Abstract:
L'invention concerne un dispositif de modulation de données source, délivrant un signal à porteuses multiples. Selon l'invention, un tel dispositif comprend : - un étage de pré-traitement (21), comprenant au moins deux modules de pré- traitement (211, 212, 213) aptes chacun à traiter lesdites données source selon un type de modulation à porteuses multiples distinct; - un étage de transformation mathématique (22) comprenant au moins un module de transformation mathématique (221, 222); - un étage de post-traitement (23), comprenant au moins deux modules de post- traitement (231, 232, 233) aptes chacun à traiter lesdites données transformées selon un type de modulation à porteuses multiples distinct; - des moyens de sélection (113) d'un desdits modules de pré-traitement et d'un desdits modules de post-traitement correspondant, en fonction d'un type de modulation à porteuses multiples à mettre en œuvre.
Abstract:
A wireless communication system comprises a wavelet analyzer and a wavelet signal generator. The wavelet analyzer is operable to analyze wireless signals within a frequency and time map of a communications spectrum, whereby the wavelet analyzer is adapted to determine one or more available cells within the frequency and time map. The wavelet signal generator is operable to generate one or more wavelet signals for transmission within the determined one or more available cells of the frequency and time map based on the analyzed wireless signals within the frequency and time map.
Abstract:
A multicarrier digital transmission signal from digital signal processing unit 1 is converted to an analog signal in analog circuit 2, and is transmitted from transmission lines 61 and 62 via communication transformer 3. Digital signal processing unit 1 includes time carrier detector 12 that detects existence and non-existence of a carrier generated by another apparatus using the transmission line, by using a time waveform of a reception signal and frequency carrier detector 13 that detects existence or non-existence of the carrier by using frequency characteristics of the reception signal. Under the control of the controller 11, carrier detection is performed by switching between activating time carrier detector 12 and frequency carrier detector 13 for operation.
Abstract:
Multiscale communication, wherein time-frequency conditioning off the transmitted signal is used, is examined with respect to typical wireless communications systems, in which the modulating wavelet is matched to a specific channel condition. Compactly supported wavelet bases are employed, and based on their parameterization a wavelet is selected that best characterizes the wireless channel conditions.
Abstract:
The invention disclosed in this application discloses a method for modulating and demodulating compressed binary information that was derived from a binary information stream composed of a binary data sequence of first and second binary states that was modulated onto a carrier which has a waveform with a continuous sequence of wavelets with similar amplitudes defined by a 360-degree cycle (fig. 4) between crossover positions representing a substantially zero energy level in which the carrier has been modulated in accordance with said binary data sequence by grouping said wavelets into wavelet groups containing two or more wavelets (cycles 1-16 in fig. 4), receiving said information stream as a binary data sequence of first and second binary states.
Abstract:
A communication apparatus has an A/D converter which converts an analog signal which was received, into a digital signal, a converter which converts a reception signal so as to enable handling of phase information, a carrier detector which detects presence or absence of the reception signal, a synchronous circuit which extract synchronization timing from the reception signal, an equalizer which corrects the reception signal so as to cancel influence of a transmission path, a transmission path estimator which estimates a state of a power line transmission path and determines a multi-value level of a primary modulation which is used by each sub-carrier of a symbol mapper in a transmitting device, and a judging unit which judges the reception signal, which was amended by the equalizer, by use of a threshold value.
Abstract:
Methods and apparatus for processing data for transmission that reduces discrete power spectral density (PSD) components of a transmitted multi-band wideband signal including the processed data are disclosed. Each band of the multi band wideband signal includes waveforms corresponding to a different band of frequencies. Data is processed for transmission by selectively inverting the data, defining a sequence for modulating the bands of the multi-band wideband signal with the data, and modulating the data onto the waveforms within the bands of the multiband wideband signal in accordance with the defined sequence.
Abstract:
A method is provided for generating a multiple band ultrawide bandwidth signal. In this method, an ultrawide bandwidth devices provides a first reference signal having a first reference frequency, and a second reference signal having a second reference frequency that is different from the first reference frequency. The device generates a first ultrawide bandwidth signal based on the first reference signal, and a second ultrawide bandwidth signal based on the second reference signal, creating two separate frequency bands. These two signals can be generated form the same base clock signal, allowing for significantly simpler implementation and modification.