Abstract: Terminal devices F and G store statistical information related to interference from an external communication system, and notify the stored statistical information to a master station E. The master station E determines the terminal device G as a candidate station for a master station capability handover destination based on collected statistical information. The master station E requests to hand over a master station capability to the terminal device G. If it is determined that the terminal device G accepts handover of the master station capability, the terminal device G starts to act as the master station.

Abstract: A spreading code generating apparatus (10) carries out M-sequence multiplication and zero value addition of generated orthogonal codes to obtain channel identification codes, and then carries out inverse Fourier transform of the channel identification codes to generate spreading codes (121) and inverse spreading codes (131). A transmitting apparatus (20) and a receiving apparatus (30) store the spreading codes (121) and the inverse spreading codes (131) generated by the spreading code generating apparatus (10), respectively, and use a single code respectively selected from the stored codes to carry out spread spectrum communication. With the use of the spreading codes for spreading, the input signal is spread over a wide frequency band with uniform power on the frequency axis. Thus, transmission characteristics are improved, and multiplexing capacity is increased.

Abstract: An access control method applicable to a network including a plurality of communication terminals for achieving simplification in processing, improvement in response, and efficient use of bands is provided. In a terminal station 21, a transmission information generating section 213 generates predetermined transmission information based on the amount of data stored in a buffer section 212. A packet transmitting section 214 generates a packet including data and the transmission information for transmission to another terminal station 22. In a control station 11, a packet receiving section 111 receives the packet transmitted by the terminal station 21. A transmission information obtaining section 112 analyzes the received packet to obtain the transmission information and, based on the transmission information, determines whether the band currently allocated is to be changed.

Abstract: An efficient medium dedication schedule is generated. The schedule gives wireless medium an ability to concurrently serve real-time and non real-time application and still be able to maintain the Quality of Service as requested by the real-time application. Furthermore, QoS registration request is delivered in a time bound manner and a time slot is chosen for transmission during controlled contention phase that give lesser collision and higher throughput.

Abstract: A diversity apparatus includes antennas 1a, 2a, demodulators 2a, 2b, and a Viterbi decoder 3 that has four ACS sections 41-44, and a path memory 5. Signals convolutionally encoded with a constraint length of 3 are received by two antennas 1a, 1b, are demodulated by the demodulating sections 2a, 2b, respectively, and are then outputted to all of the ACS sections 41-44. Such information coming from different routes are subjected to route selection and ACS processing simultaneously, thereby finding a code sequence (expected values) closest to received data sequences (the plurality of received signals). Then, the single path memory 5 is used to store and/or update the paths for error correction, and then corrected data Dout is outputted.

Abstract: A communications method achieving high transmission efficiency is provided. Provided with permission for communications in a specified time period P1, a wireless station 2 calculates the number of packets transmittable in the time period P1, and successively sends a series of data packets 109 through 112. A wireless station 3 receives the series of data packets, and then sends a response packet 113. When the wireless stations 2 and 3 completes communications before the time period P1 passes, a control station 1 forcefully terminates the permission for the communications.

Abstract: In serial transmission of a mixture of isochronous data and anisochronous data, communications thorough a transmission path with a high ratio of occurrence of transmission errors may disturb images during streaming reproduction and produce noise in sound. To solve this problem, the isochronous data that has not been successfully received is retransmitted using an anisochronous region. Thus, transmission error of the isochronous data can be reduced without impairment of isochronous characteristics of the data.

Abstract: A master station performing continuous operations is communicatively coupled with a plurality of remote stations performing intermittent transmission/receiving operations in constant cycles. Control units of the remote stations control radio communication devices to transmit synchronizing signals to the master station in constant cycles respectively. When the synchronizing signals are received from the remote stations, a control unit of the master station acquires information of corresponding intermittent receiving timing from a memory device, and controls a radio communication device to perform transmitting operations to the remote stations in coincidence with the intermittent receiving timing. Further, the control unit of the master station reads random number values from a random number generator in re-transmission of data, and shifts data transmission timing from original timing by time corresponding to the random number values.

Abstract: An adaptive antenna includes a buffer for storing sample data obtained by sampling a receive signal, an information storage part for storing a plurality of sets of coefficients, an evaluation part for calculating an evaluation value of the result obtained by the coefficient and the sample data, a selection part for selecting two or more sets of coefficients in order of decreasing evaluation, an exchanging part for exchanging a part of coefficients between the selected sets of coefficients to generate a new set of coefficients, a changing part for changing a part of coefficients of the selected sets with random numbers to generate a new sets of coefficients, a reproduction part for reproducing the selected sets of coefficients as they are, and a determination part for outputting the result obtained by the set of coefficients with the highest evaluation value after the information storage part, the evaluation part, the selection part, the exchanging part, the changing part, and the reproduction part repeats res

Abstract: A down-link frame generating/transferring portion 12 detects a free channel from among a plurality of previously assigned up-link channels. The down-link frame generating/transferring portion 12 selects a secondary station 2 to which the free channel is to be assigned by referring to an address table 11 every time it detects a free channel. Then the down-link frame generating/transferring portion 12 sends out onto a down-link channel a down-link frame in which the secondary station address of the selected secondary station is set in an address slot corresponding to the free channel.

Abstract: A complex multiplier 5 complex-multiplies base band signals x and y obtained from a receive signal by local oscillation signals c and s, to output complex detection signals p and q. A phase difference detecting portion 7 outputs the amount of the detected phase difference corresponding to the phase difference between the phase of the receive signal and the phase of the local oscillation signals. A loop filter 8 emphasizes its DC component. A local oscillation portion 6 outputs local oscillation signals having a frequency corresponding to the amount of the detected phase difference. A region judging portion 9 judges which of regions on a complex plane is one to which the base band signals belong, and outputs a region signal. A most frequent region judging portion 10 judges which of the regions is one in which the base band signals are concentrated most frequently upon input of the region signal a predetermined number of times.

Abstract: A device consists of: a first unit which divides voice and image data into blocks each consisting of a predetermined number of data, and executes a method of selecting one of plural error correction encoding systems and conducting encoding on an arbitrary number of data in one block; a second unit which executes a method of measuring an error state of a communication channel; and a third unit which executes a method of determining data which are to be subjected to encoding conducted in the first unit, and an error correction encoding system. When the state of the communication channel is inferior, only data of high importance can be protected. When the state is superior, a wide range of data including those of low importance can be protected.

Abstract: A time window detection portion 3a outputs a time window detection pulse from a time window signal generated in a time window generating portion 2a and a zero-cross detection pulse detected in a zero-cross detection portion 1a. First and second phase storage portions 4a and 5a store output phase values of a phase counter 22 for different times as first and second phase values, respectively. A center phase computing portion 6a computes a first center phase value from the first and second phase values and a center phase storage portion 7a stores the first center phase value of the last time as a second center phase value. An approximation detection portion 8a determines whether the first and second center phase values are approximate or not and outputs an approximation detection pulse when they approximate.

Abstract: A transmitting device encodes an animated image by detecting a difference between one image frame and a reference image frame, then transmits the encoded image to a receiving device by a radio line at high efficiency.