This letter proposes a robust joint linear precoding scheme based on the minimum mean squared error (MMSE) criterion for amplifyand-forward (AF) multiple-input multiple-output (MIMO) relay broadcast systems with limited feedback, where only the quantized channel direction information (CDI) of the forward channel is available for the base station (BS) and the relay station (RS). The proposed sch...

In this paper, the outage performance is investigated for cognitive dual-hop relay networks with amplify-and-forward (AF) relay and selection combining (SC) receiver at the destination under spectrum sharing constraints on primary user (PU) over independent and identically distributed (i.i.d.) Nakagami-m fading channels. We derive an exact closed-form expression for the outage probability (OP) ...

We consider a relay channel for which the following assumptions are made : 1. The source-destination and relay-destination channels are orthogonal (frequency division relay channel) ; 2. The relay implements the decode-and-forward protocol ; 3. The source and relay implement the same channel encoder namely a convolutional encoder ; 4. They can use arbitrary and possibly different modulations. I...

Cooperative communication has recently become a key technology for modern wireless networks such as 3GPP long-term evolution and WiMAX, because in such networks the transmission rate, the communication reliability, and coverage problems could be improved in a cost-effective manner. This, however, faces many design challenges. First, cooperative transmission typically involves a relaying phase w...

Cooperative networking plays an important role in wireless adhoc and sensor networks, in which the information from the source to the destination is relayed by intermediate nodes. In this paper, we propose OFDM-based all subcarrier and per subcarrier basis relay selection schemes. The relay selection is based on average signal to noise ratio (SNR) estimation. Data aided (DA) preamble based MMSE...

Manuscript Received 8-August-2012 and revised 5-October-2012 ISSN: 2322-3936 Accepted on 1November-2012 Abstract— This paper concerns two-hop communication over relayassisted Block fading channel. It is assumed there is not a direct link between the transmitter and the affiliated destination and the communication occurs in two hops through the use of a relay, where the amplify and forward (AF) ...

Mobile receivers can benefit from an increased spatial diversity through cooperation. Two relaying techniques are typically used : either Amplify and Forward (AF) or Decode and Forward (DF). This contribution presents a new technique which combines the main advantages of both AF and DF. This technique amounts to a DF scheme where all operations are performed in a soft-input soft-output fashion....

Recently, we proposed space-time block coded (STBC) amplify-and-forward (AF) relay for wireless relay communication using unmanned aircrafts (UAs). In STBC-AF relay, UAs perform AF-STBC encoding consisting of conjugate operation and block exchange only. Then, the destination node performs frequency-domain equalization (FDE), diversity combining and linear STBC decoding by using an equivalent ch...

A two-way amplify-and-forward (AF) wireless relay network consisting of 2M sources with only a single antenna per source and one relay with multiple N antennas is studied with a self-interference cancelation process at the 2M destinations in this paper. All sources act as both sources and destinations. The closed form of the relay amplifying matrix is optimized under the relay transmit power co...