Cooperative communication can effectively mitigate the effects of multipath propagation fading by using relay channels to provide spatial diversity. A relaying scheme suitable for half-duplex devices is the quantize-and-forward (QF) protocol, in …
Several diversity techniques have been proposed to cope with fading in wireless networks. A recent and promising technique, which does not increase hardware demands, is cooperative communication. Here spatial diversity is created by using other …
In traditional multicarrier systems, the pilot carriers used to estimate the channel are placed as uniform as possible over the bandwidth. However, with the raise of cognitive radio systems, where the multicarrier system is used by the secondary …
In traditional multicarrier systems, the pilot carriers used to estimate the channel are placed as uniform as possible over the bandwidth. However, with the raise of cognitive radio systems, where the multicarrier system is used by the secondary …
In this contribution, we present a novel accurate closed-form approximation for the bit error rate (BER) of orthogonal space-time block codes (OSTBCs) employing quadrature amplitude modulation with Gray-mapping on spatially correlated Rayleigh fading …
Unique-word (UW) OFDM is a new multicarrier technique that was recently proposed in [M. Huemer, C. Hofbauer, and J. B. Huber, "The Potential of Unique Words in OFDM, Proc. InOWo, Hamburg, Germany, Sep. 2010, pp. 140-144]. In this technique, the guard …
We propose an iterative decision-directed joint frequency offset (FO) and channel estimation algorithm in a known symbol padding (KSP) orthogonal frequency division multiplexing (OFDM) system, where the guard interval is filled with pilot symbols. …
Cooperative communication systems can effectively be used to combat fading. A cooperative protocol that can be used with half-duplex terminals is the Quantize and Forward (QF) protocol, in which the relay quantizes the information received from the …
An analysis of the exact bit error rate (BER) performance of orthogonal space-time block codes (OSTBCs) with maximum-likelihood detection in the presence of channel estimation errors is presented. The possibly correlated coefficients of the …
Multiple-input multiple-output (MIMO) systems employing adaptive modulation have been widely used for their potential to optimize the spectral efficiency while keeping the bit error probability (BEP) under a certain target level. In this paper, we …