As one of the key technologies for the fifth generation(5G) wireless networks,device-to-device(D2D) communications allow user equipment(UE) in close proximity to communicate with each other directly.Forwarded by a rel...As one of the key technologies for the fifth generation(5G) wireless networks,device-to-device(D2D) communications allow user equipment(UE) in close proximity to communicate with each other directly.Forwarded by a relay,the relay-aided D2D(RA-D2D) communications can not only be applied to communications in much longer distance but also achieve a high quality of service(Qo S) .In this paper,we first propose a two-layer system model allowing RA-D2 D links to underlay traditional cellular uplinks.Then we maximize the energy efficiency of the RA-D2 D link while satisfying the minimum data-rate of the cellular link.The optimal transmit power at both D2 D transmitter and D2 D relay sides is obtained by transforming the nonlinear fractional programming into a nonlinear parameter programming.Simulation results show that our proposed power allocation method is more energy efficient than the existing works,and the proposed RA-D2 D scheme outperformed direct D2 D scheme when the distance between two D2 D users is longer.展开更多
In order to achieve fast synchronization of the modulation hopping system, a synchronization scheme called short code to guide long code is adopted, and the initial synchronization hops and service hops are designed i...In order to achieve fast synchronization of the modulation hopping system, a synchronization scheme called short code to guide long code is adopted, and the initial synchronization hops and service hops are designed in detail.According to the system requirements for short code in the properties of time-varying, safety and balance, an algorithm to design wide-gap chaos short code based on TOD is proposed.Synchronization performance analysis shows that the algorithm has good performance, the initial synchronization time and the later entering network synchronization time are short, additionally, maximum synchronization time difference and synchronization maintaining time are long, all of which meet the needs of normal communications, and further verify the synchronization scheme feasible.展开更多
Viterbi decoding is widely used in many radio systems. Because of the large computation complexity, it is usually implemented with ASIC chips, FPGA chips, or optimized hardware accelerators. With the rapid development...Viterbi decoding is widely used in many radio systems. Because of the large computation complexity, it is usually implemented with ASIC chips, FPGA chips, or optimized hardware accelerators. With the rapid development of the multicore technology, multicore platforms become a reasonable choice for software radio (SR) systems. The Cell Broadband Engine processor is a state-of-art multi-core processor designed by Sony, Toshiba, and IBM. In this paper, we present a 64-state soft input Viterbi decoder for WiMAX SR Baseband system based on the Cell processor. With one Synergistic Processor Element (SPE) of a Cell Processor running at 3.2GHz, our Viterbi decoder can achieve the throughput up to 30Mb/s to decode the tail-biting convolutional code. The performance demonstrates that the proposed Viterbi decoding implementation is very efficient. Moreover, the Viterbi decoder can be easily integrated to the SR system and can provide a highly integrated SR solution. The optimization methodology in this module design can be extended to other modules on Cell platform.展开更多
The performance of multi-antenna multi-relay cooperative system is investigated in this paper. Two relaying strategies, i.e., reactive and proactive strategies are analyzed with the Amplifyand-Forward (AF) and Decode-...The performance of multi-antenna multi-relay cooperative system is investigated in this paper. Two relaying strategies, i.e., reactive and proactive strategies are analyzed with the Amplifyand-Forward (AF) and Decode-and-Forward (DF) protocols. We derive the Cumulative Distribution Function (CDF) of the received Signal-to-Noise Ratio (SNR) at the destination, which is used to calculate the exact outage probability, for both AF and DF protocols. According to these results, we conclude that a cooperative network which composes K relays each equipped with nr antennas can achieve maximal order-(2nrK+1) diversity gain, by proper processing at relays and destination. Furthermore, the performance comparison is given, in terms of outage probability. These two strategies outperform each other in different scenarios in AF protocol, whilst proactive strategy is always better than its counterpart in DF protocol. According to these results, the optimal power allocation schemes among relay nodes are also presented, with reasonable power constraint.展开更多
This paper lenges in the design of discusses some chal- millimeter-wave （mln- wave） circuits and systems for 5th generation （5G） wireless systems in CMOS process. The properties of some passive and active devices ...This paper lenges in the design of discusses some chal- millimeter-wave （mln- wave） circuits and systems for 5th generation （5G） wireless systems in CMOS process. The properties of some passive and active devices such as inductors, capacitors, transmission lines, translbrmers and transistors in mm-wave frequency band are discussed. Self-healing technique dealing with PVT variation, res- onant mode switching technique to enhance frequency tuning range of voltage controlled oscillator （VCO） and dual mode technique for power amplifier （PA） efficiency enhancement are introduced. At last, A fully-integrated 60 GHz 5 Gb/s QPSK transceiver with the transmit/receive （T/R） switch in 65nm CMOS process is introduced. The measured error vector magnitude （EVM） of the TX is -21.9 dB while the bit error rate （BER） of the RX with a -52 dBm sine-wave input is below 8e-7 when transmitting/receiving 5 Gb/s data. The transceiver is powered by 1.0 V and 1.2 V supply （except the phase-frequency detector and charge-pump in the frequency synthesizer which are powered by 2.5 V supply） and con- sumes 135 mW in TX mode and 176 mW in RX mode.展开更多
基金supported by the ZTE Corp under Grant CON1412150018the Natural Science Foundation of China under Grant 61572389 and 61471361
文摘As one of the key technologies for the fifth generation(5G) wireless networks,device-to-device(D2D) communications allow user equipment(UE) in close proximity to communicate with each other directly.Forwarded by a relay,the relay-aided D2D(RA-D2D) communications can not only be applied to communications in much longer distance but also achieve a high quality of service(Qo S) .In this paper,we first propose a two-layer system model allowing RA-D2 D links to underlay traditional cellular uplinks.Then we maximize the energy efficiency of the RA-D2 D link while satisfying the minimum data-rate of the cellular link.The optimal transmit power at both D2 D transmitter and D2 D relay sides is obtained by transforming the nonlinear fractional programming into a nonlinear parameter programming.Simulation results show that our proposed power allocation method is more energy efficient than the existing works,and the proposed RA-D2 D scheme outperformed direct D2 D scheme when the distance between two D2 D users is longer.
基金supported by the Doctor Sustention Foundation of Telecommunication Engineering Institute,Air Force Engineering University (No.KDYBSJJ08605)the Key Laboratory Foundation of National Defense Science and Technology (No.9140c860302)
文摘In order to achieve fast synchronization of the modulation hopping system, a synchronization scheme called short code to guide long code is adopted, and the initial synchronization hops and service hops are designed in detail.According to the system requirements for short code in the properties of time-varying, safety and balance, an algorithm to design wide-gap chaos short code based on TOD is proposed.Synchronization performance analysis shows that the algorithm has good performance, the initial synchronization time and the later entering network synchronization time are short, additionally, maximum synchronization time difference and synchronization maintaining time are long, all of which meet the needs of normal communications, and further verify the synchronization scheme feasible.
文摘Viterbi decoding is widely used in many radio systems. Because of the large computation complexity, it is usually implemented with ASIC chips, FPGA chips, or optimized hardware accelerators. With the rapid development of the multicore technology, multicore platforms become a reasonable choice for software radio (SR) systems. The Cell Broadband Engine processor is a state-of-art multi-core processor designed by Sony, Toshiba, and IBM. In this paper, we present a 64-state soft input Viterbi decoder for WiMAX SR Baseband system based on the Cell processor. With one Synergistic Processor Element (SPE) of a Cell Processor running at 3.2GHz, our Viterbi decoder can achieve the throughput up to 30Mb/s to decode the tail-biting convolutional code. The performance demonstrates that the proposed Viterbi decoding implementation is very efficient. Moreover, the Viterbi decoder can be easily integrated to the SR system and can provide a highly integrated SR solution. The optimization methodology in this module design can be extended to other modules on Cell platform.
基金supported by the National Natural Science Foundation of China (Grant No. 60932003)the National Hightech R&D Program of China (863 Program, Grant No. 2007AA01Z452, No. 2009AA01Z118)the Shanghai Municipal Natural Science Foundation (Grant No. 09ZR1414900)
文摘The performance of multi-antenna multi-relay cooperative system is investigated in this paper. Two relaying strategies, i.e., reactive and proactive strategies are analyzed with the Amplifyand-Forward (AF) and Decode-and-Forward (DF) protocols. We derive the Cumulative Distribution Function (CDF) of the received Signal-to-Noise Ratio (SNR) at the destination, which is used to calculate the exact outage probability, for both AF and DF protocols. According to these results, we conclude that a cooperative network which composes K relays each equipped with nr antennas can achieve maximal order-(2nrK+1) diversity gain, by proper processing at relays and destination. Furthermore, the performance comparison is given, in terms of outage probability. These two strategies outperform each other in different scenarios in AF protocol, whilst proactive strategy is always better than its counterpart in DF protocol. According to these results, the optimal power allocation schemes among relay nodes are also presented, with reasonable power constraint.
基金supported in part by the National Natural Science Foundation of China under Grant 61331003 and Grant 61222405
文摘This paper lenges in the design of discusses some chal- millimeter-wave （mln- wave） circuits and systems for 5th generation （5G） wireless systems in CMOS process. The properties of some passive and active devices such as inductors, capacitors, transmission lines, translbrmers and transistors in mm-wave frequency band are discussed. Self-healing technique dealing with PVT variation, res- onant mode switching technique to enhance frequency tuning range of voltage controlled oscillator （VCO） and dual mode technique for power amplifier （PA） efficiency enhancement are introduced. At last, A fully-integrated 60 GHz 5 Gb/s QPSK transceiver with the transmit/receive （T/R） switch in 65nm CMOS process is introduced. The measured error vector magnitude （EVM） of the TX is -21.9 dB while the bit error rate （BER） of the RX with a -52 dBm sine-wave input is below 8e-7 when transmitting/receiving 5 Gb/s data. The transceiver is powered by 1.0 V and 1.2 V supply （except the phase-frequency detector and charge-pump in the frequency synthesizer which are powered by 2.5 V supply） and con- sumes 135 mW in TX mode and 176 mW in RX mode.
