Journal ArticleDOI
On digital single-sideband modulators
TLDR
The 12 Weaver modulators can be transformed as a system, to reduce the multiplication rate for the Hartley system by a factor 4, and the cost is an increase in scratch pad storage and a more complex program.Abstract:
This paper concerns digital single-sideband modulators with analog inputs and outputs. A group of 12 modulators is treated as a single system, with analog-to-digital converters at 12 input ports and a digital-to-analog converter at a single output port. Tradeoffs are obtained between computational parameters. Substitution of digital counterparts for the phase shifters and product modulators in 12 analog Hartley modulators gives a simple program. However, operation in real time requires quite a large number of multiplications per second. A similar digitalization of 12 Weaver modulators requires even more multiplications. However, the 12 Weaver modulators can be transformed as a system, to reduce the multiplication rate for the Hartley system by a factor 4 . The cost is an increase in scratch pad storage and a more complex program.read more
Citations
More filters
Journal ArticleDOI
A technique for orthogonal frequency division multiplexing frequency offset correction
TL;DR: It is shown, and confirmed by simulation, that to maintain signal-to-interference ratios of 20 dB or greater for the OFDM carriers, offset is limited to 4% or less of the intercarrier spacing.
Journal ArticleDOI
An Orthogonally Multiplexed QAM System Using the Discrete Fourier Transform
TL;DR: This paper provides a novel digital signal processing method based on an N /2-point DFT processing in the O-QAM system that is more economical than the digitally implemented conventional single-channel data transmission system.
Journal ArticleDOI
Digital filtering by polyphase network:Application to sample-rate alteration and filter banks
TL;DR: A more substantial gain can be obtained in the direct realization of a uniform bank of recursive filters through combination of the polyphase network with a discrete Fourier transform (DFT) computer; savings in hardware result from the low sensitivity of the structure to coefficient word lengths.
Proceedings ArticleDOI
Polyphase quadrature filters--A new subband coding technique
TL;DR: A new method of implementing filter banks for subband coding of speech by combining the quadrature filter characteristic with the polyphase network implementation of filter banks, which requires 35% fewer computations than existing designs.
Broad-band OFDM radio transmission for multimedia applications : Video Transmission for Mobile Multimedia Applications
TL;DR: The objective of this paper is to describe the large potential, the flexibility and adaptivity of the OFDM transmission technique in frequency-selective and time variant radio channels.
References
More filters
Journal ArticleDOI
Synthesis of Reactance 4-Poles Which Produce Prescribed Insertion Loss Characteristics: Including Special Applications To Filter Design
Journal ArticleDOI
A Third Method of Generation and Detection of Single-Sideband Signals
TL;DR: In this article, the authors presented a third method of generation and detection of a single-sideband signal, which is basically different from either the conventional filter or phasing method in that no sharp cutoff filters or wide-band 90° phase-difference networks are needed.
Journal ArticleDOI
Computation Methods for Broad-Band 90° Phase-Difference Networks
W. Albersheim,F. Shirley +1 more
TL;DR: The pole-zero frequencies and phase deviations of four-, six-, and eight-pole broad-band 90° phase-difference networks are derived by algebraic means and the results agree with those obtained by elliptic functions but lead to simpler computer solutions.