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Rateless IoT uplink transmission system and method based on 16QAM

A transmission system and transmission method technology, applied in the field of non-rate IoT uplink transmission system, can solve problems such as high-order modulation technology cannot work effectively, increase IoT node computing power consumption, high modulation and demodulation complexity, etc., to improve transmission. The effect of reliability, reduced bit rate, and good bit error performance

Active Publication Date: 2021-07-20
SOUTH CENTRAL UNIVERSITY FOR NATIONALITIES
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] (1) The low-order modulation technologies such as BPSK and QPSK used by the existing NB-IoT have limited maximum transmission rates, which are only 0.33 and 0.66bits / s / Hz respectively
[0006] (2) The existing rateless TLRCM technology can only effectively reduce the energy consumption of uplink transmission and increase the transmission rate under extremely low channel conditions, but its maximum transmission rate is only 1.6bits / s / Hz, which is difficult to use in larger A higher transmission rate is obtained within the range of channel variation, and the transmitter requires additional modulation operation processing, which increases the computing power consumption of IoT nodes
[0008] (1) The high-order modulation technology has high spectral efficiency and can obtain a high transmission rate, but the traditional high-order modulation technology cannot work effectively under low signal-to-noise ratio
Therefore, how to find a method that high-order modulation can still work effectively under the condition of low signal-to-noise ratio is a challenging work;
[0009] (2) TLRCM uses a larger weight set, such as {±1,±2,±4}, which can increase the transmission rate, but it has high modulation and demodulation complexity, and, TLRCM and existing communication systems The modulation technology is incompatible, and its receiver needs more complex channel estimation and equalization processing, making it difficult to apply to IoT communication
Therefore, how to find a transmission method that can effectively reduce the transmission symbols and obtain a higher rate within a large channel variation range without increasing the calculation amount of IoT nodes, so that it can be applied to applications where computing resources and energy are limited IoT device communication is also a very difficult job

Method used

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  • Rateless IoT uplink transmission system and method based on 16QAM
  • Rateless IoT uplink transmission system and method based on 16QAM
  • Rateless IoT uplink transmission system and method based on 16QAM

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Embodiment 1

[0095] The present invention is achieved in this way, a 16QAM-based Internet of Things uplink rateless coding transmission system, the Internet of Things uplink rateless coding transmission system includes a transmitter and a receiver; the transmitter includes a precoding module, random A bit selection module and a 16QAM symbol mapping module; the receiver includes a receiving control and feedback module and an iterative demodulation-decoding module.

[0096] The precoding module at the sending end is used for source bit stream grouping, CRC check insertion and Turbo coding;

[0097] A random bit selection module for randomly selecting 4 coded bits;

[0098] The 16QAM mapping module is used to map the selected 4 encoded bits into 16QAM symbols, and send symbols in a rateless manner;

[0099] Random 16QAM iterative demodulation-decoding module, used for demodulation and decoding processing at the receiving end;

[0100] The receiving end control and feedback module is used for ...

Embodiment 2

[0126] figure 1 It is a schematic diagram of a 16QAM-based rateless IoT uplink transmission system; in which, the precoding module at the sending end divides the serial data stream into groups, then inserts CRC check digits, and finally performs Turbo coding to obtain coded bits of length N to be transmitted Block b; the random bit selection module randomly selects 4 bits from the coded bit block b each time; the 16QAM mapping module maps the 4 binary bits selected by the random bit selection module to 16QAM communication constellation symbols at a rateless rate These symbols are sent in the same way; the iterative demodulation-decoding module at the receiving end performs data recovery; the control and feedback processing module at the receiving end completes iterative demodulation-decoding scheduling, data error detection and feedback control.

[0127] figure 2 A schematic diagram of bit selection with encoding bit block length N=144 and QAM symbol number M=288 is given. ...

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Abstract

The invention belongs to the technical field of wireless communication, and discloses a rateless IoT uplink transmission system and method based on 16QAM, and a transmitter comprises a precoding module, a random bit selection module and a 16QAM symbol mapping module; the receiver comprises a receiving control and feedback module and an iterative demodulation-decoding module. Through reasonable mapping design, the 16 QAM symbol and the corresponding selected bit automatically meet the weighted sum relation, and continuous transmission energy adjustment can be realized under the condition that the calculated amount of a transmitter is not increased by combining with a rateless transmission technology. Compared with an existing NB-IoT standard using a small weight set TLRCM and BPSK / QPSK low-order modulation, the rateless IoT uplink transmission system based on 16QAM modulation provided by the invention can ensure that IoT nodes of different coverage levels can obtain higher spectrum efficiency and energy efficiency in a wider channel range.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, and in particular relates to a rateless IoT uplink transmission system and method based on 16QAM modulation. Background technique [0002] At present, Internet of Things technology (Internet of Things, IoT) has been widely used in industrial control, intelligent transportation, intelligent agriculture and other fields. However, most IoT communications occur during the uplink data transmission process of IoT nodes. Therefore, how to effectively reduce the uplink transmission energy consumption of IoT nodes is of great significance to IoT applications. In actual IoT application scenarios, IoT nodes are randomly distributed around the base station, and nodes at different locations have different coverage requirements. For example, the 3GPP Narrow Band Internet of Things (NB-IoT) standard provides three types of coverage enhancement (CoverageEnhancement , CE) level - CE0, CE1 and CE2,...

Claims

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Application Information

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IPC IPC(8): H04L1/00H04L1/16H04L27/34
CPCH04L1/0043H04L1/005H04L1/0061H04L1/0081H04L1/1607H04L27/3405
Inventor 饶文贵陈少平代光发王勤
Owner SOUTH CENTRAL UNIVERSITY FOR NATIONALITIES