MIMO systems transmit signals by multiple antennas at the terminals, thus, to get spatial diversity gain and improve system capacity dramatically. Compared with single MIMO systems, the distributed MIMO system has hig...
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ISBN:
(纸本)9781467390880
MIMO systems transmit signals by multiple antennas at the terminals, thus, to get spatial diversity gain and improve system capacity dramatically. Compared with single MIMO systems, the distributed MIMO system has higher coverage and larger capacity. MIMO systems using the joint coding technique through the full diversity of the space-time code can not only obtain the full diversity gain, but also improve spectrum efficiency effectively. But the detectioncomplexity is high at the receiving terminal and information interference exists when transferring between antennas. Space-time coding can reduce the information interference between antennas and obtain diversity gain without sacrificing the bandwidth. The cyclic delay methods can effectively reduce the detectioncomplexity. We present a high rate of distributed cooperative MIMO transmission scheme combining with space-time coding technique and cyclic delay technology. The transmitting terminal sends message to the relay nodes. Meanwhile, the source through the direct channel broadcasts information to all terminals. After the space-time coding, the received information at relay nodes is sent to the transmitters using cyclic delay method and amplifying forwarding (AF) method. This program applies to scene of both the communication source node and relay nodes all configured with multiple antennas. And the simulation results show that this two-way scheme we proposed can significantly improve the diversity gain and the total transmission rate, and enlarge the coverage of wireless network.
MIMO systems transmit signals by multiple antennas at the terminals, thus, to get spatial diversity gain and improve system capacity dramatically. Compared with single MIMO systems, the distributed MIMO system has hig...
详细信息
MIMO systems transmit signals by multiple antennas at the terminals, thus, to get spatial diversity gain and improve system capacity dramatically. Compared with single MIMO systems, the distributed MIMO system has higher coverage and larger capacity. MIMO systems using the joint coding technique through the full diversity of the space-time code can not only obtain the full diversity gain, but also improve spectrum efficiency effectively. But the detectioncomplexity is high at the receiving terminal and information interference exists when transferring between antennas. Space-time coding can reduce the information interference between antennas and obtain diversity gain without sacrificing the bandwidth. The cyclic delay methods can effectively reduce the detectioncomplexity. We present a high rate of distributed cooperative MIMO transmission scheme combining with space-time coding technique and cyclic delay technology. The transmitting terminal sends message to the relay nodes. Meanwhile, the source through the direct channel broadcasts information to all terminals. After the space-time coding, the received information at relay nodes is sent to the transmitters using cyclic delay method and amplifying forwarding(AF) method. This program applies to scene of both the communication source node and relay nodes all configured with multiple antennas. And the simulation results show that this two-way scheme we proposed can significantly improve the diversity gain and the total transmission rate, and enlarge the coverage of wireless network.
Alamouti code is an excellent option for a two-transmitter and one-receiver network owing to its optimal performance and low detection complexity. Unfortunately, with the requirement of odd number of time slots in the...
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Alamouti code is an excellent option for a two-transmitter and one-receiver network owing to its optimal performance and low detection complexity. Unfortunately, with the requirement of odd number of time slots in the frame structure for data transmission of long-term evolution (LTE)-advanced systems, this scheme is not applicable to such systems. In this correspondence, three new space-time block codes (STBCs) are proposed for LTE-advanced systems with two transmit antennas and a receive antenna with three-time-slots. The proposed designs achieve rate of one symbol per channel use and full transmission diversity. The main objective of designing the first and second codewords is to improve the coding gain of STBCs with three time slots. These STBCs are constructed using real rotation of quadrature amplitude modulation (QAM) information symbols in three dimensions. As will be seen later, the idea of real rotation of transmitted symbols using orthogonal matrices allows a decrease in the number of unknown parameters to be determined in order to maximise the coding gain. Using real rotation to encode the transmitted symbols, a new scheme is obtained which has the same minimum determinant (MD) as Alamouti code for 4, 16 and 64-QAM signal constellations. In designing the last codeword, the authors attempt to reduce the maximum-likelihood decoding complexity by decoupling detection of one encoded symbol from others. The simulation results confirm an improved performance of new schemes as compared to recently proposed codes.
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