Recently Li and Xia have proposed a transmission scheme for wireless relay networks based on the Alamouti space time code and orthogonal frequency division multiplexing to combat the effect of timing errors at the relay nodes. This transmission scheme is amazingly simple and achieves a diversity order of two for any number of relays. Motivated by its simplicity, this scheme is extended to a mor...

Multipath fading is inherent in wireless communication systems. Diversity is the technique which takes advantage of multipath to mitigate the effect of fading and increase signal strength. Space Time Block codes (STBC) are used in MIMO systems to improve the performance by maximizing transmit and/or receive diversity. Among different schemes based on STBC, Quasi Orthogonal Space Time Block Code...

Several interference cancellation (IC) schemes have been recently proposed to suppress multi-user interference for various network configurations (e.g., multiple access and X channels). However, most of these schemes trade-off diversity for implementation complexity or vice-versa. In this paper, we propose a full-diversity interference cancellation scheme in a multiple-input multiple-output (MI...

In the recent years, multiple-input multiple-out (MIMO) technology has attracted lots of attention because it significantly increases the data throughput (multiplexing gain) and link reliability (diversity gain) without additional bandwidth or transmission power. Orthogonal frequency division multiplexing (OFDM) technology has been developed into a popular scheme for wideband digital communicat...

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...

The combination of the orthogonal frequency-division multiplexing (OFDM) technique and the multiple-input multiple-output (MIMO) architecture has emerged as a promising candidate for future wireless communications. The Space-time block coding (STBC) technique permits to fully take advantage of MIMO-OFDM systems and to effectively improve the channel capacity and the spatial diversity. The Golde...

In this paper we derive the optimal diversity versus multiplexing tradeoff for a frequency selective i.i.d. Rayleigh MIMO channel. This tradeoff is shown to be better than the one of the frequency flat MIMO channel. Traditional approaches for frequency selective channels use OFDM techniques in order to exploit the diversity gain due to frequency selectivity. We show that although coding in OFDM...

A prospective study examined the role of identity negotiation processes in determining the impact of diversity on the performance of small groups of MBA students. When group members (N = 253) formed relatively positive impressions of one another, higher diversity encouraged participants to individuate other group members, which encouraged self-verification processes, which in turn enhanced perf...

In this paper, we study the performance of two important types of decode–and–forward (DF) relaying schemes proposed for cooperative diversity (CD) systems, namely, cooperative maximum–ratio combining (C–MRC) and link adaptive regeneration (LAR). In particular, we provide a unified framework for the error rate performance analysis of C–MRC, LAR–αinst, and LAR–α DF schemes for multi–branch CD sys...

In this note, we propose a full-duplex decode-and-forward cooperative diversity scheme based on code division with orthogonal complementary codes. We consider a simple case in which a single user is assisted by a single relay to achieve cooperative diversity. When the cooperation is full-duplex, the operational delay of the relay makes the channel asynchronous and this may cause multiple-access...