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—In this paper, receiver designs for orthogonal frequency division multiplexing (OFDM) systems that exploit the Alamouti transmit diversity technique are addressed. In Alamouti space-time coded OFDM systems, the simple Alamouti decoding at the receiver relies on the assumption that the channels do not change over an Alamouti codeword period (two consecutive(More)
Ubiquitous healthcare is the service that offers health-related information and contents to users without any limitations of time and space. Especially, to offer customized services to users, the technology of acquiring context information of users in real time is the most important consideration. In this paper, we researched wearable sensors. We proposed(More)
In this paper, a new bandwidth efficient OFDM transmission scheme is proposed. A bandwidth efficient iterative scheme for OFDM systems without using cyclic prefix was proposed before [3] which works well when a channel does not have a deep spectral null. But such a frequency domain deep null is common in a wireless channel. A bandwidth efficient scheme(More)
When the Alamouti code is applied (as a space-time block code) to an OFDM system with transmit diversity, the simple Alamouti decoding requires that each subchannel is flat-fading and constant over two symbol periods(Alamouti code-word period). The second requirement makes the Alamouti decoding scheme not suitable for time varying channels. In this paper,(More)