Abstract: A wireless transmission system operating in a 60 GHz frequency range comprises fixed hubs (public download server) (2) and mobile terminals (1). The fixed hubs (2) have antennas (4) with a wide angle beam shape. The mobile terminals (1) have antennas (3) with a narrow angle beam shape. The fixed hubs (public download server) (2) are connected by means of a connection line (5) to an information source such as a network backbone or a main server.

Abstract: The universal platform for the SDR of the present invention employs the direct conversion approach with the n-port MMIC followed by reconfigurable reprogrammable devices such as DSP's or FPGA's. The universal platform is based on the linear operation of the devices. Thus, the DC offset problem may be solved. It is also possible to support very wide bandwidths compared with conventional I/Q receivers. Therefore, the present universal platform is suitable for multimode and multiband communications.

Abstract: A three port structure for the down conversion demodulation of a digitally modulated RF signal is proposed, wherein no RF switches are provided. The three port structure (1) has a first input (2) for the RF signal to be down converted and a second input (3) for a RF signal originating from a local oscillator (8). An output (4) of the three port structure (1) is supplied to a power sensor unit (5). The RF signal from the local oscillator (8) is modulated (7) before it is supplied to the three port structure (1).

Abstract: A time slot which is formed by time-division multiplexing is divided into a plurality of blocks in at least a frequency direction, and also within each one of said plurality of blocks a plurality of subcarriers are formed. A predetermined number of plurality of blocks forms one communication channel, whereby a plurality of communications are formed within a time slot. With this, one time slot can be multiplexed by communication of multiple carriers separated in frequency. In this manner, with simple constitution, communication can be performed satisfactorily even in an environment where a multiple path is present.

Abstract: In a data decoding apparatus, the Viterbi algorithm is used in an equalizer so that the difference data between state metrics is used as reliability data with respect to the output data so as to provide the reliability data which can accurately represent the likelihood of the output data, whereby it is ensured that efficient decoding of data may be performed based on the reliability data described above.

Abstract: A radio receiver for a digital cellular system or the like which transmits or receives, for example, voice signals by coding them, and easily and reliably detects a synchronizing signal. A synchronizing signal FCCH is detected by converting a base band converted transmitted signal with an analog-to-digital convertor circuit 17, and then by detecting a correlation value with a predetermined reference signal.

Abstract: In a radio apparatus of such as digital cellular which transmit and receive audio signals upon coded, the frequency error can be detected easily and certainly even in the environment of high noise level. The frequency error .theta..sub.e is detected according to the detection result of the complex correlation value between the synchronizing signal and the standard signal.

Abstract: A radio receiver apparatus and method for decoding a received signal based on a predetermined pattern of synchronization signal which is inserted in a predetermined period comprising demodulating a received signal to a base band signal, decoding the demodulated signal to a data signal, generating a reference signal based on an output of the decoding and detecting a complex correlation value between the data signal and the reference signal wherein the detected synchronizing signal is based on the detected complex correlation value and decoding is based on the detected synchronization signal.

Abstract: A transmission apparatus which can realize high demodulation efficiency even in the case where the channel characteristic is deteriorated. The same pattern data as those of the known pattern data contained in the transmitting data to be transmitted to the channel is generated on the receiving side and the correlation between said pattern data and the receiving data to be received through the channel is obtained. Then, the channel characteristic is successively estimated based on the correlation value and the receiving data will be demodulated depending upon said estimated result. Thus, since the channel characteristic can be estimated based on the receiving data, the data can be demodulated correctly even in the case where the receiving data is distorted due to the characteristic deterioration.

Abstract: A radio receiver for a digital cellular system or the like corrects a doppler frequency shift with a simple arrangement. A phase difference of received data I,Q is corrected by generating an estimated signal EXn through estimation of the received data I,Q corresponding to transmitted data y estimated for the maximum likelihood by a maximum likelihood determination circuit 25, by detecting the branch metric BM, BM+, or BM- in which the estimated data is in phase with the received signal, or in the leading or trailing phase to the received signal, respectively, by detecting the phase difference of the received data I,Q from the estimated signal EXn based on the result of comparison of the branch metrics BM+, BM, and BM-, and by correcting the phase difference based on the result of detection of the phase difference.

Abstract: A receiver system for a mobile telephone system comprises two or more antenna spaced a distance apart from each other greater than the wavelength of incident radiation, and a receiver. Each antenna is coupled to a respective receiver channel of the receiver, each receiver channel comprising an RF means for processing the received signals, and equaliser means for equalising and/or decoding the signals from the RF means. The equaliser means includes metric generating means for generating metric information which provides probability measures for a sequence of time intervals and for a multiplicity of possible states of the receiver within each time interval that the received signal has put the receiver into the respective states, and selector means for comparing the values of corresponding metrics from respective receiver channels for selecting received data from the receiver channel having the higher probability of accuracy.