Abstract: The invention relates to a data transmission method, a transmitter and a receiver in a system which utilizes the CDMA method, in which several users communicate simultaneously on the same frequency band, and in which each user has its own spreading code, and in which the information channel capacity of at least one user differs from the capacity of the other users, the receiver comprising converter means for converting a received transmission into a digital form, and a number of means for synchronizing and for calculating the characteristic required for a decision from the transmission of each received user.

Abstract: The aim of the invention is to restrict the maximum transmitted power used by a mobile communication device. In most countries there are regulations in force which impose certain maximum limits on the power of electromagnetic radiation directed towards humans. These limits vary from country to country and will most probably be tightened in the future. In the system according to the invention, the upper limit of transmitted power is varied according to the mode of usage of the mobile communication device. A mobile communication device according to such a system meets the requirements made on a device operating close to the user's head, but the same mobile communication means may still be used in applications demanding greater transmitted power in a situation where the power limits placed on the radio set are less strict.

Abstract: A base station, subscriber terminal, and data transmission method in a CDMA cellular radio network having in each cell at least one base station which communicates on a specified traffic channel with the terminal equipments (Mobile Station) located within its area, the signal of the users being divided in the method into bursts in the time domain. To achieve high traffic capacity together with high-quality connections, the base station monitors the load state of the traffic channel in the data transmission method of the invention and transmits information about the load state of the traffic channel to the terminal equipments. In the method, the number of the bursts transmitted between the terminal equipments and the base stations per time unit is controlled on the basis of the delay state of the bursts and the load state information computed at the base station.

Abstract: A base station, a subscriber equipment, and a method for synchronizing the subscriber equipment with the transmission of the base station in a digital cellular radio network utilizing the CDMA multiple access method. In each cell of the network, at least one base station communicates with the subscriber equipment within its area, in which network the base station transmits a separate pilot channel provided with a predetermined spreading code. In order to facilitate the synchronization of the subscriber equipment, the base station transmits a data-modulated signal on the pilot channel.

Abstract: A receiver and a method of setting the frequency of the reference signal in the receiver, the receiver comprising a voltage controlled crystal oscillator which provides the reference frequency for a synthesizer. The synthesizer in turn produces the local oscillator frequency signal in the receiver. Temperature fluctuations in the crystal are compensated for by microprocessor control of the oscillator. The reference frequency is accurately set by incrementaly scanning the signal channel until a signal of magnitude greater than a predetermined level is detected, whereupon the receiver locks onto said detected signal and instructs the oscillator to produce a reference frequency signal of a certain frequency according to the frequency of said detected signal.

Abstract: The invention relates to a data transmission method in a CDMA cellular radio system, which comprises in each cell at least one base station (10) communicating with mobile stations (11, 12) within its coverage area and in which system the base station adjusts the transmitting power of the mobile stations within its area by means of power control massages. To enable coherent detection at the base station, according to the method the transmission on the traffic channel is performed both in the transmission direction from the mobile station to the base station and from the base station to the mobile station by using a similar frame structure. When the base station transmits a power control message to the mobile station by using bits of the frame structure of the traffic channel, the mobile station transmits a predetermined bit pattern to the base station in the corresponding bits of the other transmission direction of the traffic channel.