摘要:
The present invention relates to a radio communication system comprising base stations and mobile stations and a method for controlling transmission power in the system where the base station is able to perform multi-point transmission for transmitting the same signal to a plurality of the mobile stations. In the present invention, the mobile station targeted for the multi-point transmission provides the base station of an increase request or a decrease request of the transmission power by respectively transmitting or not transmitting a predetermined signal to the base station.
摘要:
A radio communication system for carrying out communications between radio stations by modulating a plurality of signal sequences to be transmitted and received into at least one frequency channel assigned to each of a plurality of cells is formed by a channel mapping means for rearranging for each cell a plurality of frequency channels assigned with respect to each cell, and newly assigning particular frequency channels as a transmission and reception band of said signal sequences, and a bandwidth control means for controlling a bandwidth of said assigned frequency channel according to a propagation state of said assigned frequency channel.
摘要:
An OFDM transmitter is configured to perform a peak reduction process on a signal sequence to be transmitted in a stepwise manner to transmit a peak processed transmission signal. The OFDM transmitter includes a dividing inverse fast Fourier transform unit (104) configured to divide the signal sequence to be transmitted into N signal sequences (N>2) and perform inverse fast Fourier transform on each of the divided signal sequences to output N time signal sequences; a threshold control unit (106) configured to determine at least two threshold values (Cth) used in the stepwise peak reduction process; and a first peak reduction processing unit (1201) configured to determine a first cyclic shift to be applied to one of the time signal sequences based on a first one of the threshold values, produce a first cyclically shifted signal sequence according to the first cyclic shift, and output a first peak processed signal sequence based on the first cyclically shifted signal sequence. The first cyclic shift is determined such that an exceeding power level over the first threshold value in the first peak processed signal sequence becomes the minimum.
摘要:
A receiver for mobile communication includes a wireless scheme parameter storing unit (23) configured to store a plurality of characteristics of multiple wireless schemes, a wireless scheme estimation unit (22) configured to estimate one of the characteristics of a currently used wireless scheme from a received signal and select one of the wireless schemes corresponding to the estimated characteristic from the wireless scheme parameter storing unit, and a demodulator (24) configured to demodulate the received signal based on the selected wireless scheme.
摘要:
A transmitter used in the multiband environment includes a frequency allocation unit (106) configured to select and allocate a frequency band that satisfies a user QoS from among multiple separate frequency bands currently available for the user, a parameter determination unit (111) configured to determine a transmission parameter required for signal transmission based on the allocated frequency band, and a multi-user scheduling control unit (110) configured to determine a transmission schedule for multiple users taking into account the frequency bands allocated to the multiple users.
摘要:
A shared frequency transmitter for use in a network environment where transmitters and receivers of plural radio communication systems in which the same frequency is used exist is disclosed. The shared frequency transmitter includes (a) a communicating unit configured to detect peripheral transmitters existing in a peripheral area, and to exchange information with the detected peripheral transmitters; and (b) a signal generating unit configured to generate a transmit signal by applying an interference cancellation technique based on the information obtained through the exchange of information.
摘要:
A communication node that relays signals between a source node and a destination node includes (a) a first unitary matrix calculation unit configured to calculate a first unitary matrix based on a first channel between the source node and the relay node, (b) a second unitary matrix calculation unit configured to calculate a second unitary matrix based on a second channel between the relay node and the destination node, (c) a transformation matrix estimation unit configured to estimate a transformation matrix based on a triangular matrix derived from QR decomposition of the first and/or second channel matrix, (d) a relaying signal generator configured to generates a relaying signal by multiplying a received signal by at least one of the first unitary matrix, the second unitary matrix, and the transformation matrix, and (e) a transmission unit configured to transmit the relaying signal to the destination node.
摘要:
A radio transmitter adopting the OFDM scheme is disclosed. The radio transmitter includes an amplitude measuring part for measuring the amplitude of a transmission signal on which inverse Fourier transform has been performed; a power control part for outputting, based on the result of the measurement, control signals each for adjusting the amplitude of a signal on which inverse Fourier transform has not been performed, each signal corresponding to one of plural sub-carriers; and multiple multiplying parts each for multiplying the amplitude of the signal by a multiplying number indicated by the control signal. The power control part outputs the control signal based on a product of a signal pf(n) obtained by performing Fourier transform on an output of the amplitude measuring part and the signal sf(n).
摘要:
A signal separator for separating multiple signals contained in a received signal from each other based on a replica of the received signal is provided. The signal separator comprises a sampling unit configured to sample the received signal at a prescribed sampling timing; an index output unit configured to monitor sampling counts of the sampling unit and output an index signal representing a remainder of a division dividing the sampling counts by a sampling number per a prescribed time period to group the sampled signals; a coefficient-variable filter configured to generate and output a replica of the received signal based on a channel estimation value and a signal point candidate, at least one of the channel estimation value and the signal point candidate being generated according to the index signal; a subtractor configured to subtract the replica from the sampled signal and output a subtraction result as a residual signal; and a maximum likelihood sequence estimator configured to estimate a sequence for each of the multiple signals based on the residual signal, taking into account signal state transition, and output the estimation result at a signal output timing determined by the index signal.
摘要:
A recording medium comprises an ink-receiving layer comprising a pigment and an alkali-process gelatin, wherein the alkali-process gelatin has no sol-gel reversibility in an environment of room temperature and has a weight average molecular weight within the range of from 50,000 to 150,000. A coating aqueous dispersion comprises water and has dispersed therein a pigment and the alkali-process gelatin. A process for producing a recording medium comprises the steps of coating on a support at room temperature the coating aqueous dispersion and drying the resulting coating at a high temperature of 80.degree. C. or above. An image forming method comprises ejecting minute droplets of an ink from fine orifices to apply the ink droplets to the recording medium to make a print. A printed material comprises the recording medium.