Abstract: A wireless communication apparatus in a wireless communication system transmits power-control information on a power-control channel, separate from the traffic channels of the wireless communication system. In a code division multiple access system, the power-control channel has a separate spreading code. The power-control channel provides a steady flow of power-control information, even when traffic channels are used only intermittently.

Abstract: A mobile radio communication system for communicating between a base station and a mobile station by means of frames, each frame including a header and data. The mobile station includes a transmission number provider which provides a first transmission number to a first frame to be transmitted to the base station, and a transmission number extractor which extracts the first transmission number indicated in a header pattern of a second frame transmitted by the base station. The base station includes a reception number detector which detects the first transmission number included in the first frame transmitted by the mobile station, and a header provider which provides a header pattern corresponding to the first transmission number of the second frame. The mobile station retransmits the first frame when the mobile station does not receive the first transmission number indicated in the header pattern of the second frame.

Abstract: A high pressure fuel pump for an internal combustion engine having a cylinder, a plunger slidably fitted in the cylinder and a seal mechanism for blocking fuel leakage from an end of a sliding portion between the cylinder and the plunger and also for preventing an lubricant for a driving mechanism of the plunger from entering into the cylinder from the end of the sliding portion of the cylinder and the plunger. A holder surrounding the end of the sliding portion of the cylinder and the plunger is provided. The seal mechanism comprises two mutually independent seal devices mounted with a specific spacing in a longitudinal direction from the end of the sliding portion of the cylinder and the plunger along a circumference of the plunger. The two seal devices are held on the circumference of the plunger by the holder surrounding the end of the sliding portion of the cylinder and the plunger while keeping the specific spacing.

Abstract: A radio communication system such as a mobile communication system is provided which establishes communications between a main transmission unit and sub-transmission units. The main transmission unit transmits to the sub-transmission units simultaneously a frame including a data slot to which paging data on a call made by one of the sub-transmission units to another is added and a preamble to which a bit stream to be subjected to double spreading is added for informing the sub-transmission units of a call request. Each of the sub-transmission units includes a reproducing circuit reproducing the paging data of the received frame. The reproducing circuit is allowed to operate only when the preamble of the received frame indicates the presence of the paging data.

Abstract: In a mobile radio communication system, a transmitter of a base station transmits broadcast information to receivers of mobile stations in the form of frames. The transmitter produces a long frame composed of a plurality of frames each including a first bit sequence and part of the broadcast information following the first bit sequence, and a second bit sequence located at the head of the long frame. Each of the first bit sequences and the second bit sequence is used for establishing synchronization between the transmitter and each of the receivers. Upon receipt of the long frame from the transmitter, the receiver establishes synchronization of the long frame based on the foregoing second bit sequence.

Abstract: A convolutional coder performs rate 1/N and 1/M convolutional coding (M<N). The convolutional coder includes a convolutional code generator, a parallel/serial converter, a rate indicator, and a selector. The rate indicator indicates either rate 1/N or 1/M convolutional coding. The selector provides the N convolutional coding bits for rate 1/N convolutional coding. Also for the rate 1/M convolutional coding, the selector provides M convolutional coding bits generated by M generator polynominals common to rate 1/N and 1/M convolutional coding and nullifies (N−M) convolutional coding bits generated by the other (N−M) generator polynominals for the rate 1/N convolutional coding. A Viterbi decoder performs rate 1/N convolutional decoding and includes a rate indicator and a data converter. The rate indicator detects a 1/N or 1/M convolutional coding rate from a received signal (M<N).

Abstract: This invention uses a plurality of encoding methods for communication between a base station BS and a mobile station MS. When the base station BS encodes a transmission signal, a suitable encoding method is selected from a plurality of encoding methods based on traffic conditions, the peripheral environment of the mobile station MS, etc. The base station BS notifies which encoding method has been used to the mobile station MS. The mobile station MS recognize the encoding method used by the base station BS from the information notified from the base station BS. The mobile station MS decodes a receive signal using a method corresponding to this encoding method.

Abstract: A CDMA transmitter-receiver capable of varying a transmission rate of a voice signal coded on a sample by sample basis. A voice encoder encodes, on a sample by sample basis, a voice signal to be transmitted. An information distributor divides a coded digital signal, and supplies the divided parts to an error correcting encoder and an interleaver in accordance with transmission rate information so that the number of bits to be subjected to the error correcting coding varies in response to a transmission rate the transmission rate information indicates, thereby varying the total number of transmitted bits. Digital signals with and without subjected to the error correcting coding are transmitted to a party through components from the interleaver to an RF transmitting stage. A transmission power controller controls the transmission power of an RF transmitted signal output from the RF transmitting stage in response to the transmission rate information fed from the controller.

Abstract: A mobile communication system includes a base station and mobile stations divided into a plurality of groups. A radio communication device 10 at the base station spreads framed control information using a spreading code, and then transmits it via a control channel to the mobile stations. The radio communication device 10 includes a header spreading code generating section 16 which produces mutually different two spreading codes, and further includes a header adding section 17 which, using the mutually different two spreading codes, double-spreads information about allocation of an access right to corresponding one of the groups and adds the double-spread information as a frame header to a frame body representing the foregoing framed and spread control information.

Abstract: An intermittent transmission control system based on a TDMA system which involves a burst transmission, has a sound presence detector for detecting presence or absence of sound information to be transmitted on the basis of an aural signal input from a microphone; a switch unit for switching types of the burst transmission; and a call control processor for causing the switch unit to switch the types of the burst transmission in such a way that a normal burst transmission containing the sound information is performed if presence of the sound information is detected by the sound presence detector, whereas a reduced burst transmission containing time interval information of the burst transmission is performed if no burst transmission is performed for a predetermined time. The call control processor also causes the switch unit to switch the types of the burst transmission in such a way that the normal burst transmission containing Fast Associated Control Channel information is performed.

Abstract: A decoder which is adapted to receive a frame of coded data consisting of multiple slots including intra-frame position information indicating positions of the slots in the frame to decode the coded data, and which adaptively applies appropriate ones of plural error control methods depending on the position of the slots in the frame. An estimated value of the intra-frame position information of a current slot and a fixed amount of variation per slot of the intra-frame position information are generated in accordance with an estimated value of the intra-frame position information of an immediately preceding slot. Synchronization is established between a received value and the estimated value of the intra-frame position information. An error control method to be applied to the current slot in the synchronous state of the received value and the estimated value is determined in response to the estimated value of the intra-frame position information of the current slot generated.

Abstract: A convolutional code having identical initial and final states is decoded by using the Viterbi algorithm to trace a path starting from a first state and ending at a second state. If necessary, the trace is repeated, starting from the second state, provided the second state is not the same as the first state. The output result is then obtained from the second trace.

Abstract: An error detecting device and method for use when applying the Viterbi decoding to an inputted signal, when it is necessary to derive the number of errors included in a decoded signal. A value of a path metric derived upon the Viterbi decoding is read out and outputted as the number of errors. Two kinds of decoding devices, each reading out a value of a path metric and outputting this value as the number of errors, are provided for a sound signal and an FACCH signal. A signal is inputted to both devices for decoding, respectively. The numbers of errors derived from both devices are compared, and it is judged based on a result of the comparison, whether the inputted signal is the sound signal or the FACCH signal.

Abstract: A discriminating circuit stores a flag designating a received radio signal as belonging to a traffic channel, a control channel, or an unidentified channel. If the flag does not indicate the traffic channel, the discriminating circuit decodes the signal and detects errors on the assumption that the signal belongs to the control channel. The detected errors include convolutional code errors, which are detected by re-encoding the decoded signal, as well as errors in other types of codes. If the flag indicates that the channel is unidentified, a counter is incremented according to the paucity or absence of errors. When the counter reaches a threshold value, the flag is set to indicate the control channel.

Abstract: A bit error counter for a digital communication system has transmitter and receiver. The transmitter includes circuitry for convolution encoding of an input original signal and outputting a transmission signal. The receiver includes error correcting/decoding circuitry for inputting a reception signal corresponding to the transmission signal and outputting a decoded signal, and when an overflow occurs, for outputting an overflow signal. State monitoring circuitry is provided for receiving the overflow signal and issuing a switching instruction signal to a switch only when the overflow signal is received. The switch also receives the decoded signal and outputs at least one of a bit error rate or a number of errors when the switching instruction signal is received. The switch outputs the decoded signal when the switching instruction signal is not received.

Abstract: A decoder receives frames of data that have been block coded, then convolutionally coded, at a rate of multiple frames per block. As each frame is received, the decoder counts it, stores convolutional code path information, and updates metric values pertaining to the paths. Once per block of frames, the decoder selects a path having the best metric value, convolutionally decodes one block, detects errors from both the block code and path metric, and generates error information. From the error information, the decoder decides whether block synchronization has been acquired or lost, and clears, decrements, or sets the frame count accordingly. If synchronized, the decoder outputs the block and its error information, and updates the path memory in preparation to decode the next block. Otherwise, the decoder prepares to reacquire block synchronization.

Abstract: An equalizer including a channel estimator allowing a Viterbi algorithm processor to estimate transmitted symbols accurately, so that the impulse response of a transmission channel may not deviate from the correct one. The equalizer outputs an transmitted symbol sequence estimate having the largest path metric by correcting the channel impulse response by parameter coefficients of the LMS (Least Mean Square) or RLS (Recursive Least Square) algorithm, by compensating for phase fluctuations due to the frequency offset and phase jitter of received signals, or by using a sequence included in an intermediate portion of a TDMA (Time Division Multiple Access) frame format.

Abstract: Novel cephem compounds are provided which are useful for synthesizing cephamycin compounds useful as antibacterial agents. The novel compounds have the formula (I): ##STR1## wherein R.sup.1 represents a lower alkyl group and R.sup.2 represents an amino group which may be protected, in the salt thereof.

Abstract: A method and apparatus utilizing a core is located at a central portion of a molten metal storing portion in a vertical semi-continuous mold. The molten metal is poured into the molten metal storing portion, and casting takes place with the inner diameter of a solidified distal portion of the molten metal being controlled by a distal portion of the core. This approach provides a reliable method for the manufacture of high-quality hollow billets which are free from internal defects.

Abstract: Improved clarity and resistance to deterioration on heating of polyvinyl fluoride and vinyl chloride polymers is obtained by employing a stabilizer composition consisting essentially of (A) a heterocyclic nitrogen compound having as part of a 5 or 6 membered heterocyclic ring the group ##STR1## in which R is hydrogen, aryl, or alkyl having 1 to 12 carbon atoms, and X is oxygen or sulfur, and (B) one or more 1,2-epoxides, organic phosphites, or stannous tin, zinc, magnesium, aluminum, potassium, sodium, calcium, strontium, or barium salts of non-nitrogenous monocarboxylic acids having from 6 to 24 carbon atoms or hydrocarbon-substituted phenols having from about 10 to about 30 carbon atoms.