Underwater Acoustic (UWC) Communication techniques are an interesting area of communication research, in which achieving high data rate, low latency and high throughput is challenging task. In this paper, we used the OFDM multicarrier modulation technique which is suitable for underwater acoustic communication for highly limited bandwidth to enhance the data rate at the receiver. We used effici...

In OFDM-based IEEE 802.11 Wireless LANs, adapting the modulation type per sub-carrier to the frequency selectivity of the wireless channel leads to significant performance improvements. To integrate adaptive modulation into IEEE 802.11a/g networks, some minor modifications to the standard are needed in order to acquire the subcarrier gains and signalize the modulation assignments (on a per-pack...

The motivation for adaptive modulation and coding is to adjust the method of transmission to ensure that the maximum efficiency is achieved over the link at all times. The receiver estimates the channel quality and reports it back to the transmitter. The transmitter then maps the reported quality into a link mode. This mapping however, is not a one-to-one mapping. In this paper we investigate a...

This paper investigates adaptive bit-interleaved coded modulation (BICM) with different iterative decoding schemes for bandwidth efficient transmission. We assume knowledge of the average channel quality at the transmitter. For a fixed modulation scheme, the bandwidth efficiency can be adapted to the channel quality by changing the channel code rate and the iterative decoding procedure can be o...

We propose an adaptive modulation scheme for wireless MIMO systems. The main goal of this scheme is to maximize the bit rate for a fixed target BER. The MIMO channel is split up into several independent channels (subspaces) by a singular value decomposition. On each of these independent channels the modulation format is adapted to the subchannel SNR. The proposed algorithm allocates appropriate...

In this paper, we propose an orthogonal frequency division multiplexing–based (OFDMbased) underwater acoustic multimedia system. An essential feature of this system is that it offers greater power and schemes with significant error protection for the transmission of sensor data information requiring a higher quality of service (QoS). To realize maximum resource utilization or minimum total tran...

Atherosclerosis is a complex inflammatory disorder of the medium and large-sized arteries. Recent experiments demonstrated that atherosclerosis is a Th1 dominant autoimmune condition, whereas Th2 cells are rarely detected within the atherosclerotic lesions. Several studies have indicated that Th2 type cytokines could be effective in the reduction and stabilization of atherosclerotic plaque. The...

In this paper we describe and analyze a simple but effective algorithm for selecting transmit antennas and their coding-modulation schemes in multiple input multiple output (MIMO) communication systems. The algorithm selects the most suitable antennas among those available at the transmitter by observing the signal to selfgenerated noise ratio obtained, applying pseudoinverse on the MIMO channe...

Multiple-input multiple-output (MIMO) eigenbeam space division multiplexing that uses adaptive modulations for substreams is a promising technology for improving transmission capacity. A fundamental drawback of this approach is that the modulation levels determined from the carrier-to-noise ratio at each substream are sometimes overly optimistic so the use of these modulation levels results in ...