Radio transmission device and radio communication method

A wireless transmitting apparatus comprising:

• a sequence length determining section configured to associate a constant amplitude and zero-autocorrelation code sequence of a common basic sequence length with a plurality of transmission bandwidths to which a reference signal is allocated, and to determine a basic sequence length associated with a transmission bandwidth indicated by acquired transmission bandwidth information;
• a sequence generating section configured to generate a constant amplitude and zero-autocorrelation code sequence associated with the determined basic sequence length;
• and
• a transmitting section configured to transmit the generated constant amplitude and zero-autocorrelation code sequence as a reference signal;
• and
• a cyclic extension and truncation processing section configured to perform one of cyclic extension processing and truncation processing on the constant amplitude and zero-autocorrelation code sequence of the basic sequence length, based on a number of cyclic extension and truncation symbols, wherein the sequence length determining section determines a difference between the transmission bandwidth and the basic sequence length associated with the transmission bandwidth, as the number of cyclic extension and truncation symbols,
• wherein the sequence length determining section determines a possible number of cyclic extension and truncation symbols that represents a maximum possible number of symbols subject to cyclic extension or truncation, so as to make equal a ratio between the possible number of cyclic extension and truncation symbols and the basic sequence length in the plurality of transmission bandwidths to which the reference signal is allocated.

A wireless transmission apparatus comprising:

• a sequence length determining section configured to associate a constant amplitude and zero-autocorrelation code sequence of a common basic sequence length with a plurality of transmission bandwidths to which a reference signal is allocated, and to determine a basic sequence length associated with a transmission bandwidth indicated by acquired transmission bandwidth information;
• a sequence generating section configured to generate a constant amplitude and zero-autocorrelation code sequence associated with the determined basic sequence length;
• and
• a transmitting section configured to transmit the generated constant amplitude and zero-autocorrelation code sequence as a reference signal;
• and
• a cyclic extension and truncation processing section configured to perform one of cyclic extension processing and truncation processing on the constant amplitude and zero-autocorrelation code sequence of the basic sequence length, based on a number of cyclic extension and truncation symbols, wherein the sequence length determining section determines a difference between the transmission bandwidth and the basic sequence length associated with the transmission bandwidth, as the number of cyclic extension and truncation symbols,
• wherein the sequence length determining section holds association relationships between a basic sequence length, a transmission bandwidth and a number of cyclic extension symbols on a per repetition factor basis, and determines, as a basic sequence length, a sequence length associated with a number of repetition factors of an integer close to a result of dividing a transmission bandwidth represented by a number of resource blocks by a repetition factor.

A wireless transmission apparatus comprising:

• a sequence length determining section configured to associate a constant amplitude and zero-autocorrelation code sequence of a common basic sequence length with a plurality of transmission bandwidths to which a reference signal is allocated, and to determine a basic sequence length associated with a transmission bandwidth indicated by acquired transmission bandwidth information;
• a sequence generating section configured to generate a constant amplitude and zero-autocorrelation code sequence associated with the determined basic sequence length;
• and
• a transmitting section configured to transmit the generated constant amplitude and zero-autocorrelation code sequence as a reference signal;
• and
• a cyclic extension and truncation processing section configured to perform one of cyclic extension processing and truncation processing on the constant amplitude and zero-autocorrelation code sequence of the basic sequence length, based on a number of cyclic extension and truncation symbols, wherein the sequence length determining section determines a difference between the transmission bandwidth and the basic sequence length associated with the transmission bandwidth, as the number of cyclic extension and truncation symbols,
• wherein the sequence length determining section holds association relationships between a basic sequence length, a transmission bandwidth and a number of cyclic extension symbols on a per repetition factor basis, and determines, as a basic sequence length, a sequence length of an integer close to a result of dividing a number of transmission subcarriers by a repetition factor, among sequence lengths available for the repetition factor of “1.”

A wireless communication method comprising:

• determining a basic sequence length of a constant amplitude and zero-autocorrelation code (CAZAC) sequence associated with a transmission bandwidth indicated by acquired transmission bandwidth information, according to an association relationship between the basic sequence length of the CAZAC sequence and a plurality of transmission bandwidths to which the CAZAC sequence is allocated;
• and
• generating a CAZAC sequence associated with the determined basic sequence length, wherein:
• the association relationship (i) provides a grouping of the plurality of transmission bandwidths to which the CAZAC sequence is allocated into a plurality of transmission bandwidth groups, each transmission bandwidth group comprising at least a first transmission bandwidth and a second transmission bandwidth, and (ii) defines a first prime number that is nearest to and less than the first transmission bandwidth and a second prime number that is nearest to and less than the second transmission bandwidth, the first prime number and the second prime number being different from each other, and
• when the acquired transmission bandwidth information indicates the first transmission bandwidth, the sequence length determining section is configured to determine the sequence length having the second prime number, as the basic sequence length of the CAZAC sequence.

A wireless reception apparatus comprising:

• a sequence length determining section configured to determine a basic sequence length of a constant amplitude and zero-autocorrelation code (CAZAC) sequence associated with a transmission bandwidth indicated by acquired transmission bandwidth information, according to an association relationship between the basic sequence length of the CAZAC sequence and a plurality of transmission bandwidths to which the CAZAC sequence is allocated;
• a cyclic extension and truncation processing;
• a sequence generating section configured to generate a CAZAC sequence associated with the determined basic sequence length;
• and
• a channel estimation section configured to estimate channel quality using the CAZAC sequence, wherein:
• the association relationship (i) provides a grouping of the plurality of transmission bandwidths to which the CAZAC sequence is allocated into a plurality of transmission bandwidth groups, each transmission bandwidth group comprising at least a first transmission bandwidth and a second transmission bandwidth, and (ii) defines a first prime number that is nearest to and less than the first transmission bandwidth and a second prime number that is nearest to and less than the second transmission bandwidth, the first prime number and the second prime number being different from each other, and
• when the acquired transmission bandwidth information indicates the first transmission bandwidth, the sequence length determining section is configured to determine the sequence length having the second prime number, as the basic sequence length of the CAZAC sequence.

A channel estimation method comprising:

• determining a basic sequence length of a constant amplitude and zero-autocorrelation code (CAZAC) sequence associated with a transmission bandwidth indicated by acquired transmission bandwidth information, according to an association relationship between the basic sequence length of the CAZAC sequence and a plurality of transmission bandwidths to which the CAZAC sequence is allocated;
• a cyclic extension and truncation processing;
• generating a CAZAC sequence associated with the determined basic sequence length;
• and
• estimating channel quality using the CAZAC sequence, wherein:
• the association relationship (i) provides a grouping of the plurality of transmission bandwidths to which the CAZAC sequence is allocated into a plurality of transmission bandwidth groups, each transmission bandwidth group comprising at least a first transmission bandwidth and a second transmission bandwidth, and (ii) defines a first prime number that is nearest to and less than the first transmission bandwidth and a second prime number that is nearest to and less than the second transmission bandwidth, the first prime number and the second prime number being different from each other, and
• when the acquired transmission bandwidth information indicates the first transmission bandwidth, the sequence length determining section is configured to determine the sequence length having the second prime number, as the basic sequence length of the CAZAC sequence.