摘要:
An up-link channel assignment scheme for cellular mobile communications systems employing multibeam antennas with beam selection, in which a channel that is selected from among all variable channels in the same frequency band may be assigned to each of the antenna beams in a base station for communications. Channel selection for a base station takes place independently of that for other cells, such that the process is autonomous. Channel selection is based upon an estimate of the signal-to-interference power ration ("SIR") in which a channel having the smallest SIR estimate that is larger than or equal to a given threshold value is chosen. Alternatively, a channel having the largest SIR estimate is selected.
摘要:
A switching center 30 comprises a memory part M2, a memory part M3, and a memory part M4. The memory part M2 stores a terminating terminal number corresponding to and registered by each subscriber. The memory part M3 stores idle/busy information corresponding to each terminal. The memory part M4 stores idle/busy information corresponding to each subscriber. When a subscriber 11.sub.1 makes a call at a terminal 12.sub.2, the switching center 30 determines whether the idle/busy information for the subscriber 11.sub.1 stored in the memory part M4 is idle or busy. When the idle/memory information represents idle, the switching center 30 refers to the idle/busy information for the terminal 12.sub.2 stored in the memory part M3. When this idle/busy information represents idle, the switching center 30 reads out the terminal number of a terminating terminal of a terminating subscriber stored in the terminating terminal memory part M2 and performs an outgoing call connection process. At this point, the switching center 30 also sets the idle/busy information for the subscriber 11.sub.1 and the terminal 12.sub.2 to busy state. When the subscriber 11.sub.1 makes a call, while the terminating terminal 12.sub.1 is performing an incoming call connection process for the subscriber 11.sub.1, since the idle/busy information for the subscriber 11.sub.1 has been set to the busy state, even if the terminal 12.sub.2 is idle, the switching center 30 does not perform an outgoing call connection process for the subscriber 11.sub.1 at the terminal 12.sub.2.
摘要:
A base station of a CDMA communication system includes a transmission de-correlator for eliminating interferences between communication channels of a downlink. The transmission de-correlator has a memory storing a set of data representative of the products of transmission information bits for the respective channels, and the sums of the products of the spread code data sequences for the respective channels, and the elements of an inverse matrix with respect to a predetermined matrix of a cross-correlation between the spread code data sequences for the respective channels. The sums correspond to additions of the products along a direction of columns or to additions of the products along a direction of rows of the inverse matrix. A counting device is operative for causing the memory to sequentially output the data therefrom. An adder serves to calculate a sum of the data outputted from the memory.
摘要:
Radio zones 2a through 2d are each assigned radio frequency channels of the number corresponding to the zone traffic, one frequency f1 of the radio frequency channel is assigned in common to all radio zones, and radio channels of the same frequency are assigned spectrum spreading codes different for each zone. A mobile station is provided with two correlators 14 and 15. If the received signal level lowers when the mobile station stays in the radio zone 2a and is in conversation over the channel of a frequency f2, the mobile station once switches the communication to a channel of the common frequency f1 and continues the communication using one of the correlators, while at the same time the mobile station scans spectrum spreading codes for control channels of the respective radio zones by the other correlator for measuring the received signal levels of the control channels and determines a destination radio zone which provides the maximum received signal level.
摘要:
A device for testing an amplifier. A plurality of PN modulators are provided corresponding to a plurality of oscillators at stages preceding or following them, or fluctuation is given to division ratios at the oscillators. Since each of n carriers combined by a combiner contains phase fluctuation, the possibility that the peaks will overlap each other or that the carriers having opposite phases will negate each other is very low. The peak power in signals supplied to the amplifier to be tested is unlikely to vary, enabling accurate evaluation or testing.
摘要:
In a mobile communication system in which the service area is covered with a plurality of location registration areas each having a plurality of cells each relating to a specific base station, each location registration area has a plurality of groups so that the cells belonging to any group overlaps partly with the cells of other groups, but do not completely coincide with cells of other groups, and each mobile station belongs to one of said groups. When a mobile station moves beyond the border of location registration areas, the location updating for the mobile station is carried out at the cell in which the mobile station stays. In that case, as the mobile stations are classified into a plurality of groups, the traffic in each cell for location updating is dispersed to many cells, and the maximum traffic density for location updating per cell is reduced. So, the number of control channels in the system for location updating may be reduced.
摘要:
When a network pages the temporary user mobile identifier of a mobile station, the mobile station sends a response to the network. Next, the network checks the authenticity of the user using a ciphering key, corresponding to the temporary user mobile identifier and a random number. If the temporary user mobile identifier is authenticated, a normal incoming call acceptance procedure is executed. If the mobile station is authenticated although the temporary user mobile identifier is wrong, the network reassigns a new temporary user mobile identifier to the mobile station and stops the current communication. In communication, the network and the mobile station mutually notify encipherment-onset time and negotiate about encipherment manner with each other. In addition, diversity handover is commenced upon a call attempt. Furthermore, if a branch replacement is necessary, the current branch is replaced by new branches capable of executing the diversity handover. Additionally, when a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, the mobile station uses the same branch structure and the same communication frequency band for all of calls. Additionally, when a new call occurs to or from the mobile station capable of treating a plurality of calls simultaneously, a branch structure and a communication frequency band, which can continue all of the calls, are selected and used. Therefore, the mobile communications system is suitable for transmission of various sorts of data in accordance with the development of multimedia.
摘要:
The writing address supply part 210 supplies writing addresses for writing the bits forming bit sequences corresponding to the header H contained in a frame to be transmitted or stored and bit sequences corresponding to the data D, into the operating memory 220. The reading address supply part 230 alternately supplies to the operating memory 220 a plurality of addresses for reading a plurality of continuous bits corresponding to the header H from the operating memory 220, and an address for reading 1 bit corresponding to the data D from the operating memory 220, and reads the bit sequence such that the bits forming the bit sequence corresponding to the header H are scattered and arranged within the bit sequence forming the data D, from the operating memory. In accordance with such an interleaving device, it is possible to individually randomize frames according to their constituent data, and it is possible to transmit the bits that make up such data in a format which is most suited for said data.
摘要:
The writing address supply part 210 supplies writing addresses for writing the bits forming bit sequences corresponding to the header H contained in a frame to be transmitted or stored and bit sequences corresponding to the data D, into the operating memory 220. The reading address supply part 230 alternately supplies to the operating memory 220 a plurality of addresses for reading a plurality of continuous bits corresponding to the header H from the operating memory 220, and an address for reading 1 bit corresponding to the data D from the operating memory 220, and reads the bit sequence such that the bits forming the bit sequence corresponding to the header H are scattered and arranged within the bit sequence forming the data D, from the operating memory. In accordance with such an interleaving device, it is possible to individually randomize frames according to their constituent data, and it is possible to transmit the bits that make up such data in a format which is most suited for said data.
摘要:
A mobile communication system can implement broadcasting control that generates broadcast information autonomously in a distributed manner, thereby obviating the need for an RNC (Radio Network Controller). Each base station has an IP address and a base station multicast address. Each base station sends its own system information to all base stations using the multicast address. Each base station generates its broadcast information from its own system information and the system information received from other base stations. Thus, it can generate the broadcast information autonomously in a distributed manner without using the RNC.