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Continuous phase qpsk modulation method and modulation device

A phase control word and phase technology, applied in the field of modulation, can solve the problems of high complexity, low complexity, and sudden phase change of CPM modulation mode, and achieve the effects of simple structure, low complexity and low cost

Active Publication Date: 2017-02-08
UNIV OF ELECTRONICS SCI & TECH OF CHINA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The object of the present invention is to overcome the problem of the phase mutation that exists in the PSK modulation mode existing in the prior art and the relatively high deficiency that the CPM modulation mode realizes complexity, provide a kind of continuous phase QPSK modulation method and its modulation device, the modulation The method can overcome the disadvantage of strong spectrum visibility of the signal waveform caused by the phase jump in the PSK modulation mode, and the device for realizing the modulation method has a simple structure and low complexity

Method used

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  • Continuous phase qpsk modulation method and modulation device
  • Continuous phase qpsk modulation method and modulation device
  • Continuous phase qpsk modulation method and modulation device

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Embodiment 1

[0048] like figure 1 As shown, the continuous phase QPSK modulation device of the present invention includes a data change detector 101, a frequency selector 104, a carrier phase control word generator 105, an additional accumulation phase control word generator 103, a gate 102, and a phase control word calculator 106 , phase control word accumulator 107 and ROM lookup table 108, where,

[0049] The data change detector 101 is used to detect whether the data sent by the current clock is the same as the data sent by the adjacent previous clock. If the data change detector detects that the data sent by the current clock is the same as the data sent by the adjacent previous clock, it outputs Signal "00", if the transmitted data is different, output different signals according to the phase difference between adjacent transmitted data waveforms: if the phase difference value is π / 2 or - 3π / 2, output signal "01"; if the phase difference value is ±π, the output signal is "10"; if th...

Embodiment 2

[0058] It should be noted that K represents the depth of the ROM look-up table, that is, the upper limit value of the ROM look-up table address.

[0059] It should be noted that, in this embodiment, M represents: the additional accumulated phase reaches π / 2 after M clock cycles, and M also represents the basic length of the transition waveform. When the phase difference is π / 2 or -3π / 2, the transition waveform and the modulation waveform of the current data are smoothly connected after M clock cycles; when the phase difference is ±π, the transition waveform and the current data modulation waveform after 2×M clock cycles The modulation waveform of the current data is smoothly connected; when the phase difference is 3π / 2 or -π / 2, the transition waveform and the modulation waveform of the current data are smoothly connected after 3×M clock cycles.

[0060] M1 can also be used to represent the basic length of the transition waveform, that is, the additional accumulated phase reach...

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Abstract

The invention discloses a continuous phase QPSK (quadrature phase shift keying) modulation device. The continuous phase QPSK modulation device comprises a data change detector, a frequency selector, a carrier phase control word generator, an additional accumulated phase control word generator, a noise gate, a phase control word calculator, a phase control word accumulator and an ROM (read only memory) lookup table. The continuous phase QPSK modulation device is simple in structure and easy to implement. The invention further discloses a continuous phase QPSK modulation method. In the continuous phase QPSK modulation method, continuity of modulation waveforms is realized by smoothly transiting continuous transitional waveforms of a data waveform phase to the modulation waveforms of the current data, phase jump existing in the modulation waveforms of transmitted data before and after adjacent clocks is eliminated, and accordingly, pulse response caused by jumping phases is eliminated, symbol rate information contained in waveform signals is hidden, and communication safety and confidentiality are improved.

Description

technical field [0001] The present invention relates to a modulation method, in particular to a continuous phase quadrature phase shift keying (Quadrature Phase Shift Keying, QPSK for short) modulation method. Background technique [0002] Phase Shift Keying (PSK for short) is a modulation technique that uses the phase of the carrier to represent the information of the input signal, that is, the phase change is used to transmit digital information. Binary Phase Shift Keying (BPSK), Quadri Phase Shift Keying (QPSK) and Offset Quadrature Phase Shift Keying used in IS-95 and IMT-2000 (Offset QPSK, referred to as OQPSK) and so on belong to phase shift keying modulation. [0003] When the phase shift keying technique is used for signal modulation, the phase change is sudden. In QPSK, the transmitted carrier signal has 4 possible phase values, which can be expressed as ,in is the initial phase value, and . Therefore, when the transmitted data changes, the carrier phase di...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/20
Inventor 吴廷勇周将运朱文翰曹灵吉胡剑浩李少谦
Owner UNIV OF ELECTRONICS SCI & TECH OF CHINA
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