Transmitting and receiving devices in cellular system
In a multi-carrier cellular system, a second synchronization code (a Walsh code or a GCL series code) mapped on a second synchronization channel is used as a signal for specifying in which cell of the base station a mobile station terminal device itself is. A signal transmitted from the base station to the mobile station terminal device is mapped in a radio frame having two-dimensional extension in frequency and time directions. When mapping a certain series number of the second code for specifying a cell or a cell group on the radio frame as the second synchronization channel, phase rotation or circular shift in which one radio frame is one cycle is applied to the second synchronization code. On the receiving side, the head timing of the radio frame is known by knowing the phase rotation angle or the amount of circular shift of the second synchronization code.
1. A transmitting device comprising:
processor circuitry configured to map each of a plurality of codes on a respective one of a plurality of synchronization channels, the codes being given values of initial offsets of phase rotation, and being different from each other, each of the plurality of codes undergoing circular shifting in a frequency domain, the circular shifting occurring by a shift amount that depends on a position within a radio frame at which each of the plurality of codes is mapped on a respective one of the plurality of synchronization channels, wherein one frequency shift cycle is completed within one radio frame; and
a transmitter that transmits a signal put in a radio frame in which the plurality of synchronization channels are multiplexed in a time direction.
2. The transmitting device according to claim 1 , wherein each of the codes is circularly shifted by a given amount of a circular shift according to a position of each of the codes in the radio frame.
3. The transmitting device according to claim 1 , wherein each of the codes is a different sequence generated by shifting a given code.
4. The transmitting device according to claim 1 , wherein each of the codes is a combination of codes whose sequences are different.
5. The transmitting device according to claim 1 , wherein each of the codes is a different sequence generated by a same processing circuit.
6. The transmitting device according to claim 1 , wherein each of the codes is used to specify a cell or a cell group in a cellular system.
7. A communication system comprising:
a receiving device; and
a transmitting device that puts a signal in a radio frame in which a plurality of synchronization channels are multiplexed in a time direction and transmits to the receiving device, wherein
the transmitting device includes,
a transmitter configured to map each of a plurality of codes on a respective one of a plurality of synchronization channels, the codes being given values of initial offsets of phase rotation, and being different from each other, each of the plurality of codes undergoing circular shifting in a frequency domain, the circular shifting occurring by a shift amount that depends on a position within the radio frame at which each of the plurality of codes is mapped on a respective one of the plurality of synchronization channels, wherein one frequency shift cycle is completed within one radio frame and transmitting the codes.