Kabushikikaisha Kenwood

Jvc Kenwood Corporation

Taichi Majima

There are provided a transmission and reception device having a function for correcting a data error in a communication path. In the transmission device, a redundant bit addition unit adds a redundant bit to each data bit which has been divided by one bit by a division unit; and an interleaver performs interleave. The transmission device transmits a signal which has been subjected to FM modulation by an FM modulation unit. In the reception device, a symbol decision unit performs a symbol decision at a Nyquist point for a signal which has been FM-demodulated by an FM demodulation unit; a bit conversion unit performs bit conversion according to the result of symbol decision; and a frame recovery unit deletes the redundant bit added by the redundant bit addition unit of the transmission device, from the bit string de-interleaved by a de-interleaver. Thus, it is possible to surely perform an error correction with a simple configuration even when the communication state is not in a preferable environment.

Device and method for correcting a data error in communication path

Both a pre-word (PW) and a sync word (SW) are used to establish a synchronization or only the sync word (SW) is used to establish a synchronization in accordance with an operational status related to the synchronization in a mobile wireless communication apparatus. For example, during an initial synchronization with a control channel () being received, both the pre-word (PW) and the sync word (SW) are used to establish a synchronization when a calculation result in a synchronization calculating part exceeds a predetermined threshold value only once. During an initial synchronization with a direct communication channel () being received, both the pre-word (PW) and the sync word (SW) are used to establish a synchronization when the calculation result exceeds the predetermined threshold value once; or alternatively, only the sync word (SW) is used to establish a synchronization when the calculation result successively exceeds the predetermined threshold value twice. According to the present invention, the sync word is shortened so as to quickly establish a communication link, and the sync detection can be performed with high precision.

Mobile wireless communication apparatus, wireless communication apparatus and communication processing method

A multiplication value decision unit () decides a multiplication value which is a positive value or a negative value corresponding to a bit value of each bit contained in a binary bit string constituting a scramble pattern generated in a pattern generation unit (). A multiplication processing unit () multiplies symbol data representing each symbol value in the symbol data string formed by the multinary symbol containing a predetermined pair of a positive value and a negative value having an identical absolute value, in the value area, by the multiplication value decided by the multiplication value decision unit (). Here, the multiplication processing unit () successively executes the multiplication between the symbol data for one symbol and the multiplication value decided corresponding to the bit value of the one bit contained in the scramble pattern until the number of symbols expressed by the symbol data string is reached. The present invention scrambles the data string by a simple operation and performs scramble by a simple processing even when the function channel content is changed.

Scrambler, scramble processing method, and program

A soft decision device and method for obtaining a soft decision value as a value expressing a probability as near the actual probability as possible by simple processing. The soft decision device and method are used to output a soft decision value for each bit of each symbol used for decoding the each symbol as a value corresponding to the function value obtained by applying a predetermined function for each bit to the sampled value of the each symbol according to the demodulated signal such that the probability distribution of the sampled value in each symbol point is the Gauss distribution. The function for each bit is approximated to a curve expressing the probability that each bit is 1 or 0 for the sampled value of each symbol of the demodulated signal and defined by using a quadratic function.

Soft decision device and soft decision method

In a mobile telephone terminal at the transmitting end, voice data to be transmitted are sequentially inputted, and it is determined whether the inputted voice data are silent. The voice data regarded as silent voice are replaced by group numbers, while the voice data indicative of sonant voice as well as the group numbers as replaced are transmitted by wireless. On the other hand, in a mobile telephone terminal at the receiving end, the signals transmitted by wireless are received, and the voice data and group numbers of the received signals are discriminated. The voice data are reproduced as they are, while the group numbers are reproduced as silent, and further processings based on the group numbers are executed. This allows predetermined data to be repetitively transmitted with a high efficiency without degrading communication quality very much. This also facilitates a follow-up participation in a group call.

Communication method, transmitting method and apparatus, and receiving method and apparatus

A bit adding part acquires RSSI as measured by an RSSI measuring part, and adds '1' to each bit of protected audio data of an audio vocoder, if the acquired RSSI is smaller than a predetermined threshold value. If the acquired RSSI is equal to or greater than the predetermined threshold value, the bit adding part adds the bits of additional data to the respective bits of the protected data of the audio vocoder. A frame recovery part separates upper and lower order bits of deinterleaved data, and determines, based on CRC, whether eight data parts as obtained by combining the lower order bits as separated are valid. If so, the frame recovery part combines the eight data parts as the additional data to recovery additional information. In this way, additional data can be efficiently transmitted, while error correction being performed in accordance with communication environment.

Apparatus and method for transmitting or receiving data

There is disclosed a base band signal generation device and others for processing transmission data so that a reception side can restored the data without recognizing whether the data has been subjected to a processing and transmitting the data with an appropriate efficiency corresponding to the communication quality. A transmission device T judges the communication quality of a transmission path L. When the communication quality is preferable, a four-value FSK symbol is generated from the bit of the most significant part of the encoded voice data and the bit of the least significant part. When the communication quality is not preferable, a four-value FSK symbol is generated from the bit of the most significant part of the encoded voice data and a redundant bit of '0'. However, a symbol containing a redundant bit is set to the maximum value or the minimum value of the four values which the symbol value may have. Moreover, each bit of the encoded voice data has a value '0' when indicating that no component corresponding to the bit is present.

Device and method for generating a base band signal and program causing computer to execute the method

A device and method for effectively judging a communication quality in a communication system and a program used for the judgment. A communication device generates a four-value FSK symbol by adding a redundant bit to a bit of the most important part of encoded audio data. The symbol containing the redundant bit is set so that the symbol value is the maximum value of the minimum value of the four values which may be obtained. A reception device R receives the FSK modulation wave, restores the symbol, counts the number of redundant bits contained in the restored symbol and having incorrect values, decides whether to perform a bad frame masking process and what kind of bad frame masking process is to be performed, and executes the decided process. Thus, it is possible to accurately or rapidly judge the communication quality with a simple configuration.

Device and method for judging communication quality and program used for the judgment

An effective random access control can be performed with a high throughput. A base station () communicates with mobile stations () by use of slotted ALOHA system. An offset time of 1.5 frames is established between upstream and downstream communication frames. If any of the upstream communication frames is available, the base station () notifies a transmission permission signal (I) by use of the corresponding downstream frame. If having data to be transmitted, a mobile station () in a reception state receives the transmission permission signal (I), switches itself into a transmission state, and transmits one frame of leading data by use of the upstream frame. If permitting continuous transmission of data following the leading data, the base station () transmits a continuous transmission permission information (P) to that mobile station (), and transmits a transmission inhibition signal (B) to the other mobile stations () during that continuous transmission. When receiving the continuous transmission permission information (P), that mobile station () places itself in a transmission mode, and transmits the following data by use of a plurality of continuous frames of the upstream communication frames.

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Yokohama, Japan

Taichi Majima