The emergence of massive ultra-reliable and low latency communications (mURLLC) as a category of age/time/reliability-sensitive service over 6G wireless networks has received considerable research attention, which has...The emergence of massive ultra-reliable and low latency communications (mURLLC) as a category of age/time/reliability-sensitive service over 6G wireless networks has received considerable research attention, which has presented unprecedented challenges. As one of the key enablers for 6G,satellite-terrestrial integrated networks (STIN) have been developed to offer more expansive connectivity and comprehensive 3D coverage in space-aerial-terrestrial domains for supporting 6G mission-critical mURLLC applications while fulfilling diverse and rigorous quality of service (QoS) requirements. In the context of these mURLLC-driven satellite services, data freshness assumes paramount importance, as outdated data may engender unpredictable or catastrophic outcomes.To effectively measure data freshness in satellite-terrestrial integrated communications,age of information(AoI)has recently surfaced as a new dimension of QoS metric to support time-sensitive applications. It is crucial to design new analytical models that ensure stringent and diverse QoS metrics bounded by different key parameters,including AoI,delay,and reliability,over 6G satellite-terrestrial integrated networks. However,due to the complicated and dynamic nature of satellite-terrestrial integrated network environments, the research on efficiently defining new statistical QoS provisioning schemes while taking into account varying degrees of freedom has still been in their infancy. To remedy these deficiencies, in this paper we develop statistical QoS provisioning schemes over 6G satellite-terrestrial integrated networks in the finite blocklength regime. Particularly, we firstly introduce and review key technologies for supporting mURLLC.Secondly,we formulate a number of novel fundamental statistical-QoS metrics in the finite blocklength regime.Finally,we conduct a set of simulations to validate and evaluate our developed statistical QoS provisioning schemes over satellite-terrestrial integrated networks.展开更多
Bit-interleaved coded modulation (BICM) is suitable to bandwidth-efficient communication systems. Hybrid automatic repeat request (HARQ) can provide more reliability to high-speed wireless data transmission. A new pat...Bit-interleaved coded modulation (BICM) is suitable to bandwidth-efficient communication systems. Hybrid automatic repeat request (HARQ) can provide more reliability to high-speed wireless data transmission. A new path weight complementary convolutional (PWCC) code used in the type-Ⅱ BICM-HARQ system is proposed. The PWCC code is composed of the original code and the complimentary code. The path in trellis with large hamming weight of the complimentary code is designed to compensate for the path in trellis with small hamming weight of the original code. Hence, both of the original code and the complimentary code can achieve the performance of the good code criterion of corresponding code rate. The throughput efficiency of the BICM-HARQ system wit PWCC code is higher than repeat code system, a little higher than puncture code system in low signal-to-noise ratio (SNR) values and much higher than puncture code system, the same as repeat code system in high SNR values. These results are confirmed by the simulation.展开更多
Energy efficiency (EE) can be enhanced by retransmissions and combining in hybrid automatic repeat request (HARQ) system. However, it is difficult to optimize the transmit power of each retransmission when the acc...Energy efficiency (EE) can be enhanced by retransmissions and combining in hybrid automatic repeat request (HARQ) system. However, it is difficult to optimize the transmit power of each retransmission when the accurate retransmission number and future channel state information (CSI) cannot be obtained. This paper proposes a simple energy efficient HARQ scheme for point-to-point wireless communication. In the proposed scheme, the conditional word error rate (WER) of each retransmission is fixed and the transmit power is adapted correspondingly. Three performance metrics are analyzed including average transmission number, throughput and EE. Compared with the conventional equal power HARQ scheme, the proposed scheme can significantly improve the EE and other two metrics under the same constraint of average transmit power or average energy consumption. Furthermore, it is found that, selecting a conditional WER which is slightly smaller than the optimal one is sufficient for practical implementation.展开更多
The flexibility of the media access control(MAC) layer has always been an important concern in the existing communication architecture. To meet the more stringent requirements under large-scale connections, the MAC la...The flexibility of the media access control(MAC) layer has always been an important concern in the existing communication architecture. To meet the more stringent requirements under large-scale connections, the MAC layer structure needs to be optimized carefully. This paper proposes a new architecture of the MAC layer to optimize the complex communication backhaul link structure, which will increase the flexibility of the system and decrease the transmission delay. Moreover, an adaptive transmission time interval(TTI) bundling with self-healing scheme is proposed to further decrease the transmission delay and improve the quality of service(QoS). The simulation results show that the average transmission delay is greatly reduced with our proposed scheme. The bit error rate(BER) and the block error rate are also improved even if the channel changes drastically.展开更多
In this paper,we propose a transmission scheme for uplink and downlink transmissions,where the fifth generation(5G)low-density parity-check(LDPC)codes are implemented for error correction.In the proposed scheme,the ac...In this paper,we propose a transmission scheme for uplink and downlink transmissions,where the fifth generation(5G)low-density parity-check(LDPC)codes are implemented for error correction.In the proposed scheme,the acknowledgment(ACK)or negative acknowledgment(NACK)feedback information is transmitted along with the payload data by cyclically shifting coded sequence,while the re-transmitted codewords are superimposed(XORed)partially on the current codewords.The distinguished feature of the proposed transmission scheme is that it requires neither extra transmission bandwidth nor extra transmission power.We also propose to truncate the error patterns for the purpose of reducing the implementation complexity and reducing the error propagation.Numerical results show that the proposed scheme significantly outperforms conventional LDPC-coded transmission.For the 5G LDPC code with length 1920 at the signal-to-noise ratio(SNR)of 1.3 dB,the word error rate(WER)of the data transmitted by the proposed scheme is about 10^(−4),while that of the conventional LDPC-coded transmission is about 10^(−2).展开更多
基金supported by the Key Area Research and Development Program of Guangdong Province under Grant 2020B0101110003in part by the National Natural Science Foundation of China under Grant 62341132+2 种基金the National Key Research and Development Program of China under Grant 2021YFC3002102the Key Research and Development Plan of Shaanxi Province under Grant 2022ZDLGY05-09the Natural Science Basic Research Program of Shaanxi under Grant 2024JC-YBQN-0642.
文摘The emergence of massive ultra-reliable and low latency communications (mURLLC) as a category of age/time/reliability-sensitive service over 6G wireless networks has received considerable research attention, which has presented unprecedented challenges. As one of the key enablers for 6G,satellite-terrestrial integrated networks (STIN) have been developed to offer more expansive connectivity and comprehensive 3D coverage in space-aerial-terrestrial domains for supporting 6G mission-critical mURLLC applications while fulfilling diverse and rigorous quality of service (QoS) requirements. In the context of these mURLLC-driven satellite services, data freshness assumes paramount importance, as outdated data may engender unpredictable or catastrophic outcomes.To effectively measure data freshness in satellite-terrestrial integrated communications,age of information(AoI)has recently surfaced as a new dimension of QoS metric to support time-sensitive applications. It is crucial to design new analytical models that ensure stringent and diverse QoS metrics bounded by different key parameters,including AoI,delay,and reliability,over 6G satellite-terrestrial integrated networks. However,due to the complicated and dynamic nature of satellite-terrestrial integrated network environments, the research on efficiently defining new statistical QoS provisioning schemes while taking into account varying degrees of freedom has still been in their infancy. To remedy these deficiencies, in this paper we develop statistical QoS provisioning schemes over 6G satellite-terrestrial integrated networks in the finite blocklength regime. Particularly, we firstly introduce and review key technologies for supporting mURLLC.Secondly,we formulate a number of novel fundamental statistical-QoS metrics in the finite blocklength regime.Finally,we conduct a set of simulations to validate and evaluate our developed statistical QoS provisioning schemes over satellite-terrestrial integrated networks.
基金the National Natural Science Foundation of China(Nos. 60302006 and 60462002)
文摘Bit-interleaved coded modulation (BICM) is suitable to bandwidth-efficient communication systems. Hybrid automatic repeat request (HARQ) can provide more reliability to high-speed wireless data transmission. A new path weight complementary convolutional (PWCC) code used in the type-Ⅱ BICM-HARQ system is proposed. The PWCC code is composed of the original code and the complimentary code. The path in trellis with large hamming weight of the complimentary code is designed to compensate for the path in trellis with small hamming weight of the original code. Hence, both of the original code and the complimentary code can achieve the performance of the good code criterion of corresponding code rate. The throughput efficiency of the BICM-HARQ system wit PWCC code is higher than repeat code system, a little higher than puncture code system in low signal-to-noise ratio (SNR) values and much higher than puncture code system, the same as repeat code system in high SNR values. These results are confirmed by the simulation.
基金supported by National Natural Science Foundation of China (61072059)
文摘Energy efficiency (EE) can be enhanced by retransmissions and combining in hybrid automatic repeat request (HARQ) system. However, it is difficult to optimize the transmit power of each retransmission when the accurate retransmission number and future channel state information (CSI) cannot be obtained. This paper proposes a simple energy efficient HARQ scheme for point-to-point wireless communication. In the proposed scheme, the conditional word error rate (WER) of each retransmission is fixed and the transmit power is adapted correspondingly. Three performance metrics are analyzed including average transmission number, throughput and EE. Compared with the conventional equal power HARQ scheme, the proposed scheme can significantly improve the EE and other two metrics under the same constraint of average transmit power or average energy consumption. Furthermore, it is found that, selecting a conditional WER which is slightly smaller than the optimal one is sufficient for practical implementation.
文摘The flexibility of the media access control(MAC) layer has always been an important concern in the existing communication architecture. To meet the more stringent requirements under large-scale connections, the MAC layer structure needs to be optimized carefully. This paper proposes a new architecture of the MAC layer to optimize the complex communication backhaul link structure, which will increase the flexibility of the system and decrease the transmission delay. Moreover, an adaptive transmission time interval(TTI) bundling with self-healing scheme is proposed to further decrease the transmission delay and improve the quality of service(QoS). The simulation results show that the average transmission delay is greatly reduced with our proposed scheme. The bit error rate(BER) and the block error rate are also improved even if the channel changes drastically.
基金supported by National Key R&D Program of China(No.2020YFB1807100)the National Natural Science Foundation of China(No.61971454).
文摘In this paper,we propose a transmission scheme for uplink and downlink transmissions,where the fifth generation(5G)low-density parity-check(LDPC)codes are implemented for error correction.In the proposed scheme,the acknowledgment(ACK)or negative acknowledgment(NACK)feedback information is transmitted along with the payload data by cyclically shifting coded sequence,while the re-transmitted codewords are superimposed(XORed)partially on the current codewords.The distinguished feature of the proposed transmission scheme is that it requires neither extra transmission bandwidth nor extra transmission power.We also propose to truncate the error patterns for the purpose of reducing the implementation complexity and reducing the error propagation.Numerical results show that the proposed scheme significantly outperforms conventional LDPC-coded transmission.For the 5G LDPC code with length 1920 at the signal-to-noise ratio(SNR)of 1.3 dB,the word error rate(WER)of the data transmitted by the proposed scheme is about 10^(−4),while that of the conventional LDPC-coded transmission is about 10^(−2).