RADIO COMMUNICATION BASE STATION APPARATUS AND SYNCHRONIZATION CHANNEL SIGNAL TRANSMISSION METHOD
Provided is a base station capable of searching cells of different frequencies without losing a opportunity of data communication by effectively performing SCH data transmission. The base station ( 100 ) includes: an encoding unit ( 101 ) for encoding SCH data; a modulation unit ( 102 ) for modulating the encoded SCH data; a transmission timing setting unit ( 103 ) for setting the transmission timing of the SCH data; encoding units ( 104 - 1 to 104 -N) for encoding user data (# 1 to #N), modulation units ( 105 - 1 to 105 -N) for modulating the encoded user data (# 1 to #N); and an IFFT unit ( 106 ) for mapping the SCH data and the user data (# 1 to #N) to sub carriers (# 1 to #K) and performing IFFT to generate an OFDM symbol. The transmission timing setting unit ( 103 ) sets the transmission timing of the SCH data so that, for example, the SCH data transmission cycle and the frame cycle are relatively prime, i.e., the maximum common multiple of them is 1.
1 . A radio communication base station apparatus comprising:
a setting section that sets a transmission timing for a synchronization channel signal in one of a plurality of subframes forming a frame; and
a transmitting section that transmits the synchronization channel signal at the transmission timing set in the setting section,
wherein the setting section changes over time, a subframe in which the transmission timing is set in the plurality of subframes.
2 . The radio communication base station apparatus according to claim 1 , wherein the setting section periodically changes the subframe, in which the transmission timing is set in the plurality of subframes.
3 . The radio communication base station apparatus according to claim 1 , wherein the setting section changes every frame, the subframe in which the transmission timing is set in the plurality of subframes.
4 . The radio communication base station apparatus according to claim 1 , wherein the setting section sets the transmission timing such that a transmission cycle of the synchronization channel signal is coprime with a frame cycle.
5 . The radio communication base station apparatus according to claim 1 , wherein the setting section sets the transmission timing such that a transmission cycle of the synchronization channel signal is coprime with one Nth (N is a natural number) of a frame cycle.
6 . The radio communication base station apparatus according to claim 1 , wherein the setting section sets the transmission timing such that a transmission cycle of the synchronization channel signal equals to N-fold (N is a natural number) a cycle coprime with one Nth of a frame cycle.
7 . The radio communication base station apparatus according to claim 1 , wherein the transmitting section further transmits a report signal that reports the transmission timing set in the setting section to a radio communication mobile station apparatus.
8 . The radio communication base station apparatus according to claim 7 , wherein:
the synchronization channel signal is comprised of a first synchronization channel signal and a second synchronization channel signal; and
the transmitting section transmits the report signal using the second synchronization channel signal.
9 . The radio communication base station apparatus according to claim 1 , wherein the setting section further sets the transmission timing by changing the transmission cycle for the synchronization channel signal between a frequency division duplex system and a time division duplex system, and.
10 . A synchronization channel signal transmission method that sets a transmission timing for a synchronization channel signal in one of a plurality of subframes forming a frame and transmits the synchronization channel signal at the set transmission timing, the synchronization channel signal transmission method comprising changing over time, a subframe in which the transmission timing is set in the plurality of subframes.