An ultra-simplified spwm modulation system based on square wave beats in qpsk communication
A modulation system, square wave technology, applied in the field of ultra-simplified SPWM modulation system, can solve the problems of large analog circuit part area, unable to meet the design requirements of underwater communication nodes, etc.
Inactive Publication Date: 2020-10-13
WUHAN UNIV
View PDF3 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
The classic SPWM waveform realization system generally adopts the method of comparing the sending signal with a triangular carrier, and the area of the analog circuit is relatively large, which cannot meet the design requirements of underwater communication nodes
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0033] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.
[0034] The QPSK time domain signal can be expressed as:
[0035] the s QPSK (t)=I(t)cos(2πf c t)-Q(t)sin(2πf c t)
[0036] Among them, f c is the QPSK carrier frequency, I(t) is the same-direction branch signal, Q(t) is the quadrature branch signal, and the QPSK modulation principle is as follows figure 1 shown. I(t)∈{1,-1}, Q(t)∈{1,-1}. For different I and Q combination values, the QPSK time-domain signal can be rewritten as the form of the same frequency and different phases. The QPSK constellation diagram is as follows figure 2 Shown:
[0037]
[0038] The classic SPWM modulation method is to intercept the transmitted signal through a triangular wave of a certain frequency to form SPWM pulses with different duty ratios. The theoretical basis is the sampling control theory: when narrow pulses with equal impulse and different shap...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention provides a square wave beat based super-simplified SPWM modulation system in QPSK communication. The system of the invention comprises a square wave beat based novel SPWM modulation algorithm for QPSK communication and a DSP based super-simplified SPWM digital realization system. An underwater communication node is a key terminal node for the marine environment monitoring and defensesecurity investigation, and the characteristics thereof determine that low power consumption and small volume of equipment should be considered during the design of the underwater node. In an underwater acoustic communication transmission system, a transmission signal is transmitted by an underwater acoustic transducer under the drive of an SPWM modulation circuit and a power amplifier circuit, and this part contains numerous analog modules. The invention focuses on a signal transmitting end of the communication node and the characteristics of a QPSK modulation signal, makes improvement for the traditional SPWM generating principle and generating circuit, and proposes a square wave beat based SPWM modulation algorithm in the QPSK modulation system and a DSP based super-simplified SPWM digital modulation system, thereby reducing the analog circuit area and power consumption to meet the needs of the underwater communication node.
Description
technical field [0001] The invention relates to the field of communication modulation algorithms, and relates to a method and method for generating SPWM waves required by a power amplification system in a QPSK modulation system, in particular to an ultra-simplified SPWM modulation system based on square wave beats in QPSK communication. Background technique [0002] The high-speed underwater acoustic communication of underwater communication nodes widely adopts the QPSK communication standard for information transmission, and its concealment, high performance and other requirements determine that low power consumption and small size must be considered factors in node design. The classic SPWM waveform implementation system generally adopts the method of comparing the transmitted signal with a triangular carrier, and the analog circuit part has a large area, which cannot meet the design requirements of underwater communication nodes. Contents of the invention [0003] Aiming...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/20H04B14/02
CPCH04B14/026H04L27/20
Inventor 江鹏韩震张宇
Owner WUHAN UNIV