Abstract:
The present invention relates to a vectoring chip unit in a DSL system connectable to a plurality of DSL ports of a DSL chip comprising means for receiving data from each of the plurality of DSL ports, means for performing pre-coding/ cancellation in order to reduce crosstalk and means for transmitting a result of the precoding/canellation to the respective DSL port. Preferably, a system is provided comprising a plurality of said vectoring chips, whereby each vectoring chip is adapted to handle pre- coding/ cancellation of a predetermined frequency range and the frequency ranges of each vectoring chip are non-overlapping.
Abstract:
Modern multi-carrier techniques using orthogonal carriers with high order QAM constellations for the transmission of a plurality of bits per carrier and symbol, use some method for the determination of an inverse channel model to be used in an equalisation process. In the frequency domain, this is normally based on an estimate of the channel attenuation and phase for each carrier. The present invention provides a simplified method of equalisation that uses data at the symbol detector input and output to adaptively estimate an inverse channel model.
Abstract:
In a two-way multi-carrier transmission system, such as a DMT system, in which there can be dynamic changes in the transmission parameters, some means must be provided for maintaining synchronisation between transmitter and receiver when the transmission parameters change. The first stage of such a process requires that changes of parameter be notified by one transceiver to the other, involved in an active communication process, over a slow transmission channel, the control channel. Subsequently the synchronisation of the transceivers is adjusted simultaneously, i.e. from a predetermined DMT symbol. Such adjustements in time synchronisation must be achieved with a minimum of overhead.
Abstract:
The invention relates to a device (1) at a window (2) that comprises a window pane (4) received in a window casement (3) with the casement (3) and the pane (4) receivable in a window frame (5), turnable 180° or more around a pivot bearing (8) and locked to the frame (5) by means of lock plungers (6, 7), which are receivable in guiding grooves (9, 10) in the casement (5). According to the invention, in each corner (A-D) of said frame (5), a control mechanism (11) is arranged for the regulation of the motion of said lock plungers (6, 7). A control (27) for the actuation of said lock plungers (6, 7) is arranged on the window frame (5) and the control mechanism (11) comprises a cam surface (14) that is co-operatable with a motion transfer part (19) for the lock plungers (6, 7). The window casement (3) is optionally openable at the top or bottom, turnable, angleable into the desired position as well as lockable by the actuation of controls (12 and 13, respectively; 27) therefor.
Abstract:
The invention relates to an arrangement (1) for a window (2) or some other covering element, which exhibits a window casement (4) or other outer casement for a covering element pivotally mounted and capable of being accommodated in a window frame (3) or some other frame. In accordance with the invention, an air admission passage (5) is present along at least one part of the aforementioned frame (3) and the outer casement (4) when the window (2), etc., is retained in the closed position. Arranged on the inside of the aforementioned window (2) is a preferably pivotally mounted covering frame (7) for closing and opening the aforementioned passage (5).
Abstract:
The invention concerns a mechanism (1) for a window (2), which is displaceably guided along grooves (4) and mounted pivotably 180° and 360° around a horizontal bearing spindle (5) and which comprises means (6 and 7, respectively) for the guiding and locking, respectively, of the window (2). According to the invention, a single handle (10) or another lever is situated or coupleable in the frame (8) or casement (9) of the window is connected with said locking means (7) for the window (2) and/or is connectable with said guiding means (6) for the window (2), whereby the locking and guiding, respectively, of the window is arranged to be provided by said single handle (10) or lever.
Abstract:
The invention provides a multi-carrier transmission system, for example, a DMT based VDSL system, using orthogonal carriers with high order QAM constellations for the transmission of multiple bits per carrier and symbol, said system including digital receiver and transmitter units, said receiver unit including a symbol detection unit, characterised in that said system is adapted to determining a parameter for each single carrier, said parameter being indicative of a deviation of a received signal from a corresponding constellation point; comparing the parameter with an upper and lower limit; and, if the parameter is outside said limits, changing the constellation used to modulate the carrier to a neighbouring constellation. The symbol detection unit may be used to determine the parameter which may be a ratio d / sigma , where d is the shortest distance between neighbouring constellations, sigma is a standard deviation, and sigma is the variance of the deviations of the input and output signal values of said symbol detection unit.
Abstract:
The invention provides a multi-carrier transmission system, for example, a DMT system, in which channel information is transmitted between two transceivers using a plurality of sub-carriers, characterised in that each sub-carrier, or symbol, has a parameter associated therewith, and in that said transceivers are adapted to transmit said channel information as a sequence of n groups, in which each of said n groups contains information concerning the number of adjacent sub-carriers which have the same value as said parameter, together with the actual value of the parameter. The parameter which may have a plurality of discrete values, may be a bit-loading value, or a QAM constellation identifier.
Abstract:
In a multi-carrier system, such as a DMT system, a receiver must be able to recover a sampling clock that is very accurately synchronized to a transmitter sampling clock. Typically, synchronization is achieved by using a reserved carrier, the pilot carrier, which is transmitted with a fixed phase. The receiver sampling clock is then phase locked to the pilot carrier. Frame timing can be recovered by using a correlation technique. The present invention provides an improved method of recovering a sample clock and phase locking the sampling clock to a pilot carrier.