This paper investigates the performance of cooperative receive diversity, for the wireless body area network (WBAN) radio channel, compliant with the IEEE 802.15.6 Standard, in the case of monitoring a sleeping person. Extensive WBAN measurements near the 2.4 GHz ISM band were used. Up to 7 dB and 20% improvement for two-hop communications with the use of relays are empirically demonstrated wit...

In wireless network transmission, a recently introduced form of spatial diversity, known as user cooperation diversity is an effective way to overcome deep fading. Cooperative users share their antennas and other resources to create a virtual array through distributed transmission and signal processing. In particular, the user cooperation technique is capable of providing sufficient diversity g...

In this study, multi-relay decode-and forward (DAF) cooperative networks employing convolutional coding are studied for asynchronous direct-sequence code-division multiple-access (DS-CDMA) systems over frequency-selective slow fading channels. The authors show that the full benefits of coded cooperative diversity cannot be achieved if no multi-user interference suppression is employed at the co...

Diversity techniques for communications among sensors are very effective tool to increase reception quality and battery lifetimes. A well-known method to increase diversity in cooperative communications is sensor (relay) selection. However, sensor selection method may lead to the selection of the same (near) sensor for transmission over a long period. One of the alternative techniques to sensor...

In a cooperative diversity network users cooperate on transmitting each others’ messages; to some extend nodes therefore collectively act as an antenna array. In this paper we derive upper and lower bounds for the information theoretic capacity of 4 node ad-hoc networks with two transmitters and two receivers using cooperative diversity. For comparison, in an N user channel with M antennas at t...

Sensor networks require robust and efficient communication protocols to maximise the network lifetime. Radio irregularity, channel fading and interference results in larger energy consumption and latency for packet transmission over wireless channel. Cooperative multi-input multi-output (MIMO) schemes can combat the fading effects in wireless sensor network (WSN) and can significantly improve t...

This paper proposes the Ring-TCM coded Amplifyand-Forward (AF) cooperative system, achieving both high spectral efficiency and optimized performance. In a cooperative communication network, individual users are encouraged not only to transmit their own data, but also relay other user’s data. This relaying transmission creates spatial diversity to combat the effect of individual severe fading an...

We construct cooperative diversity coding schemes that mitigate the effects of symbol asynchronicity among network users. We do so by modifying, at the expense of implementation practicality, the signaling complexity of well behaved existing schemes. The modification allows the same good performance (DMT optimality) in the presence of synchronicity, and almost-surely permits full-diversity gain...