摘要:
In an OFDM mobile communications system, an algorithm for forming a preliminary estimate of the channel on pilot subcarriers is carried out. Based on this preliminary estimate, a channel property is estimated. This channel property is then used to decide whether to enter a mobile receiver mode or a stationary receiver mode. For example, in the mobile mode channel estimation is performed using only pilot symbols from the current symbol period, while in the static mode channel estimation is performed using pilot symbols from the current symbol period and pilot symbols from other symbol periods.
摘要:
In a receiver for processing OFDM encoded signals, wherein the OFDM encoded digital signals are transmitted by means of a symbol in each of subcarrier frequency channels, with at least some of said subcarriers containing user data symbols, an initial estimate of a channel frequency response is formed from magnitudes of user data symbols received in those subcarriers. Then, a correlation function of a channel impulse response is estimated by performing an inverse Fourier transform on the initial estimate of the channel frequency response, and the length of the channel impulse response is estimated by examining peaks in the estimated correlation function of the channel impulse response.
摘要:
In time varying OFDM systems, the effect of a non-ideal time synchronization may lead to a poor performance in terms of decoded average bit error rate versus the signal-to-noise ratio. The receiver apparatus (3) of the transmission system (1) estimates a subcarrier-dependent channel frequency response and determines an intercarrier interference spreading on the basis of a cyclic shift in symbols carried by the subcarriers. Therewith, an intercarrier interference included in an OFDM signal can be canceled, even in case of a non-ideal time synchronization.
摘要:
In time varying OFDM systems, the effect of a non-ideal time synchronization may lead to a poor performance in terms of decoded average bit error rate versus the signal-to-noise ratio. The receiver apparatus (3) of the transmission system (1) estimates a subcarrier-dependent channel frequency response and determines an intercarrier interference spreading on the basis of a cyclic shift in symbols carried by the subcarriers. Therewith, an intercarrier interference included in an OFDM signal can be canceled, even in case of a non-ideal time synchronization.
摘要:
In a receiver for processing OFDM encoded signals, wherein the OFDM encoded digital signals are transmitted by means of a symbol in each of subcarrier frequency channels, with at least some of said subcarriers containing user data symbols, an initial estimate of a channel frequency response is formed from magnitudes of user data symbols received in those subcarriers. Then, a correlation function of a channel impulse response is estimated by performing an inverse Fourier transform on the initial estimate of the channel frequency response, and the length of the channel impulse response is estimated by examining peaks in the estimated correlation function of the channel impulse response.
摘要:
The invention relates to a disaggregation apparatus for identifying an appliance in an electrical network (2) comprising multiple appliances (3, 4, 5). A voltage meter (7) measures a first change in a mains voltage (V) delivered to the appliances of the electrical network, while an operational state of an appliance is modified, and a second change in the mains voltage, while a switchable load is switched. An appliance determination unit (9) determines the appliance, of which the operational state has been changed, based on the measured first change in the mains voltage, the measured second change in the mains voltage and the resistance of the switchable load. Thus, an appliance can be determined without detecting switching flickers in very short time durations, i.e. high sampling rates and continuous monitoring are not necessarily required. This reduces the technical efforts of the disaggregation apparatus for performing the disaggregation function.
摘要:
The invention relates to a disaggregation apparatus (1) for identifying an electrical consumer in an electrical network (2). An electrical signature providing unit (7) provides electrical signatures of the electrical consumers (4, 5, 6), and an electrical parameter determining unit (8) determines an overall electrical parameter of the electrical network (2). An identification unit (9) identifies an electrical consumer depending on the determined overall electrical parameter and a correlation of the electrical signatures. Since the identification unit identifies an electrical consumer depending on the determined overall electrical parameter and a correlation of the electrical signatures, the identification of an electrical consumer does not depend on the detection of an event only. This makes the identification more robust, especially less prone to errors caused by missed events, thereby improving the reliability of identifying an electrical consumer in the electrical network.
摘要:
A method of synchronizing multi-carrier systems is provided, wherein the method comprises inserting a predefined frequency domain signal into a signal on a transmitter side of a multi-carrier system and multi-carrier modulating the signal. Furthermore, the method comprises transmitting the multi-carrier modulated signal via a carrier channel to a receiving side of the multi-carrier system, and synchronizing the multi-carrier modulated signal by using the predefined frequency domain signal portion of the multi-carrier modulated signal.
摘要:
The invention relates to a disaggregation apparatus for identifying an appliance in an electrical network (2) comprising multiple appliances (3, 4, 5). A voltage meter (7) measures a first change in a mains voltage (V) delivered to the appliances of the electrical network, while an operational state of an appliance is modified, and a second change in the mains voltage, while a switchable load is switched. An appliance determination unit (9) determines the appliance, of which the operational state has been changed, based on the measured first change in the mains voltage, the measured second change in the mains voltage and the resistance of the switchable load. Thus, an appliance can be determined without detecting switching flickers in very short time durations, i.e. high sampling rates and continuous monitoring are not necessarily required. This reduces the technical efforts of the disaggregation apparatus for performing the disaggregation function.
摘要:
The present invention relates to a method and apparatus for disaggregation of energy consumption in a power distribution system. The basic idea is to look at the overall energy consumption and recognize the contributions of each single electrical device (120), e.g. for the purposes of providing a breakdown of energy consumption to users. Disaggregation is assisted by usage of multi-modal system data coming from various external data sources (106-1 to 106-n), such as building management systems and/or IT infrastructure, to relate activities of people or devices to changes in power consumption.