjustment of the signal after single-stage modulation. The difference is that the multi-level modulation determines whether the final output modulated signal is correct. The baseband signal is demodulated to determine whether the adjustment is over. When the final output modulated signal can correctly demodulate the baseband signal, the modulated signals determined by each stage serve as the output signals of the stages. In the present invention, a demodulator (not shown) for demodulating the modulated signal outputted from the last stage is further included, and the modulated signal of the last stage output may be multiplexed and input to the corresponding demodulator. The demodulation result of the demodulator is input to the parameter selection device of the present invention as a basis for whether or not to continue adjusting the initial phase of the modulated signal. The demodulator can be selected from an existing demodulator.

When the modulation mode of the modulation signal is cascading modulation, the initial phase of the corresponding modulated signal is adjusted step by step from the modulation signal corresponding to the first-stage modulation, and the adjustment manner is basically the same as the method shown in FIG. 3 described above. Only the judgment standard is different. When the modulated signal outputted by the last stage can correctly demodulate the baseband signal, the modulated signal determined by each level of modulation is used as the output signal of each stage.

The technical solution described in the present invention is also suitable for a multi-carrier operation mode of different types of multi-carriers, such as a hybrid configuration of carrier EV-DO signals and carrier IX signals in a CDMA system.

For the interference problem between carriers in different communication systems, the initial phase adjustment step amount of the carrier is still set separately in the foregoing manner, and the signals are in various phases after each modulation (in increments of integer multiples of the step size) When each modulated signal can correctly demodulate the baseband signal, each modulated signal can correctly demodulate the modulated signal of the baseband signal as an output signal. The initial phase adjustment between different communication systems is no different from the initial phase of the carrier in the same system. The standard is still that each carrier can correctly demodulate the baseband signal.

The technical solution described in the present invention is also suitable for wireless communication systems of other standards, Wideband Code Division Multiple Access (WCDMA) system and Time Division Synchronous Code Division Multiple (TD-SCDMA, Time Division-Synchronous Code Division Multiple). Access) system.

FIG. 7 is a schematic structural diagram of a device 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. The adjusting unit 70 is configured to adjust a phase of the at least one modulated signal; the demodulating unit 71 is configured to demodulate each modulated signal; and the determining unit 72 determines whether the baseband signal can be correctly demodulated from each modulated signal. When there is a modulated signal that cannot be correctly demodulated, the trigger adjustment unit 70 further adjusts the phase of at least one of the modulated signals until the baseband signal is correctly demodulated from each of the modulated signals; When demodulating, the trigger determining unit 73; the determining unit 73 is configured to use the current modulated signals as output signals. The adjusting unit 70 simultaneously adjusts the phase of the modulated signal of each carrier. The adjusting unit 70 sequentially adjusts the modulated signals of the respective carriers. The phase of the modulated signal includes the carrier frequency of the modulated signal and the initial phase of the modulated signal. The adjustment unit 70 adjusts the initial phase of the modulated signal.

When the modulation mode of the modulation signal is cascade modulation, the adjustment 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 determination unit 72 determines the output of the last stage output. When the modulated signal can correctly demodulate the baseband signal, the determining unit 73 uses each modulated signal determined by each level 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. With reference to the related description in the foregoing method for reducing multi-carrier mutual interference, it is understood that the functions of each unit can be implemented by a program running on a processor or by a corresponding logic circuit.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

Claim

A method for reducing mutual interference of multiple carriers, comprising:

Adjusting the phase of at least one modulated signal;

2. The method according to claim 1, wherein the adjusting the phase of the at least one modulated signal is: adjusting the phase of the modulated signal of each carrier simultaneously.

The method according to claim 1, wherein the adjusting the phase of the at least one modulated signal is specifically: sequentially adjusting the modulated signals of the carriers.

The method according to claim 1, wherein when the modulation mode of the modulation signal is cascade modulation, the phase of the corresponding modulated signal is stepwisely stepped from the modulation signal corresponding to the first level modulation. The adjustment is performed until each of the modulated signals outputted in the last stage can correctly demodulate the baseband signal, and each modulated signal determined by each level of modulation is used as an output signal.

The method according to any one of claims 1 to 4, characterized in that the phase of the modulated signal comprises a carrier frequency of the modulated signal and an initial phase of the modulated signal.

6. The method according to claim 4, wherein the adjusting the phase of the modulated signal is to adjust an initial phase of the modulated signal.

A device for reducing mutual interference of multiple carriers, comprising: an adjusting unit, a demodulating unit, a determining unit, and a determining unit, wherein:

a demodulation unit, configured to demodulate each modulated signal;

a determining unit, configured to determine whether the baseband signal can be correctly demodulated from each modulated signal, and if there is a modulated signal that cannot be correctly demodulated, triggering the adjusting unit to further adjust the modulation At least one phase of the modulated signal in the signal until the baseband signal is correctly demodulated from each of the modulated signals; when both are correctly demodulated, the determining unit is triggered;

8. The apparatus according to claim 7, wherein the adjustment unit simultaneously adjusts the phase of the modulated signal of each carrier.

9. The apparatus according to claim 7, wherein the adjustment unit sequentially adjusts the modulated signals of the respective carriers.

The device according to claim 7, wherein when the modulation mode of the modulation signal is cascading modulation, starting from a modulation signal corresponding to the first-stage modulation, the adjustment unit adjusts the corresponding modulation step by step. The phase of the post signal is adjusted until the determining unit determines that each modulated signal outputted by the last stage can correctly demodulate the baseband signal, and the determining unit modulates the determined modulated signals by each level. As an output signal.

The apparatus according to any one of claims 7 to 10, characterized in that the phase of the modulated signal comprises a carrier frequency of the modulated signal and an initial phase of the modulated signal.

12. Apparatus according to claim 11 wherein said adjustment unit adjusts an initial phase of said modulated signal.