Patent ID: 8090000
Filing Date: 2012-01-03
Classification: H04B

Abstract:
1. A communication system for transmitting a transmission signal including: a plurality of transmitting devices; and one or more receiving devices, the transmission signal being transmitted between the transmitting devices and the one or more receiving devices, and the transmission signal being obtained by spreading a transmission data into components of a predetermined first number of frequency domains and components of a predetermined second number of time domains, wherein, in a pair formed by one or more of the transmitting devices and one or more of the receiving devices, the one (or each) of the plurality of transmitting devices comprises a signal transmission unit for sequentially spreading, based on a spread pattern including a plurality of first elements defined with respect to the components of the first number of frequency domains and components of the second number of time domains and arranged so as to spread transmission data to the components of the frequency domains and the components of the time domains, the transmission data to the components of the frequency domains and the components of the time domains at each predetermined time interval, and transmitting the transmission data as a transmission signal, and an updating unit for updating, based on the spread pattern received from the receiving device, the spread pattern used to spread the transmission data; and the one or more receiving devices comprises a receiving unit for receiving the transmission signal, an expansion unit for sequentially expanding the received transmission signal into a plurality of second elements defined with respect to components of the frequency domains whose number is a third number that is equal to or greater than the first number and components of the time domains whose number is a fourth number that is greater than the second number at each of the predetermined time intervals, a processing unit for sequentially performing a process using a plurality of first coefficients defined for each of the second elements on the second elements obtained as a result of the expansion at each of the predetermined time intervals, a generation unit for generating new first coefficients using the processed second elements and the plurality of first coefficients, a selection unit for selecting a second coefficient corresponding to the spread pattern from among the new first coefficients, a ratio calculation unit for calculating a value indicating a ratio of a peak value of a transmission signal obtained when the selected second coefficient is set as the spread pattern in the one (or each) of the plurality of transmitting devices to an average value of the transmission signal, a pattern generation unit for generating the selected second coefficient as a new spread pattern when the value indicating the ratio satisfies a predetermined condition or when all elements included in the selected second coefficient satisfy a predetermined condition, and a pattern transmission unit for transmitting the new spread pattern to the one (or each) of the plurality of transmitting devices.