Patent ID: 8023585
Filing Date: 2011-09-20
Classification: H04L

Abstract:
1. A transmitting apparatus for 4-value FSK modulation for transmitting data using four symbol values, the transmitting apparatus comprising: a dividing part supplied with original data arranged in order from one with highest importance, which comprises first data and second data after the first data and for dividing the first data, the first data being protected and having a predetermined number of higher order bits, the second data not being protected into first bit data in a unit of one bit and the second data into second bit data in a unit of two bits; a communication path quality decision part for deciding quality of an environment in a communication path; a bit adding part configured to add to each of the first bit data as a higher bit a redundant bit or an additional data bit associated with the original data to be transmitted, the redundant bit being predetermined so that the first bit data added with the redundant bit corresponds to any one of specific two symbol values, an interval between the specific two symbol values being largest of the four symbol values, to create encoded data in a unit of two bits, and to encode the second bit data in a unit of the divided two bits, wherein if it is decided by the communication path quality decision part that the quality of the communication environment is low, the redundant bit is added to the first bit data, while if it is decided that the quality is high, the additional bit data is added to the first bit data to create the encoded data; and a modulating part for performing modulation on the basis of the created encoded data to create and output a modulated signal.