Abstract:
In an automobile on-board and/or portable telephone system capable of increasing the capacity of subscribers easily on the basis of changing of the information transmission bit rate, spread codes obtained by multiplying orthogonal spread codes (m in number) by a pseudo-random noise series are assigned to individual channels in the same cell in such a manner that the orthogonal spread codes are multiplied by some types of pseudo-random noise series having different phases, thereby making it possible to maintain the number of channels in the same cell at a value which is a multiple of the number of the orthogonal spread codes. Through this, in the case where the transmission bit rate is halved as compared to the presently existing rate in the future, assignment of spread codes which are increased in number to as large a value as necessary can be achieved and the subscriber's capacity can be increased within a range in which the necessary quality can be maintained even when link paths for m or more channels are set up in one cell from the viewpoint of Signal to Interference Ratio.
Abstract:
In an automobile on-board and/or portable telephone system capable of increasing the capacity of subscribers easily on the basis of changing of the information transmission bit rate, spread codes obtained by multiplying orthogonal spread codes (m in number) by a pseudo-random noise series are assigned to individual channels in the same cell in such a manner that the orthogonal spread codes are multiplied by some types of pseudo-random noise series having different phases, thereby making it possible to maintain the number of channels in the same cell at a value which is a multiple of the number of the orthogonal spread codes. Through this, in the case where the transmission bit rate is halved as compared to the presently existing rate in the future, assignment of spread codes which are increased in number to as large a value as necessary can be achieved and the subscriber's capacity can be increased within a range in which the necessary quality can be maintained even when link paths for m or more channels are set up in one cell from the viewpoint of Signal to Interference Ratio.
Abstract:
A code reader reads code specification information stored in a code list. An interference level measurer measures the interference level of a received signal despread with the code specification information read by the code reader. A threshold selector selects a code specification information corresponding to an interference level smaller than a preset threshold and stores the selected code specification information in a code candidate list. A code determiner determines the code specification information of a base station from the selected code specification information. When a new base station is added, a base station code may be automatically determined without needing a theoretical design for assigning codes to all base stations.
Abstract:
In a PN code generating apparatus, a code of the predetermined number of stages is generated using primitive polynomial G(x), then the code content of each stage is shifted to the next stage. And a state setting section obtains a code state of the PN code generating section after shifted the specific times from a code state of the PN code generating apparatus at a certain time, based on ximodG(x) as the number of shift times is i.
Abstract:
A mobile radio system includes a base station and a plurality of mobile radio apparatuses, with each mobile radio apparatus including a control CPU for controlling the mobile radio apparatus and monitoring the state of the hardware of the mobile radio apparatus, a transmitter unit for transmitting data in the form of radio waves, and a CPU monitor unit. The control CPU regularly monitors and checks for any abnormalities in the hardware of the mobile radio apparatus, and the CPU monitor unit regularly monitors and checks for any abnormalities in the control CPU. If there is an abnormality, a disabled transmission out put acceptance signal is supplied to the transmitter unit to inhibit or suppress the output of radio waves thereby avoiding interference to the system caused by unnecessary radio wave transmission from an abnormal mobile radio apparatus.
Abstract:
A CDMA system in which carriers are segregated according to the self-sacrifice of a mobile station resulting in no communication quality deterioration due to shadowing The mobile station detects a base station which causes a sudden increase in the reception power of the mobile station, and generates self-sacrifice information and transmits the information to the base station communicating with the mobile station. The informed base station detects the self-sacrifice information transmitted from the mobile station and informs mobile communication control equipment. The mobile communication control equipment designates a carrier which is prohibited from future use and the concerned base station. The concerned base station discontinues use of the designated carrier.
Abstract:
In variable bit rate communications in which the information rate changes at B/2.sup.n (where n is 0 or a positive integer) in each frame when the maximum information rate is B, at the transmitter side, information data is convolution coded in order to carry out an error correction of the information data, and when n.gtoreq.1, coded data is repeatedly transmitted by (2.sup.n -1) times. At the receiver side, the information rate is detected from the transmission data that has been received, and when carrying out Viterbi decoding, an information rate is estimated by utilizing the repetition characteristics of the data, so that the coded data is Viterbi decoded for only the estimated bit rate, to thereby restrict an increase in the power consumption of mobile terminal units that are driven by batteries.
Abstract:
A demodulator for a cellular communications receiver system is disclosed which preferentially selects for concurrent demodulation the transmissions which originate from different base stations. The cellular receiver system selects a group of transmissions having the highest reception energies at each reception timing and preferentially assigns those transmissions to be demodulated. The receiver is also equipped to select a second group of transmissions having reception energies other than the highest at each reception timing. The receiver is provided with a priority one table and a priority two table for storing records of the reception energy and reception timing for each respective group of transmissions.
Abstract:
A mobile radio system includes a base station and a plurality of mobile radio apparatuses, with each mobile radio apparatus including a control CPU for controlling the mobile radio apparatus and monitoring the state of the hardware of the mobile radio apparatus, a transmitter unit for transmitting data in the form of radio waves, and a CPU monitor unit. The control CPU regularly monitors and checks for any abnormalities in the hardware of the mobile radio apparatus, the CPU monitor unit regularly monitors and checks for any abnormalities in the control CPU. If there is an abnormality, a disabled transmission output acceptance signal is supplied to the transmitter unit to inhibit or suppress the output of radio waves, thereby avoiding interference to the system caused by unnecessary radio wave transmission from an abnormal mobile radio apparatus.
Abstract:
In an automobile on-board and/or portable telephone system capable of increasing the capacity of subscribers easily on the basis of changing of information transmission bit rate, spread codes obtained by multiplying orthogonal spread codes (m in number) by a pseudo-random noise series are assigned to individual channels in the same cell in such a manner that the orthogonal spread codes are multiplied by some types of pseudo-random noise series having different phases, thereby making it possible to maintain the number of channels in the same cell at a value which is a multiple of the number of the orthogonal spread codes. Through this, in the case where the transmission bit rate is halved as compared to the presently existing rate in the future, assignment of spread codes which are increased in number to as large a value as necessary can be achieved and the subscriber's capacity can be increased within a range in which the necessary quality can be maintained even when link paths for m or more channels are set up in one cell from the viewpoint of Signal to Interference Ratio.