摘要:
A controller in a transceiver for radio communications in which the same frequency is shared between multiple communications systems is disclosed that includes: a cyclic autocorrelation value calculation part configured to calculate the cyclic autocorrelation value of a first one of the communications systems from a received signal; and a data transmission authorization part configured to determine whether to authorize data transmission in a second one of the communications systems based on the calculated cyclic autocorrelation value of the first one of the communications systems.
摘要:
A frequency band allocation device is disclosed. The frequency band allocation device comprises an RF database (112) for storing frequency category information indicating a dedicated frequency band, a registered frequency band or unlicensed frequency band; a user information database (113) for storing user information; a frequency band selecting unit (1161, 1162) for selecting usable frequency bands based on the frequency category information and the user information; and a frequency band allocation unit (1163) for allocating a frequency band satisfying user required QoS out of the selected usable frequency bands.
摘要:
An asynchronous transfer mode (“ATM”) cell transfer system in a wireless communication system provides quality classes that correspond to the amount of cell transfer delay allowed. Cells are classified according to a quality class and stored in buffers. The cells are read starting from the buffer for the quality class with the highest priority, and successively from buffers for quality classes of lower priority. Alternatively, if there is room in the output interval of cells of a higher priority quality class, cells of a lower quality class are inserted among these cells.
摘要:
A digital transmission apparatus is provided, by which the amount of transmission delay and circuit miniaturization can be realized in the case of using an FEC method together with a differential coding method. In the digital transmission apparatus, a digital signal to be transmitted is serial-to-parallel-converted into parallel n-channel signals; each signal is FEC-encoded and encoded signals are then differentially encoded; and a carrier is modulated by the parallel n-channel differentially-encoded signals to be transmitted as a 2.sup.n multi-level modulated signal. The signal is detected at the receiving side and parallel n-channel demodulated and decoded signals are output; FEC decoding is performed; and the parallel n-channel digital signals after FEC decoding is parallel-to-serial-converted. When block coding is used as an FEC method, parallel n-channel digital signals to be transmitted are respectively processed by block-encoding of the same logic; the parallel n-channel signals after encoding are differentially encoded; and a carrier is modulated by the parallel n-channel differentially-encoded signals to be transmitted as a 2.sup.n multi-level modulated signal. At the receiving side, parallel n-channel signals after detection are stored; syndrome data for detecting an error bit position for each signal is calculated; and based on the syndrome data, time-series detection of each error bit position is performed so as to correct the errors included in the stored signals.