Super low bit rate code auxiliary carrier wave synchronization method for deep space communication

A technology of auxiliary carrier and deep space communication, applied in the field of signal receiving technology of deep space communication, can solve the problems of long pilot frequency and small synchronization range, and achieve the effect of low working range and multi-coding gain

Inactive Publication Date: 2016-07-06
UNIV OF ELECTRONICS SCI & TECH OF CHINA
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AI Technical Summary

Problems solved by technology

Usually, the optimal pilot placement method during carrier synchronization is half of the PP structure at the front and back (see figure 2 (a)), but the distance between the two pilots before and after the PP structure is the farthest, and the synchronization range is the smallest

Method used

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  • Super low bit rate code auxiliary carrier wave synchronization method for deep space communication
  • Super low bit rate code auxiliary carrier wave synchronization method for deep space communication
  • Super low bit rate code auxiliary carrier wave synchronization method for deep space communication

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Embodiment Construction

[0022] The signal power is -133dbm. If the signal bandwidth is 1MHz, considering the influence of the RF front-end power amplifier of the received signal, the power spectral density of the background noise is -174dbm, and the signal-to-noise ratio of the receiver is -19dB.

[0023] The pilot frequency is placed in a PMP (pre / mid / postamble) structure, and the EM algorithm is used for fine synchronization. Adopt the systematic LDPC-Hadamard code, its construction process carries on according to step 1. At the receiving end, the receiver first extracts the pilot symbols for a rough compensation; then the decoder iteratively decodes 20 times, and updates the synchronization parameters at each iteration.

[0024] Figure 4 with Figure 5 The root-mean-square curve of the estimated phase deviation of different frequency deviations is given. Image 6 Gives a normalized frequency offset of 1×10 -5 , BER curve for different phase deviations. From Figure 4 It can be seen that the root mea...

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Abstract

The invention relates to a super low bit rate code auxiliary carrier wave synchronization method for deep space communication. According to the method, combination design for a pilot frequency and a super low bit rate code parameter can be carried out at a sending end, coarse synchronization is carried out at a reception end by employing the pilot frequency, the super low bit rate code is further combined to facilitate carrier waves to realize precise synchronization, and thereby large-scale carrier wave synchronization under the super low signal-to-noise ratio is realized. The method is advantaged in that the method works under the super low signal-to-noise ratio, and the carrier wave synchronization scope is large. According to the method, construction of a system, a low bit rate and a short code length LDPC-Hadamard code is mainly illustrated on the basis of the pilot frequency and coding combined auxiliary synchronization algorithm, combination and synchronization of the pilot frequency, the low bit rate and the short code length LDPC-Hadamard code are mainly analyzed, the detailed flow chart is provided, moreover, performance of the method is analyzed.

Description

Technical field [0001] The present invention relates to the signal receiving technology of deep space communication, namely carrier synchronization. Especially in the condition of extremely low signal-to-noise ratio, the design of coding-assisted carrier synchronization. Background technique [0002] Due to the long communication distance of deep space exploration, the signal-to-noise ratio of the received signal is very low due to the influence of free space path loss and noise during the transmission of the signal. At the same time, in order to reduce the bit error rate, a higher redundancy rate is required. , Codewords with better error correction performance can improve performance. However, if the signal-to-noise ratio is too low, the demodulation, decoding, and synchronization of the signal will cause problems. Therefore, the coding-assisted carrier frequency synchronization technology is proposed. The traditional coding-assisted carrier frequency synchronization technolog...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H04L27/26
Inventor 田佳佳史治平张忠培
Owner UNIV OF ELECTRONICS SCI & TECH OF CHINA
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