CN109286588B - Method for estimating initial phase of binary phase shift keying signal - Google Patents

Abstract

The invention discloses a binary phase shift keying signal initial phase estimation method, which firstly constructs a binary phase shift keying signal initial phase estimation platform, and the constructed system comprises: the system comprises a signal sampling module, an FFT module, a carrier frequency estimation module and an initial phase estimation module, wherein the signal sampling module is used for sampling binary phase shift keying signals to form a sampling sequence, the FFT module is used for carrying out FFT processing on the sampling sequence, the carrier frequency estimation module is used for estimating a carrier frequency according to the FFT processing result, and the initial phase estimation module is used for estimating the initial phase of the binary phase shift keying signals. The method can estimate the initial phase of the binary phase shift keying signal, has high accuracy of the estimated initial phase and can meet the use requirement.

Description

Method for estimating initial phase of binary phase shift keying signal

Technical Field

The invention relates to a signal initial phase estimation method, in particular to a binary phase shift keying signal initial phase estimation method.

Background

After the spread spectrum receiver works, it needs to perform initial phase parameter estimation on the received binary phase shift keying signal, so as to perform subsequent signal processing work. The binary phase shift keying signal belongs to phase modulation, the phase of the modulated signal is directly controlled by the digital baseband signal, and the amplitude and frequency of the modulated signal are kept unchanged. The commonly used method for estimating the initial phase of the signal is as follows: sampling the binary phase shift keying signal to form a sampling sequence; carrying out carrier frequency estimation and initial position estimation on the sampling sequence; performing digital quadrature frequency mixing processing on the sampling sequence by using a quadrature digital local oscillator to form in-phase data and quadrature data; initial phase estimation is performed using the in-phase and quadrature data based on the estimated initial position. Since the initial position estimation accuracy of the binary phase shift keying signal by the method is not very high, the initial phase estimation performance is reduced.

Fast fourier transform, abbreviated FFT, can convert time domain data to frequency domain data.

Disclosure of Invention

The invention aims to provide a binary phase shift keying signal initial phase estimation method, which solves the problem of poor estimation performance of a common signal initial phase estimation method.

A method for estimating an initial phase of a binary phase shift keying signal comprises the following specific steps:

first step, an initial phase estimation platform is established

An initial phase estimation stage comprising: the device comprises a signal sampling module, an FFT module, a carrier frequency estimation module and an initial phase estimation module. The following steps:

the signal sampling module has the functions of: sampling the binary phase shift keying signal to form a sampling sequence;

the function of the FFT module is as follows: performing FFT processing on the sampling sequence;

the carrier frequency estimation module has the functions of: estimating carrier frequency according to the FFT processing result;

the initial phase estimation module functions as: an initial phase of the binary phase shift keyed signal is estimated.

The second step signal sampling module samples the binary phase shift keying signal to form a sampling sequence

The signal sampling module samples a binary phase shift keying signal x (t) to form a sampling sequence x (n) with a sampling frequency f_sWith a sampling time interval of T_s，T_s＝1/f_s(ii) a t is a time parameter, N is a time domain point index value, N is 0,1, …, N-1, and N is the length of the sampling sequence x (N).

The third step is that the FFT module carries out FFT processing on the sampling sequence

The FFT module performs FFT processing on the sample sequence x (n), transforms the sample sequence x (n) from the time domain to the frequency domain, and obtains an FFT processing result x (k):

wherein k is a frequency domain point index value, k is 0,1, …, N-1; j is an imaginary unit, representing

e^‐j2πkn/NExpressed as complex numbers, cos (-2 π kn/N) + jsin (-2 π kn/N).

The fourth step carrier frequency estimation module estimates the carrier frequency according to the FFT processing result

The carrier frequency estimation module screens out the maximum value in the FFT processing result X (k), thereby determining the frequency domain point index value k corresponding to the maximum value₀According to the formula: f. of₀＝k₀/(NT_s) Determining k₀Frequency f corresponding to a point₀。

The fifth step is that the initial phase estimation module estimates the initial phase of the binary phase shift keying signal

The initial phase estimation module estimates the initial phase of the binary phase shift keying signal

Thus, estimation of the initial phase of the binary phase shift keying signal is achieved.

Preferably, the length N of the sampling sequence in the second step is 1024.

Preferably, the initial phase of the binary phase shift keyed signal in the fifth step

Obtained by the following formula:

wherein angle {. cndot } represents the angle of a complex number,

in complex representation form, represent: cos (-4 pi f)₀nT_s)+jsin(‐4πf₀nT_s)。

The method solves the problem of poor estimation performance of the common signal initial phase estimation method. The initial phase of the binary phase shift keying signal can be estimated, the estimated initial phase is high in precision, and the use requirement can be met.

Detailed Description

A method for estimating an initial phase of a binary phase shift keying signal comprises the following specific steps:

first step, an initial phase estimation platform is established

An initial phase estimation stage comprising: the device comprises a signal sampling module, an FFT module, a carrier frequency estimation module and an initial phase estimation module. The following steps:

the signal sampling module has the functions of: sampling the binary phase shift keying signal to form a sampling sequence;

the function of the FFT module is as follows: performing FFT processing on the sampling sequence;

the carrier frequency estimation module has the functions of: estimating carrier frequency according to the FFT processing result;

the initial phase estimation module functions as: an initial phase of the binary phase shift keyed signal is estimated.

The second step signal sampling module samples the binary phase shift keying signal to form a sampling sequence

The signal sampling module samples a binary phase shift keying signal x (t) to form a sampling sequence x (n) with a sampling frequency f_sWith a sampling time interval of T_s，T_s＝1/f_s(ii) a t is a time parameter, N is a time domain point index value, N is 0,1, …, N-1, N is the length of the sample sequence x (N), and N is 1024.

The third step is that the FFT module carries out FFT processing on the sampling sequence

The FFT module performs FFT processing on the sample sequence x (n), transforms the sample sequence x (n) from the time domain to the frequency domain, and obtains an FFT processing result x (k):

wherein k is a frequency domain point index value, k is 0,1, …, N-1; j is an imaginary unit, representing

e^‐j2πkn/NExpressed as complex numbers, cos (-2 π kn/N) + jsin (-2 π kn/N).

The fourth step carrier frequency estimation module estimates the carrier frequency according to the FFT processing result

The carrier frequency estimation module screens out the maximum value in the FFT processing result X (k), thereby determining the frequency domain point index value k corresponding to the maximum value₀According to the formula: f. of₀＝k₀/(NT_s) Determining k₀Frequency f corresponding to a point₀。

The fifth step is that the initial phase estimation module estimates the initial phase of the binary phase shift keying signal

The initial phase estimation module uses the formula:

estimating an initial phase of a binary phase shift keyed signal

Wherein angle {. cndot } represents the angle of a complex number,

in complex representation form, represent: cos (-4 pi f)₀nT_s)+jsin(‐4πf₀nT_s)。

Thus, estimation of the initial phase of the binary phase shift keying signal is achieved.

Claims (1)

1. A binary phase shift keying signal initial phase estimation method is characterized by comprising the following specific steps:

firstly, constructing an initial phase estimation platform of binary phase shift keying signals

A binary phase shift keying signal initial phase estimation stage comprising: the device comprises a signal sampling module, an FFT module, a carrier frequency estimation module and an initial phase estimation module; the following steps:

the signal sampling module has the functions of: sampling the binary phase shift keying signal to form a sampling sequence;

the function of the FFT module is as follows: performing FFT processing on the sampling sequence;

the carrier frequency estimation module has the functions of: estimating carrier frequency according to the FFT processing result;

the initial phase estimation module functions as: estimating an initial phase of the binary phase shift keying signal;

the second step signal sampling module samples the binary phase shift keying signal to form a sampling sequence

The signal sampling module samples a binary phase shift keying signal x (t) to form a sampling sequence x (n) with a sampling frequency f_sWith a sampling time interval of T_s，T_s＝1/f_s(ii) a t is a time parameter, N is a time domain point index value, N is 0,1, …, N-1, and N is the length of the sampling sequence x (N);

the third step is that the FFT module carries out FFT processing on the sampling sequence

The FFT module performs FFT processing on the sample sequence x (n), transforms the sample sequence x (n) from the time domain to the frequency domain, and obtains an FFT processing result x (k):

wherein k is a frequency domain point index value, k is 0,1, …, N-1; j is an imaginary unit, representing

e^-j2πkn/NExpressed in complex number representation, representing cos (-2 π kn/N) + jsin (-2 π kn/N);

the fourth step carrier frequency estimation module estimates the carrier frequency according to the FFT processing result

The carrier frequency estimation module screens out the maximum value in the FFT processing result X (k), thereby determining the frequency domain point index value k corresponding to the maximum value₀According to the formula: f. of₀＝k₀/(NT_s) Determining k₀Frequency f corresponding to a point₀；

The fifth step is that the initial phase estimation module estimates the initial phase of the binary phase shift keying signal

The initial phase estimation module estimates the initial phase of the binary phase shift keying signal

Obtained by the following formula:

wherein angle {. cndot } represents the angle of a complex number,

in complex representation form, represent: cos (-4 pi f)₀nT_s)+jsin(-4πf₀nT_s)

Thus, estimation of the initial phase of the binary phase shift keying signal is achieved.