Kanchan G. Vardhe

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User cooperation, whereby multiple users share their antennas and transmit to a common destination in a collaborative manner, has been shown to be an effective way to achieve spatial diversity. We propose in this paper, a strategy to minimize the total power in a decode-and-forward (DF) multiuser , multi-relay cooperative uplink, such that each user(More)
— In this paper, we propose and compare data sharing schemes and practical receiver designs for cooperative diversity in the cellular uplink. Specifically, we present new multiuser decode and forward (DF) protocols and an amplify and forward (AF) protocol, and we compare their performance in asynchronous uplink environments with low-complexity joint linear(More)
— This paper investigates the impact of inter-user non-orthogonality and asynchronous communication on the information-outage probability performance of multiuser decode-and-forward (DF) cooperative diversity in a code-division multiple-access (CDMA) uplink. Each user in the proposed system transmits its own data towards the base station and also serves as(More)
Most of the prior work on cooperative diversity assumes allocation of orthogonal channels to multiple users (inter-user orthogonality) and synchronous communication between the signals transmitted from different cooperating terminals in the network. Both of these assumptions may require an accurate coordination among the cooperating users causing(More)
—In this paper, we propose a Decode-and-Forward Network Coded (DFNC) multiuser cooperation scheme for orthogonal uplink channels in a wireless network. The network consists of m peers having independent information transmitting to a common destination. Each peer transmits its own data in the first time phase and serves as a relay in the second time phase to(More)
In a recent paper, we proposed a multiuser space-time coded cooperative diversity protocol that operates in an asynchronous code-division multiple-access (CDMA) uplink under non-orthogonal channel assignment. The diversity combining of the relayed information was considered at the base station and the information-outage probability performance was(More)
We present in this paper, multiuser decode-and-forward (DF) sharing scheme and a practical low-complexity adaptive pseudo-linear receiver design for cooperative diversity in an asynchronous cellular uplink. The DF schemes provide near maximum-likelihood (ML) performance, including full diversity and significant throughput improvements over no-sharing and(More)
We analyze the performance of multistage cooperation in decode-and-forward relay networks where the transmission between source and destination takes place in T ≥ 2 equal duration and orthogonal time phases with the help of relays. The source transmits only in the first time phase. All relays that can decode the source's transmission forward the(More)