CN105790848A - Carrier phase estimation method and device - Google Patents

Abstract

The invention provides a carrier phase estimation device. The carrier phase estimation device comprises a signal quadruplicate phase angle determining unit, an accumulated phase angle jump value determining unit and a carrier phase compensation angle value determining unit; the signal quadruplicate phase angle determining unit is used for carrying out quadruplicate operation for a received signal and determining a quadruplicate signal phase angle; the accumulated phase angle jump value determining unit is used for determining an accumulated phase angle jump value based on the quadruplicate phase angle; and the carrier phase compensation angle value determining unit is used for determining a compensation angle value of a carrier phase based on the quadruplicate signal phase angle and the accumulated phase angle jump value. The invention also provides a carrier phase estimation method.

Description

Carrier phase estimation method and device

Technical Field

The present invention relates to optical communication technologies, and in particular, to a carrier phase estimation method and apparatus in optical fiber communication.

Background

As internet traffic increases, the capacity demanded by optical communication systems in internet backbone systems also increases. As the wavelength bit rate increases, chromatic dispersion, polarization mode dispersion, and waveform distortion of various nonlinear effects on the transmission path may cause severe degradation of information quality.

The digital coherent technology is used as a key technology of a high-speed optical communication system, and compared with the incoherent technology, the digital coherent technology has the following advantages: an optical signal to noise ratio (OSNR) gain of about 3 dB; the electric equalization technology can be conveniently adopted to deal with the channel change, thereby reducing the cost; in addition, the digital coherent technology can also adopt a more efficient modulation technology and polarization multiplexing to improve the transmission capacity; therefore, the digital coherent technology is considered as a key technology of a high-speed optical communication system.

In a coherent optical communication system, since a laser at a transmitting end and a local oscillator laser at a receiving end both have a certain line width, phase recovery is necessary to obtain a correct signal at the receiving end.

However, most of the unwrapping (unwrap) methods involved in the current phase recovery process are serial operations or more complex parallel operations, such as the current typical parallel unwrapping is implemented by two steps: firstly, adjusting phase deviation in a parallel section; secondly, adjusting phase deviation between parallel sections; the realized unwrapping circuit has a complex realization structure and large delay.

From the process, the existing serial unwrapping method for phase estimation is low in efficiency, and the parallel unwrapping method is complex in implementation, large in circuit scale, large in delay and large in power consumption. Therefore, an efficient parallel unwrapping implementation method is needed to efficiently implement carrier phase estimation.

Disclosure of Invention

In view of this, embodiments of the present invention are intended to provide a method and an apparatus for carrier phase estimation, which solve the problems of complex implementation, large circuit scale, large delay, large power consumption, and the like of the existing parallel unwrapping method.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

the embodiment of the invention provides a carrier phase estimation device, which comprises: the device comprises a signal quadratically phase angle determining unit, an accumulated phase angle jump value determining unit and a compensation angle value determining unit of a carrier phase; wherein,

the signal fourth power phase angle determining unit is used for performing fourth power operation on the received signal and determining a fourth power signal phase angle;

the accumulated phase angle jump value determining unit is used for determining an accumulated phase angle jump value according to the fourth power phase angle;

and the compensation angle value determining unit of the carrier phase is used for determining the compensation angle value of the carrier phase according to the signal phase angle of the fourth power and the accumulated phase angle jump value.

In the above scheme, the signal fourth power phase angle determining unit is specifically configured to:

taking the fourth power of the received signal after the frequency offset compensation to obtain a fourth power signal;

and averaging the quadrivalent power signal to determine the phase angle of the quadrivalent power signal.

In the above scheme, the accumulated phase angle jump value determining unit includes a phase angle difference subunit, a rounding subunit, and an accumulation subunit, where:

the phase angle difference molecular unit is used for carrying out difference on the phase angle of the quadrivalent power signal to determine a difference phase angle;

the rounding subunit is configured to round the differential phase angle and determine a phase angle jump value;

and the accumulation subunit is used for accumulating the phase angle jump value, and determining an accumulated phase angle jump value by modulo 4 with respect to the accumulated phase angle jump value.

In the above solution, the compensation angle value determining unit for the carrier phase includes a unwrapping carrier phase value determining subunit and a compensating unit; wherein,

the phase value determining subunit is configured to divide the sum of the quadrivalent signal phase angle and the accumulated phase angle jump value by 4 to determine a phase value of a unwrapped carrier;

and the compensation unit is used for compensating the phase value of the unwrapped carrier and determining a compensation angle value of the carrier phase.

In the foregoing solution, the compensation unit is specifically configured to: and adding 1/8 revolutions to the phase value of the unwrapped carrier to obtain a compensation angle value of the carrier phase.

The embodiment of the invention also provides a carrier phase estimation method, which comprises the following steps:

performing a fourth power operation on the received signal to determine a fourth power signal phase angle;

determining an accumulated phase angle jump value according to the fourth power phase angle;

and determining a compensation angle value of the carrier phase according to the quadric signal phase angle and the accumulated phase angle jump value.

In the above scheme, the performing a fourth power operation on the received signal and determining a fourth power signal phase angle includes:

taking the fourth power of the received signal after the frequency offset compensation to obtain a fourth power signal;

and averaging the quadrivalent power signal to determine the phase angle of the quadrivalent power signal.

In the foregoing solution, the determining a cumulative phase angle jump value according to the fourth power phase angle includes:

differentiating the quadrivalent power signal phase angle to determine a differential phase angle;

rounding the differential phase angle and determining a phase angle jump value;

and accumulating the phase angle jump value, and determining the accumulated phase angle jump value by modulo 4.

In the foregoing solution, determining a compensation angle value of a carrier phase according to the signal phase angle of the fourth power and the accumulated phase angle jump value includes:

dividing the sum of the quadrivalent signal phase angle and the accumulated phase angle jump value by 4 to determine a unwrapped carrier phase value;

and compensating the phase value of the unwrapped carrier wave, and determining a compensation angle value of the carrier wave phase.

In the above solution, the compensating the unwrapped carrier phase value and determining the compensation angle value of the carrier phase include, but are not limited to: and adding 1/8 revolutions to the phase value of the unwrapped carrier to obtain a compensation angle value of the carrier phase.

The carrier phase estimation method and the carrier phase estimation device provided by the embodiment of the invention firstly carry out the fourth power operation on the received signal and determine the phase angle of the fourth power signal; determining an accumulated phase angle jump value according to the fourth power phase angle; and then determining a compensation angle value of the carrier phase according to the quadric signal phase angle and the accumulated phase angle jump value. Therefore, the problems of complexity, large circuit scale, large delay, large power consumption and the like in the implementation of the conventional parallel unwrapping method can be solved.

Drawings

FIG. 1 is a flow chart of a typical cubic phase estimation method;

FIG. 2 is a schematic diagram of a carrier phase estimation apparatus according to an embodiment;

fig. 3 is a schematic diagram of an algorithm structure of a phase value determining subunit of an unwrapped carrier according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a binary algorithm of an unwrapped carrier phase value determining subunit according to an embodiment of the present invention;

FIG. 5 is a flowchart illustrating a carrier phase estimation method according to an embodiment of the present invention;

fig. 6 is a flowchart illustrating a method for determining a cumulative phase angle jump value according to an embodiment of the present invention.

Detailed Description

Most of the existing phase estimation algorithms are based on an M-th power algorithm or a maximum likelihood algorithm, and the M-th power algorithm is firstly applied to Quadrature Phase Shift Keying (QPSK) coding phase estimation. Assume that the phase of the kth symbol after equalization and polarization demultiplexing in the coherent receiving system is:θ_k＝θ_s(k)+△ωkT+θ_n+θ_ASEwherein theta_s(k) For the modulation phase of the signal, △ ω kT is the phase error component due to carrier frequency offset, which is removed by the carrier frequency offset estimation and compensation algorithm, θ_nPhase, θ, induced by laser linewidth_ASEFor noise phase, the △ ω kT component should be removed after frequency offset compensation, for QPSK/quadrature relative phase shift keying (DQPSK) modulation, ${\mathrm{\θ}}_s\left(k\right)\∈(\frac{\mathrm{\π}}{4},\frac{3\mathrm{\π}}{4},\frac{5\mathrm{\π}}{4},\frac{7\mathrm{\π}}{4}).$

after squaring the signal after equalization, polarization demultiplexing and frequency offset compensation of the receiving system, the phase of the signal of the kth symbol to the fourth power can be expressed as 4 θ_s(k)+4θ_n+4θ_ASE，4θ_s(k) The value after modulo 2 pi is pi, so performing a fourth power operation can remove the symbol modulation phase. To reduce the noise effect, the fourth power signal may be subjected to a moving average filtering, and then the complex phase of the filtered signal is averaged, and then the angular unwrapping and the division by 4 are performed to obtain the estimated phase value. Fig. 1 is a flow chart of a typical quadratic phase estimation method.

Most of the current coherent optical communication systems adopt QPSK as a modulation format, and in order to further increase transmission capacity, a higher-order modulation format, such as 16 Quadrature Amplitude Modulation (QAM), may be adopted, and the basic steps are: firstly, performing fourth power on symbols, and then grouping the symbols according to the amplitude, for example, grouping the symbols into three groups; removing the fourth power signal in the II group, reserving the I, III th group point, and carrying out the sliding average; then, a plurality of phase angles are obtained to solve the problem of winding. However, most of the existing unwrapping methods are serial operations or more complex parallel operations, such as the existing typical parallel unwrapping method is implemented by two steps: firstly, adjusting phase deviation in a parallel section; secondly, adjusting phase deviation between parallel sections; the realized unwrapping circuit has a complex realization structure and large delay.

In view of the foregoing problems, an embodiment of the present invention provides a carrier phase estimation apparatus, including: the device comprises a signal quadratically phase angle determining unit, an accumulated phase angle jump value determining unit and a compensation angle value determining unit of a carrier phase; the signal fourth power phase angle determining unit is used for performing fourth power operation on the received signal and determining a fourth power signal phase angle; the accumulated phase angle jump value determining unit is used for determining an accumulated phase angle jump value according to the fourth power phase angle; and the compensation angle value determining unit of the carrier phase is used for determining the compensation angle value of the carrier phase according to the signal phase angle of the fourth power and the accumulated phase angle jump value.

In practical application, after equalization and polarization demultiplexing are performed on a 128Gb/s polarization multiplexing-quadrature phase shift keying (PM-QPSK) coherent optical communication receiver, there are two paths of signals of x polarization and y polarization, and after frequency offset compensation is performed on the x polarization signal and the y polarization signal, there is also a phase error component caused by a laser line width, and a phase error needs to be estimated, that is, a compensation angle value of a carrier phase needs to be calculated and compensated. The two paths of signals of x polarization and y polarization need to be subjected to phase estimation respectively, and the input signal of the carrier phase estimation device in the embodiment of the invention is a signal after equalization, polarization demultiplexing and frequency offset compensation are completed. In the case of a polarization multiplexing coherent optical communication system, when there are two polarization signals of x-polarization and y-polarization, carrier phase estimation needs to be performed independently for each signal path, and therefore, two carrier phase estimation devices are required.

The following describes the implementation of the technical solution of the present invention in further detail with reference to the accompanying drawings and specific embodiments. Fig. 2 is a schematic structural diagram of a carrier phase estimation device according to an embodiment of the present invention, and as shown in fig. 2, the carrier phase estimation device according to the embodiment of the present invention includes the following structures: a signal fourth power phase angle determining unit 21, an accumulated phase angle jump value determining unit 22, and a compensation angle value determining unit 23 of a carrier phase; wherein,

the signal fourth power phase angle determining unit 21 is configured to perform fourth power operation on the received signal to determine a fourth power signal phase angle;

in the embodiment of the invention, the received signal is a signal after frequency offset compensation; the signal fourth power phase angle determining unit 21 is specifically configured to: taking the fourth power of the received signal after the frequency offset compensation to obtain a fourth power signal; the quadratic signal is averaged to determine the quadratic signal phase angle, and the determined quadratic signal phase angle is sent to the cumulative phase angle jump value determining unit 22.

Common units of angle include: radians (Radians), Degrees (Degrees), Turns (Turns), etc., and the unit conversion relationship of each angle is: 2 pi radians 360 degrees 1 revolution. In most communication systems, for the convenience of fixed-point implementation, the angle generally adopts Turns (Turns) as a unit. In the embodiment of the present invention, the angle also uses Turns (Turns) as a unit.

The range of the phase angle value of the signal of the fourth power determined by the signal fourth power phase angle determining unit 21 is [0, 1) turns. In the embodiment of the invention, the phase angle of the signal with the fourth power of the kth section symbol is set as theta_Nk+1,......,θ_Nk+NWherein N is parallelism;

when the signal quadratic phase angle determining unit 21 averages the quadratic signal, the quadratic signal may be directly averaged for the QPSK/DQPSK modulation system, and for the 16QAM modulated signal, some existing improved quadratic averaging methods need to be applied, for example, the quadratic signal with medium amplitude is removed, and then the averaging operation is performed.

In the embodiment of the present invention, taking parallelism N-64 as an example, the signal input by the signal quadric phase angle determining unit 21 is a frequency offset compensated signal with parallelism 64; the signal quartic phase angle determining unit 21 performs quartic operation on the input signal and performs moving average filtering on the quartic signal, which is to take the average value of the quartic signal.

For high-speed symbol streams, the phase noise is a slowly varying signal, and can be regarded as basically constant within a plurality of continuous symbols, so that for a plurality of symbols continuously input to the algorithm, the symbols are regarded as a group, and the finally calculated compensation angle value of the carrier phase is shared by all symbols in the group. In general, the compensation angle values of the carrier phases of several adjacent symbols are not greatly different, so in order to reduce the workload, a decimation operation can be performed on the quadric signals after the sliding average filtering, and only 64/4-16 average filtered quadric signals are output; the four-out-one operation need not be performed. After the four-extraction-one operation is carried out, the parallelism N of each processing unit in the subsequent processing process is 16; then, calculating a complex phase angle of the average filtered quadrivalent signals; algorithms such as Cordic and the like can be adopted for solving the complex phase angle; finally, the signal quartic phase angle determining unit 21 outputs the quartic phase angle with the parallelism of 16 to the accumulated phase angle jump value determining unit 22.

The accumulated phase angle jump value determining unit 22 is configured to determine an accumulated phase angle jump value according to the fourth power phase angle;

in the embodiment of the present invention, the accumulated phase angle jump value determining unit 22 includes: the phase angle difference subunit 221, the rounding subunit 222, and the accumulating subunit 223, and accordingly, the signal quartic phase angle determining unit 21 sends the determined quartic signal phase angle to the accumulated phase angle jump value determining unit 22: the signal fourth power phase angle determining unit 21 sends the determined fourth power signal phase angle to the phase angle difference subunit 221; specifically, the method comprises the following steps:

the phase angle difference subunit 221 is configured to perform difference on the phase angle of the fourth power signal, determine a difference phase angle, and send the difference phase angle to the rounding subunit 222;

the phase angle difference subunit 221 performs difference on the phase angle of the fourth power signal, and determining a difference phase angle includes: subtracting two adjacent quadrivalent power signal phase angles to obtain a difference phase angle_Nk+i：

_Nk+i＝θ_Nk+i-θ_Nk+i-1；i＝1,......N；

Wherein, the value range of the differential phase angle is (-1, 1) turns.

Still taking the above example as an example, the 1 st element of the differential phase angle is: the last 1 element of the fourth power signal phase angle of the previous beat minus the 1 st element of the fourth power signal phase angle. When the signal fourth power phase angle determining unit 21 performs a fourth decimation operation on the fourth power signal after the moving average filtering, the value range of i is: i is 2, …,16, and the i-th element of the differential phase angle is: the i-1 th element of the fourth power signal phase angle minus the i-th element of the fourth power signal phase angle.

The rounding sub-unit 222 is configured to round the differential phase angle, determine a phase angle jump value, and send the phase angle jump value to an accumulation unit;

in the embodiment of the present invention, the rounding subunit 222 rounds the differential phase angle to a round.

The specific implementation manner of rounding the differential phase angle by the rounding subunit 222 is as follows: adding 0.5 to the differential phase angle, and then rounding down by using a floor function; the rounded value of the rounding sub-unit 222 can beCan be-1, 0, in order to obtain the phase angle jump value of the non-negative integer, the rounding subunit 222 modulo 4 the rounded value to obtain the phase angle jump value △ of the non-negative integer_Nk+1：

△_Nk+1＝mod(floor(θ_Nk+i+0.5),4)；i＝1,......N；

Wherein floor represents the lower integer, mod (.,4) represents the modulo 4 operation; the value range of the phase angle jump value of the non-negative integer is {3,1,0 }; the specific implementation can be represented by 2-bit unsigned binary numbers.

The accumulation subunit 223 is configured to accumulate the phase angle jump value, modulo 4 the accumulated phase angle jump value, and determine an accumulated phase angle jump value; the accumulated phase angle jump value is then sent to the compensation angle value determination unit 23 for the carrier phase.

The accumulation subunit 223, when accumulating the phase angle jump value, inputs the phase angle jump value of parallelism N and outputs the accumulated phase angle jump value of parallelism N, the accumulation subunit 223 includes a state register and N summation modules, wherein, when the signal fourth power phase angle determining unit 21 performs a four-decimation operation on the fourth power signal after the sliding average filtering, the parallelism N is 1/4, that is, when the initial value of N is 64, N is 16 after the four-decimation operation, the accumulation subunit 223 includes 16 summation modules, the initial value of the state register is 0, the ith summation module sums up the i +1 numbers of the state register value and the phase angle jump value from the 1 st element value to the ith element value to obtain the ith element η of the accumulated phase jump value_Nk+i：

$\left\{\begin{array}{c}{\mathrm{\η}}_{\mathrm{Nk}+1}=\mathrm{mod}({\mathrm{\η}}_{N(k-1)+N}+\underset{i=1}{\overset{1}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{\mathrm{Nk}+i},4)\\ .\\ .\\ .\\ {\mathrm{\η}}_{\mathrm{Nk}+j}=\mathrm{mod}({\mathrm{\η}}_{N(k-1)+N}+\underset{i=1}{\overset{j}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{\mathrm{Nk}+i},4)\\ .\\ .\\ .\\ {\mathrm{\η}}_{\mathrm{Nk}+N}=\mathrm{mod}({\mathrm{\η}}_{N(k-1)+N}+\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{\mathrm{Nk}+i},4)\end{array}\right\}$

Here, i is 1,2, …, N; mod (, 4) represents the modulo 4 operation. In a specific implementation process, the input of the summing module is a plurality of 2-bit unsigned binary numbers, and the output is also a 2-bit unsigned binary number; the result of the summing module only retains the low-end 2 bits, the summing overflow is discarded, and the last element of the product phase angle jump value, i.e. the value of the nth element of the phase angle jump value, is assigned to the status register.

And the compensation angle value determining unit 23 of the carrier phase is configured to determine a compensation angle value of the carrier phase according to the signal phase angle of the fourth power and the accumulated phase angle jump value.

Specifically, the compensation angle value determination unit 23 for carrier phase comprises a unwrapping carrier phase value subunit 231 and a compensation unit 232, wherein,

the unwrapped carrier phase value determining subunit 231, configured to divide the sum of the quadrivalent signal phase angle and the accumulated phase angle jump value by 4, and determine an unwrapped carrier phase value;

fig. 3 is a schematic diagram of an algorithm structure of the unwrapping carrier phase value determining subunit 231 according to an embodiment of the present invention, and as shown in fig. 3, the unwrapping carrier phase value determining subunit 231 determines the phase angle θ of the fourth power signal_Nk+iAnd the accumulated phase angle jump value η_Nk+iDividing by 4 to determine the unwrapped carrier phase value;

fig. 4 is a schematic diagram of a binary algorithm structure of the unwrapped carrier phase value determining subunit 231 according to the embodiment of the present invention, as shown in fig. 4: theta_Nk+iIs an M-bit binary number, η_Nk+iThe unwrapped carrier phase value determining subunit 231 combines the two-bit accumulated phase angle jump value and the M-bit quadrivalent signal phase angle value into an M + 2-bit binary number, wherein the high-end 2 bit of the M + 2-bit binary number is the accumulated phase angle jump value, and the rest low-end bits are the quadrivalent signal phase angle value; in the embodiment of the present invention, the combination of the two-bit accumulated phase angle jump value and the M-bit fourth power signal phase angle is to perform bit combination of the accumulated phase angle jump value and the fourth power signal phase angle, the accumulated phase angle is used as a high-end bit, and the fourth power signal phase angle is used as a low-end bit.

The compensation unit 232 is configured to compensate the phase value of the unwrapped carrier, and determine a compensation angle value of the carrier phase; the method comprises the following steps: and adding 1/8 revolutions to the phase value of the unwrapped carrier to obtain a compensation angle value of the carrier phase.

In the embodiment of the present invention, in order to ensure that the finally determined compensation angle value of the carrier phase is located between four quadrants, rather than on four coordinate axes, 1/8 rotations need to be added to the phase value of the unwrapped carrier phase to obtain the final compensation angle value of the carrier phase.

An embodiment of the present invention further provides a carrier phase estimation method, fig. 5 is a schematic flow chart of the carrier phase estimation method according to the embodiment of the present invention, and as shown in fig. 5, the carrier phase estimation method according to the embodiment of the present invention includes the following steps:

step 501: performing a fourth power operation on the received signal to determine a fourth power signal phase angle;

in the embodiment of the present invention, said performing a fourth power operation on the received signal, and determining a phase angle of the fourth power signal includes: taking the fourth power of the received signal after the frequency offset compensation to obtain a fourth power signal; and averaging the quadrivalent power signal to determine the phase angle of the quadrivalent power signal.

Common units of angle include: radians (Radians), Degrees (Degrees), Turns (Turns), etc., and the conversion relation of each angle unit is 2 pi Radians-360 Degrees-1 turn. In most communication systems, for the convenience of fixed-point implementation, the angle generally adopts Turns (Turns) as a unit. In the embodiment of the present invention, the angle also uses Turns (Turns) as a unit.

In the embodiment of the invention, the range of the phase angle value of the determined quadrivalent signal is [0, 1 ] revolution. Here, let the phase angle of the signal of the fourth power of the k-th symbol be θ_Nk+1,......,θ_Nk+NWherein N is parallelism;

in this step, when averaging the quadric signals, the quadric signals may be directly averaged for the QPSK/DQPSK modulation system, and for the 16QAM modulated signals, some existing improved quadric averaging methods need to be applied, for example, the quadric signals with medium amplitude are removed, and then the averaging operation is performed.

In the embodiment of the present invention, for example, with the parallelism N being 64, the input signal is first subjected to a fourth power operation, and then the fourth power signal is subjected to a moving average filtering, where the moving average filtering of the fourth power signal is an averaging of the fourth power signal.

For high-speed symbol streams, the phase noise is a slowly varying signal, and can be regarded as basically constant within a plurality of continuous symbols, so that for a plurality of symbols continuously input to the algorithm, the symbols are regarded as a group, and the finally calculated compensation angle value of the carrier phase is shared by all symbols in the group. In general, the compensation angle values of the carrier phases of several adjacent symbols are not greatly different, so in order to reduce the workload, a decimation operation can be performed on the quadric signals after the sliding average filtering, and only 64/4-16 average filtered quadric signals are output; the four-out-one operation need not be performed. After the four-extraction-one operation is carried out, the parallelism N in the subsequent processing process is 16; then, calculating a complex phase angle of the average filtered quadrivalent power signal; algorithms such as Cordic and the like can be adopted for solving the complex phase angle; finally, a quartic phase angle with 16 parallelism is output.

Step 502: determining an accumulated phase angle jump value according to the fourth power phase angle;

fig. 6 is a schematic flow chart of a method for determining a cumulative phase angle jump value according to an embodiment of the present invention, as shown in fig. 6, including the following steps:

step 502A: differentiating the quadrivalent power signal phase angle to determine a differential phase angle;

specifically, subtraction is performed on two adjacent quadrivalent signal phase angles, that is, the adjacent quadrivalent signal phase angle at the back is subtracted from the front quadrivalent signal phase angle to obtain a differential phase angle_Nk+i：

_Nk+i＝θ_Nk+i-θ_Nk+i-1；i＝1,......N；

Wherein, the value range of the differential phase angle is (-1, 1) turns.

Still taking the above example as an example, the 1 st element of the differential phase angle is: the last 1 element of the fourth power signal phase angle of the previous beat minus the 1 st element of the fourth power signal phase angle. When the signal fourth power phase angle determining unit 21 performs a fourth decimation operation on the fourth power signal after the moving average filtering, the value range of i is: i is 2, …,16, and the i-th element of the differential phase angle is: the i-1 th element of the fourth power signal phase angle minus the i-th element of the fourth power signal phase angle.

Step 502B: rounding the differential phase angle and determining a phase angle jump value;

the specific implementation mode is that the differential phase angle is added with 0.5 and then rounded downwards by using a floor function, the rounded values of the rounding subunit 222 can be-1, 1 and 0, in order to obtain the phase angle jump value of a non-negative integer, the rounding subunit 222 modulo 4 the rounded value to obtain the phase angle jump value △ of the non-negative integer_Nk+1：

△_Nk+1＝mod(floor(θ_Nk+i+0.5),4)；i＝1,......N；

Wherein floor represents the lower integer, mod (.,4) represents the modulo 4 operation; the value range of the phase angle jump value of the non-negative integer is {3,1,0 }; the specific implementation can be represented by 2-bit unsigned binary numbers.

Step 502C: accumulating the phase angle jump value, and determining an accumulated phase angle jump value by modulo 4 of the accumulated phase angle jump value;

specifically, when the phase angle jump value is accumulated, the phase angle jump value of the parallelism N is input, and the accumulated phase angle jump value of the parallelism N is output. Here, when the signal is quadratically phaseThe angle determining unit 21 performs a four-decimation operation on the moving average filtered signal of the fourth power, the parallelism N is 1/4, i.e. when the initial value of N is 64, the parallelism N is 16 after the four-decimation operation, 16 summation modules are needed, the initial value of the state register is 0, the ith summation module sums the state register value and the i +1 number of the phase angle jump value from the 1 st element value to the ith element value, and the ith element η of the accumulated phase angle jump value is obtained_Nk+i：

$\left\{\begin{array}{c}{\mathrm{\η}}_{\mathrm{Nk}+1}=\mathrm{mod}({\mathrm{\η}}_{N(k-1)+N}+\underset{i=1}{\overset{1}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{\mathrm{Nk}+i},4)\\ .\\ .\\ .\\ {\mathrm{\η}}_{\mathrm{Nk}+j}=\mathrm{mod}({\mathrm{\η}}_{N(k-1)+N}+\underset{i=1}{\overset{j}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{\mathrm{Nk}+i},4)\\ .\\ .\\ .\\ {\mathrm{\η}}_{\mathrm{Nk}+N}=\mathrm{mod}({\mathrm{\η}}_{N(k-1)+N}+\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{\Δ}}_{\mathrm{Nk}+i},4)\end{array}\right\}$

Here, i is 1,2, …, N; mod (, 4) represents the modulo 4 operation. In a specific implementation process, the input of the summing module is a plurality of 2-bit unsigned binary numbers, and the output is also a 2-bit unsigned binary number; the result of the summing module only retains the low-end 2 bits, the summing overflow is discarded, and the last element of the product phase angle jump value, i.e. the value of the nth element of the phase angle jump value, is assigned to the status register.

Step 503: determining a compensation angle value of a carrier phase according to the quadric signal phase angle and the accumulated phase angle jump value;

specifically, firstly, dividing the sum of the quadrivalent signal phase angle and the accumulated phase angle jump value by 4 to determine a phase value of the unwrapped carrier wave; and then compensating the phase value of the unwrapped carrier wave to determine a compensation angle value of the carrier wave phase.

The binary algorithm for determining the phase value of the unwrapped carrier by dividing the sum of the signal phase angle of the fourth power and the accumulated phase jump value by 4 is: and combining the accumulated phase angle jump value of two bits and the phase angle value of the M-bit fourth power signal to obtain an M + 2-bit binary number, wherein the high-end 2 bits of the M + 2-bit binary number are the accumulated phase angle jump value, and the rest low-end bits are the phase angle values of the fourth power signal. In the embodiment of the present invention, the combination of the two-bit accumulated phase angle jump value and the M-bit fourth power signal phase angle is to perform bit combination of the accumulated phase angle jump value and the fourth power signal phase angle, the accumulated phase angle is used as a high-end bit, and the fourth power signal phase angle is used as a low-end bit.

The compensating the phase value of the unwrapped carrier, and determining a compensation angle value of the carrier phase includes: and adding 1/8 revolutions to the phase value of the unwrapped carrier to obtain a compensation angle value of the carrier phase.

In the embodiment of the present invention, in order to ensure that the finally determined compensation angle value of the carrier phase is located between four quadrants, rather than on four coordinate axes, 1/8 rotations need to be added to the phase value of the unwrapped carrier phase to obtain the final compensation angle value of the carrier phase.

The implementation functions of the processing units in the carrier phase estimation apparatus shown in fig. 2 can be understood with reference to the related description of the carrier phase estimation method. Those skilled in the art will understand that the functions of the processing units in the carrier phase estimation apparatus shown in fig. 2 can be implemented by a program running on a processor, and can also be implemented by specific logic circuits, such as: can be realized by a Central Processing Unit (CPU), a Microprocessor (MPU), a Digital Signal Processor (DSP) or a Field Programmable Gate Array (FPGA); the storage unit may also be implemented by various memories, or storage media.

In the embodiments provided in the present invention, it should be understood that the disclosed method and apparatus may be implemented in other ways. The above-described device embodiments are merely illustrative, for example, the division of the unit is only a logical functional division, and there may be other division ways in actual implementation, such as: multiple units or components may be combined, or may be integrated into another system, or some features may be omitted, or not implemented. In addition, the communication connections between the components shown or discussed may be through interfaces, indirect couplings or communication connections of devices or units, and may be electrical, mechanical or other.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed on a plurality of network units; some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, all the functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may be separately regarded as one unit, or two or more units may be integrated into one unit; the integrated unit can be realized in a form of hardware, or in a form of hardware plus a software functional unit.

Those of ordinary skill in the art will understand that: all or part of the steps for realizing the method embodiments can be completed by hardware related to program instructions, the program can be stored in a computer readable storage medium, and the program executes the steps comprising the method embodiments when executed; and the aforementioned storage medium includes: various media that can store program codes, such as a removable storage device, a Read-only memory (ROM), a magnetic disk, or an optical disk.

Alternatively, the integrated unit according to the embodiment of the present invention may be stored in a computer-readable storage medium if it is implemented in the form of a software functional unit and sold or used as a separate product. Based on such understanding, the technical solutions of the embodiments of the present invention may be essentially implemented or a part contributing to the prior art may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the methods described in the embodiments of the present invention. And the aforementioned storage medium includes: a removable storage device, a ROM, a magnetic or optical disk, or other various media that can store program code.

The carrier phase estimation method, apparatus and system described in the embodiments of the present invention are only examples of the above embodiments, but not limited thereto, and those skilled in the art should understand that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

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

Claims (10)

1. A carrier phase estimation apparatus, the apparatus comprising: the device comprises a signal quadratically phase angle determining unit, an accumulated phase angle jump value determining unit and a compensation angle value determining unit of a carrier phase; wherein,

the signal fourth power phase angle determining unit is used for performing fourth power operation on the received signal and determining a fourth power signal phase angle;

the accumulated phase angle jump value determining unit is used for determining an accumulated phase angle jump value according to the fourth power phase angle;

and the compensation angle value determining unit of the carrier phase is used for determining the compensation angle value of the carrier phase according to the signal phase angle of the fourth power and the accumulated phase angle jump value.

2. The apparatus of claim 1, wherein the signal quartic phase angle determining unit is specifically configured to:

taking the fourth power of the received signal after the frequency offset compensation to obtain a fourth power signal;

and averaging the quadrivalent power signal to determine the phase angle of the quadrivalent power signal.

3. The apparatus of claim 1, wherein the accumulated phase angle jump value determining unit comprises a phase angle difference subunit, a rounding subunit, and an accumulation subunit, wherein:

the phase angle difference molecular unit is used for carrying out difference on the phase angle of the quadrivalent power signal to determine a difference phase angle;

the rounding subunit is configured to round the differential phase angle and determine a phase angle jump value;

and the accumulation subunit is used for accumulating the phase angle jump value, and determining an accumulated phase angle jump value by modulo 4 with respect to the accumulated phase angle jump value.

4. The apparatus of claim 1, wherein the compensation angle value determining unit for the carrier phase comprises a unwrapping carrier phase value determining subunit, a compensating unit; wherein,

the phase value determining subunit is configured to divide the sum of the quadrivalent signal phase angle and the accumulated phase angle jump value by 4 to determine a phase value of a unwrapped carrier;

and the compensation unit is used for compensating the phase value of the unwrapped carrier and determining a compensation angle value of the carrier phase.

5. The apparatus according to claim 4, wherein the compensation unit is specifically configured to: and adding 1/8 revolutions to the phase value of the unwrapped carrier to obtain a compensation angle value of the carrier phase.

6. A method for carrier phase estimation, the method comprising:

performing a fourth power operation on the received signal to determine a fourth power signal phase angle;

determining an accumulated phase angle jump value according to the fourth power phase angle;

and determining a compensation angle value of the carrier phase according to the quadric signal phase angle and the accumulated phase angle jump value.

7. The method of claim 6, wherein said squaring the received signal and determining a square signal phase angle comprises:

taking the fourth power of the received signal after the frequency offset compensation to obtain a fourth power signal;

and averaging the quadrivalent power signal to determine the phase angle of the quadrivalent power signal.

8. The method of claim 6, wherein said determining a cumulative phase angle jump value from said fourth power phase angle comprises:

differentiating the quadrivalent power signal phase angle to determine a differential phase angle;

rounding the differential phase angle and determining a phase angle jump value;

and accumulating the phase angle jump value, and determining the accumulated phase angle jump value by modulo 4.

9. The method of claim 6, wherein said determining a compensation angle value for a carrier phase based on said fourth power signal phase angle and said accumulated phase angle jump value comprises:

dividing the sum of the quadrivalent signal phase angle and the accumulated phase angle jump value by 4 to determine a unwrapped carrier phase value;

and compensating the phase value of the unwrapped carrier wave, and determining a compensation angle value of the carrier wave phase.

10. The method of claim 9, wherein the compensating the unwrapped carrier phase value comprises, but is not limited to: and adding 1/8 revolutions to the phase value of the unwrapped carrier to obtain a compensation angle value of the carrier phase.