摘要:
A data transmission method in a system employing information channels having at least two different capacities, on which channels speech is transmitted by at least two different coding techniques in such a manner that on a channel having a higher capacity, fewer symbols to be transmitted are coded from the same speech signal block than on a channel having a lower capacity, includes speech coding, channel coding, dividing the speech signal block, combining parts, adding error correction symbols, adding rail symbols, and convolution coding. It is also possible that the convolution-coded symbols are transmitted as interleaved or that the channel-coded signal is transmitted over the full rate channel. As a result of this method, the cell size of a radio telephone system and thus, the coverage area of the system, is extended without large changes in equipment or without an increase in transmission power.
摘要:
For accomplishing an interference-free handover in a cellular communication system which has at least one base station per cell, which base station is controlled by a base station controller which controls one or more base stations, and which base station controller, with the base station or stations under its control, forms a base station system, the respective service areas of respective base stations under different base station controllers at the border or borders of two or more base station systems are caused to at least partly overlap. As a terminal equipment moves from one base station system to another, handover of the terminal equipment from one base station to another is carried out so that as the terminal equipment moves into a cell served by all of two or more base stations which belong to areas of different base station controllers, the terminal equipment carries out a soft handover from an existing base station to a new base station, and, as it further moves towards a respective cell border, it carries out a hard handover from the previously serving base station the previously serving base station system to a respective base station of the newly serving base station system, the service area of which at least partly overlaps with that of the previously serving base station.
摘要:
The present invention provides a method and respective entities for avoiding handovers in a ping-pong manner in a communication network. The method comprises comparing, when a handover of a mobile station to a base station is intended, decision criteria of the intended handover with decision criteria of previous handovers of the mobile station to that base station, and deciding on allowing or preventing the intended handover based on the result of the comparison.
摘要:
A method includes communicating a number of first frames using a first communication scheme. Each of the first frames has one or more first active time periods. Communication of the first frames uses a first frequency band. The method includes communicating a number of second frames using a second communication scheme. Each of the second frames has one or more second active time periods. Communication of the second frames uses a second frequency band that at least partially overlaps the first frequency band. The communication of the first frames and communication of the second frames operate so that at least a portion of the first and second frames overlap in time but the first and second active time periods do not overlap in time. Apparatus and computer program products are also disclosed. An additional method is disclosed for providing coexistence of two time-division systems.
摘要:
A TDMA cellular radio system and a method of allocating available frequency bands to different cells in a TDMA cellular radio system wherein at least some of the receivers within the system use interference cancellation methods which cancel the effects of co-channel interference in a desired signal. To enable efficient use of interference cancellation and the resulting capacity increase in the system, the frequency bands available for the cellular radio system are allocated to different cells so that groups of adjacent service areas are formed in the system. Each group uses the same frequency band within the service areas, whereby at least one co-channel signal interfering with the desired signal is significantly stronger than other co-channel interfering signals.
摘要:
The invention relates to a method for transmitting calls of different priorities in a cellular network which comprises in each cell at least one base station (10) communicating with subscriber terminals (11a-11d, 13) within its area, and in which network the base station transmits power control information to the terminal equipments, which may adjust their transmit power on the basis of the power control messages from the base station, the calls of the network having different levels of priority. In order to ensure the call establishment and the quality of calls with a high priority, the calls with a high priority use a higher transmit power than what is allowed for calls with a lower priority.
摘要:
The base stations of a cellular radio system direct their respective antennas effectively towards the terminal equipment with which they are respectively communicating. Each terminal equipment maintains and updates a list of base stations serving and potentially available to serve the respective terminal equipment. Updating is based on measuring signal strengths and directions, as well as directions of motion of the respective terminal equipment, so that each list, as updated includes only those base stations serving, and on the basis of forecast direction of movement of the terminal equipment, likely to be able to serve the respective terminal equipment. The terminal equipment measure signal strengths for the listed base stations, to determine the need for a handover.
摘要:
Interference in a cellular CDMA network due to mobile stations causing multiple use of one carrier frequency in neighboring cells is cancelled. A hard handover is implemented by defining the phase of a spread spectrum code in a signal transmitted from a base station to a mobile followed by measurement of signal strength in the mobile. Thereafter, the result is reported to the CDMA network, inferring whether the mobile interferes with the base station of the neighboring cells. If interference is present, the surrounding base stations are informed about the mobile station channel used, and this information is taken into account in the receivers of signals transmitted by other mobiles within the cell. The measurement results of the mobile are provided as initial values to the parameters required by the initialization of the interference cancellation routines performed in a neighboring base station. In another embodiment, it is decided whether the mobile station has to be monitored at the neighboring base stations by comparing the measurement results with a predetermined threshold value.
摘要:
A receiver, and a method for estimating received power in a cellular radio system having in each cell at least one base station communicating with mobile stations within its coverage area. The mobile stations measure strength of the signal received from a base station, and report the measurement results to that base station. To improve power adjustment, a model describing the dynamic behavior of the signal is created for the received power on each connection. The model is utilized for power adjustment, as well as for making handover decisions.
摘要:
A mobile station, and a method for eliminating multiple-access interference in a CDMA cellular radio system having a plurality of cells each having at least one base station communicating with mobile stations residing in the respective cell and informing the respective mobile stations of at least one spreading code used in a neighboring cell, the mobile stations measuring the code phase and power level of a channel of the neighboring cell using the known spreading code. To reduce the effect of multiple-access interference, the signal received at the mobile station is utilized in the detection of the desired signal by using the code phase and power level of the measured channel using the known spreading code of the neighboring cell.