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Communication system, sending device, receiving device and digital transmission method

A technology of a transmitting device and a receiving device, which is applied in the field of layered modulation communication systems, can solve problems such as difficulty in improving the quality of the second layer line

Active Publication Date: 2017-11-10
MITSUBISHI ELECTRIC CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, there is a problem that it is difficult to improve the quality of the second layer line

Method used

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  • Communication system, sending device, receiving device and digital transmission method
  • Communication system, sending device, receiving device and digital transmission method
  • Communication system, sending device, receiving device and digital transmission method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment approach 1

[0036] The past layered modulation is briefly explained. figure 1 is a diagram showing the concept of layered modulation. Each layer in layered modulation can be used as an independent circuit. When two streams are multiplexed by hierarchical modulation, each layer is divided into a high-reliability line such as QPSK (first layer), and a low-reliability line such as QAM (such as 16QAM) overlapping with the first layer (second layer) .

[0037] Next, the three parameters of layer ratio, mapping mode, and mapping mode mixing ratio, which are layer parameters used when performing layer modulation in this embodiment, will be described. For simplicity, a case where two lines are overlapped by layered modulation will be described as an example. In addition, a case where QPSK (2 bits) is assigned to the first layer and 16QAM (4 bits) is assigned to the second layer will be described as an example. Hereinafter, this layered mode is referred to as QPSK+16QAM. In this case, the lay...

Embodiment approach 2

[0085] In this embodiment, the layer parameters are determined in the transmission device. Portions different from Embodiment 1 will be described.

[0086] Figure 16 It is a diagram showing a configuration example of a communication system according to the present embodiment. The communication system is composed of a transmitting device 1b and a receiving device 2b. In addition, the transmission device 1b includes: a layered modulation unit 11b that accepts setting of a layered parameter and performs layered modulation; and a layered parameter control unit 12 that determines a layered parameter. In addition, the reception device 2b has a layered demodulation unit 21b that receives layered parameter settings and performs layered demodulation.

[0087] As in Embodiment 1, a system that performs one-to-one digital transmission from the transmitting device 1b to the receiving device 2b is shown as an example of a communication system. It is assumed that two types of transmiss...

Embodiment approach 3

[0097] In this embodiment, layer parameters are determined in the receiving device. Portions different from Embodiments 1 and 2 will be described.

[0098] Figure 17 It is a diagram showing a configuration example of a communication system according to the present embodiment. The communication system is composed of a transmitting device 1c and a receiving device 2c. In addition, the transmission device 1c has a layered modulation unit 11c that receives layered parameter settings and performs layered modulation. The reception device 2c includes a layered demodulation unit 21c that accepts setting of layered parameters and performs layered demodulation, and a layered parameter control unit 22 that determines layered parameters.

[0099] Similar to Embodiments 1 and 2, a system that performs one-to-one digital transmission from the transmitting device 1c to the receiving device 2c is shown as an example of a communication system. It is assumed that two types of transmission ...

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PUM

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Abstract

The invention obtains a communication system capable of flexibly adjusting the quality of each line in layered modulation. This communication system includes: a transmitting device (1a) that performs hierarchical modulation on a plurality of signal sequences and transmits them; a receiving device (2a) that performs hierarchical demodulation on received signals; and a hierarchical parameter setting unit ( 3) It sets layered parameters, the transmitting device (1a) has a layered modulation section (11a) that superimposes signals of a plurality of layers by layered modulation while maintaining the Gray code, and the receiving device (2a) has a halved A layered demodulation unit (21a) detects signals of a plurality of layers by performing layered demodulation on the layer-modulated signal, and a layered parameter setting unit (3) sets a signal power ratio when an upper layer and a lower layer are superimposed. That is, a layering ratio, a mapping mode that allows repeated selection of two modes from among bit-mapped mode candidates, and a mapping mode mixing ratio indicating a ratio of mixing the two mapping modes in a signal sequence are used as layering parameters.

Description

technical field [0001] The present invention relates to a communication system employing layered modulation in which multiple lines are superimposed with multi-valued modulation signals. Background technique [0002] Conventionally, as one of methods for simultaneously transmitting a plurality of data streams having different data priorities and transmission speeds, there is hierarchical modulation in which individually mapped signals are hierarchically superimposed (Non-Patent Document 1 below). Each layer in layered modulation can be used as an independent circuit. In addition, it is assumed that among the layers of hierarchical modulation processed here, the first layer has the highest channel quality (low bit error rate), and the lower layers have lower channel quality (higher bit error rate). [0003] In general, when two streams are multiplexed by hierarchical modulation, each layer is divided into a high-reliability line (first layer) such as QPSK (Quadrature Phase S...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04L27/34
CPCH04L27/3488H04L27/183H04L27/3416
Inventor 西本浩大桥章范
Owner MITSUBISHI ELECTRIC CORP