Wenxun Qiu

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—Carrier frequency offset (CFO) causes spectrum misalignment of transmitter and receiver filters. This misalign-ment leads to energy loss and distortion of received signal, resulting in performance degradation of the whole system. However, these issues are often overlooked by existing works. This paper presents an exact signal model for OFDM that takes into(More)
— Diversity exploitation is a proven efficient means for addressing detrimental effects of wireless channel fadings. User channelization, where the frequency and time resources are structured into several user channels, can substantially help to capture the diversity, but it has not been well investigated. In this paper, we develop theoretical formulation(More)
—Traditional communication systems adopt either time division duplexing (TDD) or frequency division duplexing (FDD). TDD requires guard interval and FDD needs guard band. Orthogonal multicarrier division duplexing (MDD) is a new duplexing scheme, which can avoid both guard interval and guard band. In this paper, we propose a new MDD scheme with a group-wise(More)
The traditional diagnosis of sleep apnea and hypopnea syndrome (SAHS) requires an expensive and complex overnight procedure called polysomnography (PSG). Recently, finding valid alternatives for SAHS diagnosis has attracted much research attention. This paper focuses on the real-time monitoring and detection of SAHS based on the arterial oxygen saturation(More)
—We develop new transmission schemes for multipoint-to-multipoint (M2M) networks which, unlike the existing approaches, address duplexing/multiplexing and multiple access jointly and possess true M2M characteristics in the physical layer. In the proposed schemes, all forward and reverse links of the M2M network share the overall spectrum concurrently in an(More)
—Interference control is crucial in cognitive radio networks and the existing related works focus on quasi-static channels. The expansion of wireless services and applications in everyday life has necessitated support of higher mobility, as evident from the emerging wireless standards. This results in time-varying fading channels within a transmission frame(More)
—Modern wireless communication systems are designed to operate in diverse propagation conditions. Adap-tive transmission techniques are powerful tools for achieving this objective. We propose a new adaptive transmission method for fast fading channels. The new method combines benefits of closed loop and open loop transmission techniques by efficient(More)
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