摘要:
An encoder includes: a precoder for encoding an input information object according to a preset encoding scheme and storing the encoded information object in a precoder buffer; a sample number/address generation unit for generating a sample number of each sample and an address, which corresponds to each bit of each sample and the address of the precoder buffer; a multiplexer for selecting a bit of the precoder buffer corresponding to the address generated by the sample number/address generation module; a sampling buffer for storing a bit of each sample output from the multiplexer; a control packet generation module for generating a control packet including information on the sample number generated by the sample number/address generation module; a packet assembling unit for assembling the sample stored in the sampling buffer with the control packet generated by the control data generation module; and a modulation module for modulating the packet output from the packet assembling unit into a sound signal according to a preset scheme.
摘要:
A packet multiplexing apparatus is presented for multiplexing packets to be transmitted from a number of user facilities to a local service node in such a way to assure equal access to one output port for all the users. The apparatus is provided with input ports (1-0~1-(N-1)) for inputting a packet in a respective input port; buffer memories (3-0~3-(n-1)) provided for each input port for temporary storage of a packet; an output signal transmission circuit (4) for retrieving a packet from each buffer memory in a specific sequence; an output port (2) for transmitting packets output from the output signal transmission circuit; and a retrieval sequencing section (10 or 20 or 30) for controlling the specific sequence by changing a retrieving order of packets from buffer memories for each complete round of packet retrieval so that a frequency of the retrieving order for each input port is uniformly shared by the input ports.
摘要:
A message communication system employing one or more centralized communication stations transmitting messages through Earth orbit relay satellites to mobile receivers utilizing Time Division Multiplexed (TDM) communication signals having signal time frames divided into a series of transmission channels. A predetermined number of the channels are designated as address channels with the remainder being used for data transfer. Information transmitted on the address channels is used by receivers to determine both the presence of a message and its corresponding data transmission channel. Each system receiver scans, and tracks only the communication signal address channels until a message addressed to that receiver is detected, at which time the selected receiver changes channels to the designated data channel for reception of the message. Thus, demodulation of the entire communication signal is not required and processing time and power is reduced for the typical waiting condition when messages are not being received. While a message is being received only a portion of the communication signal need to be received, demodulated and decoded. The decoded message is then displayed on a display screen or similar device for the recipient.
摘要:
Data having an ID code attached thereto is transferred via a network line (16). The ID code is detected by an ID code detection circuit (30) and data is received by a data receiving circuit (31). An ID code (RX ID) detected by the ID code detection circuit (30) and an ID code previously stored in an ID comparing register (32) are compared with each other by a comparator circuit (33). Predetermined ID codes corresponding to an engine rotation speed and car speed, for example, are stored in the ID comparing register (32). A masking circuit for masking one or more bits of the ID code is provided in the comparator circuit (33). The switching state of a switch (34) for controlling the transfer of data received by the data receiving circuit (31) is controlled according to a comparison output of the comparator circuit (33). when the ID codes are coincident with each other, the switch (34) is turned on, causing data received by the data receiving circuit (31) to be transferred to a CPU (18). A plurality of electronic instruments (10) can be selected by use of a single ID code by masking at least one bit of the ID code by means of a masking circuit.
摘要:
Data having an ID code attached thereto is transferred via a network line (16). The ID code is detected by an ID code detection circuit (30) and data is received by a data receiving circuit (31). An ID code (RX ID) detected by the ID code detection circuit (30) and an ID code previously stored in an ID comparing register (32) are compared with each other by a comparator circuit (33). Predetermined ID codes corresponding to an engine rotation speed and car speed, for example, are stored in the ID comparing register (32). A masking circuit for masking one or more bits of the ID code is provided in the comparator circuit (33). The switching state of a switch (34) for controlling the transfer of data received by the data receiving circuit (31) is controlled according to a comparison output of the comparator circuit (33). when the ID codes are coincident with each other, the switch (34) is turned on, causing data received by the data receiving circuit (31) to be transferred to a CPU (18). A plurality of electronic instruments (10) can be selected by use of a single ID code by masking at least one bit of the ID code by means of a masking circuit.
摘要:
Dans le système, la station émettrice diffuse, sous forme de paquets, des données numériques provenant de plusieurs voies. Chaque paquet comporte un préfixe contenant, outre des signaux de synchronisation classiques (R1, R2, B) et de code d'identification de voie (A1, A2, A3), un signal d'indice de continuité de paquet (lC) et une information sur la structure du paquet (SP). Chaque voie peut correspondre à une pluralité de sources. Les données de source sont arrangées en groupe de données formés d'une série de blocs de données. Chaque bloc forme le champ de données d'un paquet. Le premier bloc de chaque groupe comporte un en-tête de groupe formé d'octets définissant le type de groupe (TG), l'indice de continuité de groupe (C), le nombre de blocs du groupe qui suivent le premier bloc (T1, T2) et la taille du dernier bloc du groupe (F1, F2). Le préfixe de chaque paquet comprend, en outre, l'information (B1) indiquant si le bloc du paquet est le premier bloc d'un groupe ou non. L'en-tête comporte encore une information de catégorie de traitement (TG) indiquant vers quel circuit de traitement du récepteur le groupe doit être dirigé. Elle peut encore comporter une information (R) indiquant le nombre de fois que le groupe concerné sera encore répété. Le préfixe de paquet comprend une information (S) indiquant le nombre d'octets formant le suffixe de détection d'erreurs et de correction.
摘要:
One of the transmission facilities (101) of a TASI system is used as an order wire, via which channel signalling information and assignment information are transmitted. Signalling information is transmitted periodically in frames on the order wire for only some of the channels (100), connected to the system, at any one time. Accordingly, the assignment information consists of both channel-to-facility assignment information, relating to the assignment of channels to the other facilities, and channel signalling assignment information, relating to the assignment of channels to signalling bit time channels in the frames on the order wire. One assignment can be transmitted in each frame, and frames not used for transmitting assignment information can be used for transmitting commands and messages. The system avoids the need to transmit multi-tone signals preceding speech bursts on the transmission facilities and avoids lengthy delays in the transmission of channel signalling information.
摘要:
Le dispositif d'insertion de données (30) impose aux paquets un format fixe ayant une longueur prédéterminée L de la zone utile et structure les données suivant une trame de longueur fixe 1 qui est un sous-multiple de L. Un circuit (35) insère dans le préfixe de chaque paquet ou dans chaque trame un mot d'indice de continuité qui est incrémenté d'une unité à chaque paquet ou trame transmis ou diffusé. Le récepteur (20) de l'installation comporte des moyens (26) de détection de rupture d'incrémentation. Il peut comporter des moyens de création de données supplémentaires se substituant aux données manquantes en cas de perte d'un paquet.