摘要:
A method for adaptation to an echo location in an echo canceller comprising an output port, an input port, an adjustable delay unit (43) compensating for the pure delay component in the echo path between the echo location and the output port of the echo canceller, a digital filter (40) calculating, from a signal outgoing to the echo path, an echo location estimate which is shorter than the maximum allowed duration of the echo path. The echo location is determined by calculating the echo path location at which there is a high correlation between the signal outgoing to the echo path and the returned echo. The correlation is calculated in a sliding window having the length of the digital filter.
摘要:
The invention relates to a radio system where oriented antenna beams are used over a radio connection between a network subsystem and a subscriber terminal with a fixed location. The network subsystem comprises means for storing parameters of a bidirectional radio connection, including e.g. the transmit beam angle, the receive beam angle, the air interface delay profile, the air interface impulse response, the transmit power of the network subsystem, the transmit power of the subscriber terminal, and the number of rake branches. The network subsystem also comprises a common measuring unit that measures parameters of a bidirectional test radio connection of a new user.
摘要:
A transcoder which prevents tandem coding of speech in a mobile-to-mobile call within a mobile communication system uses a speech coding method for reducing transmission rate on the radio path. The transcoder includes a speech coder, which encodes the speech signal into speech parameters for transmission to a mobile station, and decodes the speech parameters received from the mobile station into a speech signal according to the speech coding method, as well as a PCM coder for transmitting an uplink speech signal to and for receiving a downlink speech signal from a PCM interface in the form of PCM speech samples. In addition to the normal operation, the transcoder transmits and receives speech parameters through a PCM interface in a subchannel formed by least significant bits of the PCM speech samples. Thus, it is possible to prevent tandem coding while maintaining the standard PCM interface, and the signaling and services associated thereto.
摘要:
A method for tuning an RF bandpass filter, especially a combiner filter (10.sub.1, 10.sub.2. . . 10.sub.n) belonging to a GSM system, in which an RF signal having a certain nominal carrier frequency (f.sub.c) is inputted into the RF bandpass filter and a medium frequency of a pass band of the RF bandpass filter is tuned depending on an RF power propagating through the bandpass filter or on an RF power reflected from an input of the bandpass filter. For an easier tuning of the filter and for a tuning accuracy better than before, (a) a carrier is modulated by a signal causing a first predetermined offset (+.DELTA.f), of the carrier frequency, (b) a medium frequency, at which the power propagating through the filter is at the maximum or the power reflected from the input of the filter is at the minimum, is searched for for the bandpass filter, (c) the first medium frequency obtained at stage (b) is stored, (d) the carrier is modulated by a signal causing a second predetermined offset (-.DELTA.f) of the carrier frequency, (e) a medium frequency, at which the power propagating through the filter is at the maximum or the power reflected from the input of the filter is at the minimum, is searched for for the bandpass filter, (f) the second medium frequency obtained at stage (e) is stored, and (g) the filter is tuned by tuning its medium frequency to a value determined on the basis of the frequency values obtained at stages (c) and (f).
摘要:
A direct mode repeater for forwarding traffic between mobile stations communicating on a direct mode channel, includes a transceiver unit for forwarding radio messages between mobile stations communicating on a direct mode channel, and a control unit for controlling the operation of the repeater and for directing the transceiver unit to the direct mode channel. In order to prevent simultaneous transmission of several repeaters on the same direct mode channel. The transmission on the direct mode channel of the repeater that forwards radio messages on the direct mode channel contains at desired intervals the identifier of the repeater, the identifier indicating that the repeater forwards traffic on the direct mode channel. The the repeater is arranged to monitor the direct mode channel as the repeater is seeking to switch onto the direct mode channel, and to switch onto the direct mode channel only if no identifier from any other repeater has occurred on the direct mode channel during a predetermined monitoring period.
摘要:
A cellular radio network and a method for increasing traffic carrying capacity in a cellular network in which the operating frequency spectrum of the cellular network has been divided so that typically both regular frequencies and super-reuse frequencies are employed in each cell. The regular frequencies use a conventional frequency reuse pattern to provide seamless overall coverage (overlay). A very tight frequency reuse pattern is used for the super-reuse frequencies to provide additional capacity (underlay). The cellular network controls the division of traffic into regular and super-reuse frequencies by radio resource allocation at the call set-up phase and later on during the call by handover procedure. The cellular network continuously monitors the downlink co-channel interference of each super-reuse frequency in the cell separately for each ongoing call. The call is handed over from a regular frequency to a super-reuse frequency when the co-channel interference level on the super-reuse frequency is sufficiently low. When the co-channel interference level on the super-reuse frequency deteriorates, the call is handed over from the super-reuse frequency back to the regular frequency.
摘要:
A method for selecting a target group for an operation applied to a network element (NE) of a communication network includes (a) receiving from a network management element information on the operation and on the first target group (S), which is a group of object instances contained in the memory of the network element, and as comparison criteria of object instance attributes, the criteria containing the reference values, (b) comparing the attribute values of object instances belonging to the first target group to said reference values, and (c) selecting the final target group from among those object instances in the first target group (S) that have attributes fulfilling the received comparison criteria. To achieve a general-purpose method, a comparison between the attributes of a single object instance is carried out by (i) reading a semantic data which has been prestored in the network element memory, and which is associated with the attribute, (ii) searching the associated attribute value of the object instance from the network element, and (iii) comparing the attribute value to the received reference value by utilizing the semantic data read.
摘要:
A method for allocating radio channels in a quasi-transmission trunked mobile communication system including base stations and a first mobile station communicating with the base stations using radio channels, and at least one other mobile station requiring a radio channel. In the method, a radio channel is kept reserved for such a call in which the first mobile station is participating. This radio channel is allocated for the first mobile station for the duration of its call transaction. The first mobile station terminates and its call transaction, the radio channel is kept reserved for a predetermined time for the call. For accelerating allocation of new call transactions, it is checked whether the radio channel may still be kept reserved for the call. If the radio channel may still be kept reserved for the call, time-out time (T.sub.s) for a call transaction depending on the traffic load of the radio channels is calculated, and the channel is kept reserved for the time corresponding to the calculated time-out time, subsequent to which the radio channel is released. If the radio channel may no longer be kept reserved for the call, the radio channel is released.
摘要:
A dielectric resonator structure includes a resonator made of a dielectric material. The resonator is supported between two support plates and can be displaced at least in one direction between the plates. At least one of the plates is made of a dielectric material so that the amount of the dielectric material of the support plate varies in the direction of displacement of the resonator.
摘要:
A method and system for controlling a statistically multiplexed ATM bus, to the bus being connected a bus controller and interface units for transmission of packets, i.e. cells, over the bus, in which, having detected, for each cell to be transmitted to an ATM bus, the address of the interface unit participating in the transmission, the bus controller sets the address on an address bus of the ATM bus, thereby activating transmission of the cell from the bus controller to the interface unit, or vice versa, over a data bus of the ATM bus. During the transmission of the cell, the bus controller fetches the next interface unit address for transmission of the next cell from or to the interface unit concerned.