Journal ArticleDOI
OFDM code-division multiplexing in fading channels
TLDR
It can be shown that OFDM-CDM outperforms conventional OFDM with respect to bit error rate (BER) performance and bandwidth efficiency.Abstract:
In this paper, orthogonal frequency-division multiplexing-code-division multiplexing (OFDM-CDM) is presented and investigated as alternative to conventional OFDM for high rate data transmission. An additional multipath diversity gain can be obtained with OFDM-CDM by spreading each data symbol in frequency and time. The optimum reliability information for the Viterbi (1979) decoder is derived for OFDM-CDM systems, and the tradeoff between spreading and channel coding in OFDM systems is presented. By using efficient interference cancellation or joint detection techniques, it can be shown that OFDM-CDM outperforms conventional OFDM with respect to bit error rate (BER) performance and bandwidth efficiency.read more
Citations
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Multi-Carrier and Spread Spectrum Systems
Khaled Fazel,Stefan Kaiser +1 more
TL;DR: In this paper, the authors provide an in-depth insight into hybrid multiple access techniques based on multi-carrier (MC) transmission, and present numerous hybrid access and air interface architectures including OFDM/CDMA, MC-CDMA and MT-CDMAC over new techniques such as space-time coding and software radio.
Proceedings ArticleDOI
Iterative multiuser receiver in sparse code multiple access systems
Yiqun Wu,Shunqing Zhang,Yan Chen +2 more
TL;DR: This paper considers an uplink SCMA system employing channel coding, and develops an iterative multiuser receiver which fully utilizes the diversity gain and coding gain in the system.
Journal ArticleDOI
A time-frequency domain approach to synchronization, channel estimation, and detection for DS-CDMA impulse-radio systems
TL;DR: This paper deals with synchronization, channel estimation, and detection in ultrawideband (UWB) biphase impulse-modulated systems and shows that the proposed approach exhibits fast convergence, and high performance with and without synchronous/asynchronous MAI.
Journal ArticleDOI
Adaptive spread-spectrum multicarrier multiple-access over wirelines
TL;DR: A new loading algorithm that dynamically handles the system configuration in order to maximize the data throughput is derived and it is shown that SS-MC-MA combined with the proposed loading algorithm achieves higher throughput than DMT in a multiuser PLC context.
Journal ArticleDOI
A new ICI matrices estimation scheme using Hadamard sequence for OFDM systems
Hsiao-Chun Wu,Yiyan Wu +1 more
TL;DR: A lower bound for the mean-square estimation error among the least-square ICI matrix estimators is derived using different training sequences and it is proved that the minimum mean- square error (MMSE) optimality is attained when the training sequences in different OFDM blocks are orthogonal to each other, regardless of the sequence length.
References
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Probability, random variables and stochastic processes
TL;DR: This chapter discusses the concept of a Random Variable, the meaning of Probability, and the axioms of probability in terms of Markov Chains and Queueing Theory.
Digital communications
TL;DR: This month's guest columnist, Steve Bible, N7HPR, is completing a master’s degree in computer science at the Naval Postgraduate School in Monterey, California, and his research area closely follows his interest in amateur radio.
Book
Random variables and stochastic processes
TL;DR: An electromagnetic pulse counter having successively operable, contact-operating armatures that are movable to a rest position, an intermediate position and an active position between the main pole and the secondary pole of a magnetic circuit.