This paper proposes an OFDM based adaptive modulation scheme employing variable coding rate (VCR OFDM AMS), which selects optimum modulation and coding scheme (MCS) realized by combination of several modulation schemes and coding rates. The OFDM AMS with multilevel transmit power control (OFDM AMS/MTPC) can realize high data rate transmission in the dynamic parameter controlled-orthogonal frequ...

This paper studies the transmission control protocol (TCP) performance over a discrete multi-tone (DMT) based asymmetric digital subscriber loop (ADSL) network. The impact of DMT subchannel bit loading on the TCP throughput performance is studied. The simulation results show that there is a threshold for the signal-to-noise ratio (SNR) gap or bit error rate (BER) above which TCP throughput drop...

Abstract— In this paper, a packet combining method known as symbol mapping diversity (SMD) is investigated. In an SMD scheme, the bit-to-symbol mapping in -ary modulation is varied among multiple transmissions of the same packet (e.g., ARQ). It has been shown that multiple transmissions of the same packet using SMD provide better bit error performance than a scheme where the same bit-to-symbol ...

This paper presents a dynamic discrete bit-loading algorithm for multicarrier pDSL communication links that utilize the indoor power line network. In order to confront the timevarying behavior of power line transmission media, the proposed algorithm provides fast adaptive bit and power loading with reduced complexity using channel state information and a subchannel link-allocation profile. Nume...

Abstract— The demand for high speed data services have been increasing day by day, a very promising approach is to use Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM). In this paper adaptive bit loading is applied to MIMO-OFDM, to obtain a bit and power allocation for each subcarrier assuming instantaneous channel knowledge. Relying on the available partial...

Adaptive bit-loading algorithms can improve the performance of OFDM systems significantly. The tradeoff between the performance of the algorithm and its computational complexity is essential for the implementation of loading algorithms. In this paper, we present a low complexity non-iterative discrete bit-loading algorithm to maximize the data rate subject to specified target BER and uniform po...

W-band wireless transmission has attracted a lot of interest due to its wider available bandwidth (i.e. 75-110 GHz). In this article, we propose a direct-detection orthogonal frequency division multiplexing radio over fiber (OFDM-RoF) system via two cascaded single-drive MZMs at center frequency of 103 GHz. We discuss maximum bandwidth of different modulation formats under forward error correct...

This paper explores an optimal bit loading algorithms for a multicarrier system. Specifically, we study the trade-offs between the aggregate bit error rate (BER) of an orthogonal frequency division multiplexing (OFDM) system and the buffering delay of the packets in a transmission buffer. The bit loading framework is formulated as a Markov decision process (MDP) and an optimal loading policy wh...