摘要:
A transmission power control device is provided that includes: a transmission loss calculator that calculates a transmission loss in the electric wave transmission path between a mobile station and each base station; and a transmission power control information determiner that determines which transmission power control information is to be used in a transmission power control operation at the mobile station, based on transmission power control information transmitted from each base station to the mobile station and the transmission loss in the transmission path between the mobile station and each base station calculated by the transmission loss calculator. This transmission power control device may further include an autonomous controller that increases transmission power from a current value in accordance with predetermined characteristics, regardless of transmission power control information from another communication device, when reception signal quality has become lower than a predetermined quality level. With this structure, after synchronization with a signal from the base station is established at the mobile station, the transmission power is controlled to increase from the initial value in accordance with the predetermined characteristics, regardless of the transmission power control information transmitted from the base station.
摘要:
An effective data multiplexing method wherein an error correction ability is exerted at the maximum so that data transmission quality is improved and a data transmitting method in which an interleaving process applicable to data transmission using interpolation pilot signal is performed are provided. The data multiplexing method includes the steps of: coding input data for each input channel; multiplexing said data which is coded; performing an interleaving process on said data which is multiplexed; and outputting said data. In the data transmitting method, when an interleaving process is performed, an interleaver is used in which the number of columns of the interleaver is twice as many as the number of slots of a frame.
摘要:
An effective data multiplexing method wherein an error correction ability is exerted at the maximum so that data transmission quality is improved and a data transmitting method in which an interleaving process applicable to data transmission using interpolation pilot signal is performed are provided. The data multiplexing method includes the steps of: coding input data for each input channel; multiplexing said data which is coded; performing an interleaving process on said data which is multiplexed; and outputting said data. In the data transmitting method, when an interleaving process is performed, an interleaver is used in which the number of columns of the interleaver is twice as many as the number of slots of a frame.
摘要:
A DS-CDMA transmission method capable of improving the accuracy of channel estimation using pilot symbols by eliminating cross-correlation between pilot symbols inserted into code channels in CDMA multiplexing carrying out fast signal transmission. In each frame assembler, the pilot symbols, which are used for channel estimation for coherent detection, are inserted into coded information data on code channels at fixed intervals, and then the data is modulated by the modulator. The modulated data symbols in each code channel from the modulator are spread by the spreading modulator, the pilot symbols are spread using a spreading code, whereas the information symbols are spread using different spreading codes assigned to respective code channels. The spread signals of the code channels are summed up by the adder to be transmitted.
摘要:
A transmission method for implementing variable rate transmission. Part of the baseband processing of a transmitter based on a CDMA transmission scheme is described. A transmitted information sequence in the form of a digital signal is phase modulated by a phase modulator 105. An orthogonal code generator 101 selects, in response to rate information of the transmitted signal, the orthogonal code to be generated. The bit rate of the orthogonal code the orthogonal code generator 101 generates is double the maximum transmission rate. The modulated transmitted signal is multiplied by the orthogonal code corresponding to the rate information with a multiplier 103. The transmitted signal, which is multiplied by the orthogonal code corresponding to the rate information, is further multiplied by a spreading code sequence with a multiplier 104 to be spread into a CDMA signal, and is transmitted under power transmission control based on the rate information. A receiving side can detect the rate without information about the transmission rate.
摘要:
An error rate of received signal is measured by a received signal error measuring unit 32, and a target SIR is changed by a target SIR decision unit using the error rate. It is also possible to detect error rate of received signal in an unit of frame using a CRC signal of a frame. It is further possible to detect error rate of received signal by detecting errors of known pilot signals inserted in a constant interval.
摘要:
Datapath elements 1.sub.1 to 1.sub.N can exchange data respectively with local memories 2.sub.1 to 2.sub.N through data buses 6.sub.1 to 6.sub.N, so that parallel operations can be performed. The data bus 6.sub.1, which is connected with one datapath element 1.sub.1, can be connected with the other data buses 6.sub.2 to 6.sub.N through an interconnection network 5, so that by activating one datapath element 1.sub.1 only, data exchange can be made with all of the local memories 2.sub.1 to 2.sub.N through the data buses 6.sub.1 to 6.sub.N and the interconnection network 5. Thus, the multiple datapath elements can perform the parallel operations with being related with the multiple local memories: and a simple configuration is employed such that one datapath element can access to any one of the local memories.
摘要:
A data transmission method according to the present invention includes the steps of: (A) adding a first CRC code to transmission data; (B) dividing the transmission data to which the first CRC code has been added into a plurality of encoded bit sequences; (C) adding a second CRC code to at least one of the divided encoded bit sequences; (D) performing error correction encoding processing on the encoded bit sequences; and (E) transmitting the encoded bit sequences on which the error correction encoding processing has been performed.
摘要:
In this invention, a channel estimation value of data symbols of a data channel is calculated by weighting and averaging pilot symbols in a parallel time multiplexing method. Also, a channel estimation value of data symbols during each data symbol interval is calculated by dividing data symbols in a slot into a plurality of data symbol intervals, selecting pilot symbols suitable for calculation of a channel estimation value of data symbols during each data symbol interval and weighting and averaging that pilot symbols. Also, a fading frequency is detected based on an inner product value of pilot symbols. Weighting factors are changed based on the detected fading frequency. Also, a channel estimation value is calculated by weighting and averaging pilot signals using a plurality of weighting sequences. The calculated channel estimation value is used to demodulate received data. The output data with the highest quality is selected by judging reliability of these plurality of demodulated data. It is also possible to select some weighting sequences based on the result of the reliability judgment of the demodulated data for predetermined period of time. In this case, after the selection, demodulation is performed by using these selected weighting sequences only.
摘要:
A communication method for continuously receiving multiple pieces of data from a radio base station via a radio link. The method includes determining whether or not any one of the multiple pieces of data is lost; and making an instruction to the radio base station to increase the transmission power of the radio base station when it is determined that any one of the multiple pieces of data is lost, the instruction being made before a retransmission timing when the transmitter retransmits the lost data piece.