8PSK (phase shifting key) planisphere

Abstract

Disclosed is an 8PSK (phase shifting key) planisphere which indicates linear relation between Euclidean distance between constellations and code distance between digital codes. When the Euclidean distance between constellation points is small, code distance between digital codes is small, and the defect that smaller phase shift in a conventional planisphere leads to large number error is avoided. When Euclidean distance between the constellation points is large, code distance between digital codes is large. When Euclidean distance between the constellation points is maximum, code distance between digital codes is the maximum. Random errors on channels are in direct proportion to Euclidean distance between the constellation points, namely, random errors are gradually accumulated to result in changes of digital information. Compared with the prior art, phase change gradually increase on the premise of normal operation of the 8PSK planisphere, and change caused by information distortion of the same degree is accordant with practical information changes on random channels.

Description

technical field [0001] The invention belongs to the technical field of digital phase modulation, and in particular relates to an 8PSK constellation diagram. Background technique [0002] Digital modulation technology, especially digital phase modulation technology (PSK) is the basic technology adopted by large-capacity digital systems. In digital communication, although the theoretical research of PSK has reached a high level, the commercial PSK technology is usually a deformation of BPSK, QPSK or QPSK. The PSK technology that may enter commercial use on a large scale in the next step is 8PSK. [0003] The existing authoritative literature on modulation and demodulation 8PSK model (these literatures and models mainly include 1. Alister Burr’s Modulation and Coding for Wireless Communications, page40; 2. Sergei Semenov and Evgenii Krouk’s Modulation and coding techniques in wireless communications, page47; 3. Fuqin Xiong's Digital Modulation Techniques, second edition. page...

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Problems solved by technology

[0003] The existing authoritative literature on modulation and demodulation 8PSK model (these literatures and models mainly include 1. Alister Burr’s Modulation and Coding for Wireless Communications, page40; 2. Sergei Semenov and Evgenii Krouk’s Modulation and coding techniques in wireless communications, page47; 3. Fuqin Xiong's Digital Modulation Techniques, second edition. page150; 4. Goldsmith's Wireless communications, page136) The relationship between the Euclidean distance and the code distance between constellations has the following disadvantages: 1. Partial Euclidean distance Larger constellation points, the code distance of the digital code represented is the largest, and some are the smallest; and the constellation point with the farthest Euclidean distance, the code distance of the digital code represented is not the largest

2. Greater interference or noise on the channel may cause 1-bit or 3-bit errors in the 3-bit information represented by the 8PSK constellation

In the current error correction code technology, cyclic codes are commonly used to correct 1-bit errors; for error correction technologies greater than or equal to 2-bit errors, BCH codes, convolutional codes or Turbo codes (or LDPC codes that are about to enter commercial use) are usually used. Correction, but at this time the complexity of decoding has increased a lot, resulting in an increase in cost, which is a specific problem that must be faced in product implementation

That is to say, when the Euclidean distance is not the maximum, the corresponding channel error may reach the maximum, resulting in an error that may exceed the error correction capability of the channel code

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