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This paper considers a multi-input multi-output (MIMO) wireless relay network, where the source S communicates wirelessly to the destination D via the help of a nonregenerative relay R. Previous studies are almost exclusively based on the assumptions of equal time-duration phases for S-R and R-D transmission and equal number of multiple antennas for every node, and the results concerning arbitrary...
This paper proposes an efficient method for optimal joint precoding-postcoding design in a multi-input multi-output (MIMO) multi-sensor noisy observation context — a problem that is of great interest to the multi-relay MIMO transmission system. A set of wireless sensors, each provisioned with a different number of antennas and a different power constraint, precode and send their noisy observations...
The promising projects of satellite swarm have been studied by scientists from NASA, ESA and other institutes around the world. With a massive number of pico-class, low-power and low-weight space-crafts like pico-satellites, nano-satellites, Swarm can exploring outer space environment or taking other tasks that are hard to be fulfilled by common satellites. The other merit of using swarm than common...
This paper investigates the general achievable rate region (ARR) for a wireless multi-way relay (MWR) network with full message exchange and decode-and-forward (DF) cooperative strategy. The MWR network consists of K users, each equipped with M antennas, and a single relay equipped with N antennas; and there is no user-user direct connectivity. Since different schedules would result in different ARRs,...
We consider the relaying of binary antipodal signals across two hops via soft regeneration and soft error protection. The signals at the input of the regenerator are degraded by additive white Gaussian noise (AWGN). Traditional approaches either directly relay the noisy analog waveform to the destination (thus missing the opportunity for coding gain), or make hard detection and then re-encode the...
This paper considers wireless sensor networks with limited bandwidth, where sensors must transmit sensing results that are distorted with noise uncertainty, to the fusion center reliably and efficiently. A class of rate-1 linear complex-field coding (CFC) transmission strategy is developed, to effectively protect the noisy observation of the signals without any bandwidth expansion. Pairwise error...
An over-booking based dynamic spectrum management (DSM) scheme is conceived for improving the attainable spectral efficiency. All secondary users (SU) will be categorized into different classes and they borrow spectral resource from the primary users (PU) before data transmission. Under the risk-based policy model, the effects of both booking cancellations and 'no-show' reservations are analyzed....
This paper introduces an infusion monitoring system, aiming to reduce potential safety hazard of manually-controlled infusion. Dripping speed and height of the liquid level serving as monitoring signal, all data is collected by infrared as well as laser sensors. Information will then be sent to terminal monitoring interface via wireless transmission module. When the drop appears too fast or height...
This paper devises a novel group frequency-hopping (FH) scheme for OFDM modulated multiuser system, in order to optimize the resource reuse efficiency and resolve the performance degradation due to the deep fading in the same time. In the OFDM modulated multiuser system, the traditional FH schemes can work in a multipath fading environment and achieve a moderate bit-error-rate (BER). However, when...
This article established a double antennas positioning method and system model. Considering the impact of white Gaussian noise, SNR difference and time difference of arrival of dual-antenna can be calculated at the receiving end to make equations in multi-path fading channel. In the space of two-dimensional the wave source location can be expressed as the function of SNR difference and time difference.
In the field of modern wireless communication, there are mainly some technologies that provide solutions to the wireless data transmission network, such as: GSM, CDMA, 3G, Wi-Fi. These solutions make network work with high efficiency and good quality, but still with high cost. So it was difficulty in popularizing in with low cost and at the circumstance of infrastructureless or infrastructure destruction...
Cooperative diversity is an emerging technique that enables single-antenna terminals to share their resources (bandwidth and power) and achieve transmit diversity in a distributed fashion. In this work, an adaptive decode-and-forward(DF) cooperative diversity system based on quadrature signaling is proposed. Then a tight closed-form approximate bit error rate(BER) expression is derived in terms of...
WiMAX security has two goals, one is to provide privacy across the wireless network and the other is to provide access control to the network. The security sublayer of IEEE 802.16 employs an authenticated client/server key management protocol in which the BS, the server, controls the distribution of keying material to the client SS. This paper analyzes the physical layer threat and MAC layer threat...
In this paper, a novel differential dual frequency antenna for wireless communication using proximity coupling technique is presented. Dual bands are realized by 6 meandering slits at the patch's non-radiating edges. The slot in the ground plane is employed to improve the performance of the antenna. The parameter study is also performed in order to investigate the characteristics of the proposed antenna...
Cooperative diversity enables single-antenna terminals in a multi-user environment to share their antennas so as to form a virtual antenna array and achieve spatial diversity in a distributed fashion. To improve the bandwidth efficiency of classical scheme, a novel cooperative diversity scheme based on space-time coding is proposed in this work. With the selection decode-and-forward (SDF) relaying...
Two differential dual-frequency antennas for wireless communication are demonstrated in this paper. In the proposed antennas, electromagnetic energy is magnetically coupled from the feed line to the antenna through the slot in the ground plane. Simulation results show that the impedance bandwidths meet the bandwidth requirement for wireless communication. Meanwhile, good radiation performances are...
In this paper, an adaptive cooperative diversity system based on quadrature signaling is proposed. With the decode-and-forward (DF) relaying protocol, a tight closed-form approximate bit error rate (BER) for binary phase shift keying (BPSK) constellation modulation is derived, and the effect of inter-user channel quality and power scale factor on system performance is investigated. Theoretical and...
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