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—This paper compares the mean acquisition time (MAT) performance of two serial search acquisition schemes over frequency-selective multipath Rayleigh fading channels. Both the conventional cell-by-cell detection and the novel joint two-cell detection are characterized. In contrast to the majority of published results considering only one correct timing(More)
– Luby Transform codes (LT) were originally designed for the Binary Erasure Channel (BEC) encountered owing to randomly dropped packets in the statistical multiplexing aided classic wireline-based Internet, where transmitted packets are not affected by the fading or noise of the propagation environment of the wireless Internet. For the sake of transmitting(More)
—Ultra-wideband (UWB) systems having a bandwidth on the order of gigahertz have recently received wide attention both in the U.S. and in Europe. The family of UWB systems may communicate either by generating ultra-wideband signals or with the aid of innovatively combining conventional narrowband, wideband, or broadband signals. At the time of writing, UWB(More)
—We propose a generic algorithm for the construction of efficient reversible variable-length codes (RVLCs) and variable-length error-correcting (VLEC) codes, which optimizes the code-word length distribution. The algorithm may be applied to any existing codeword selection mechanism, and it is capable of generating codes of higher efficiency in comparison to(More)
— A novel sequential estimation method is proposed for the initial synchronization of pseudonoise (PN) signals derived from m-sequences. This sequential estimation method is designed based on the principle of iterative soft-in-soft-out (SISO) decoding , and hence we refer to it as the Recursive Soft Sequential Estimation (RSSE) acquisition scheme. The RSSE(More)
—In this letter, we extend our investigation of generalized multicarrier direct-sequence code-division multiple access by considering two additional types of chip waveforms, namely, the time-domain half-sine and raised-cosine chip waveforms, in addition to the rectangular chip waveform. A range of closed-form equations are provided for quantifying the(More)
—In this contribution, adaptive rate transmissions are investigated in the context of direct-sequence code-division multiple access (DS-CDMA) systems using variable spreading factors (VSFs). In the context of the recently established family of adap-tive rate-transmission schemes, the transmission rate is typically adapted in response to the channel's(More)
—The concept of multihop diversity is proposed, where all the nodes of a multihop link are assumed to have buffers for temporarily storing their received packets. During each time-slot, the best hop having, for example, the highest signal-to-noise ratio (SNR), is selected from the set of those hops, where the corresponding nodes have packets awaiting(More)