Radio apparatus
A plurality of antennas respectively conveys burst signals that use a plurality of subcarriers and contain control information for communications. When a plurality of subcarriers are used, a cyclic time shifting in a cycle in time domain is executed, per antenna, with a time-shift amount corresponding to each of the plurality of antennas. A control unit generates the burst signals informed from the plurality of antennas by complying with this rule. The control unit generates the burst signals by varying time shift amounts corresponding respectively to the plurality of antennas.
1. A transmitting apparatus comprising:
a generation unit configured to generate a packet signal including a plurality of CDD (Cyclic Delay Diversity)-applied streams; and
a radio unit configured to send the packet signal from a plurality of antennas, wherein
the generation unit includes in the packet signal, information permitting a receiving apparatus to perform a smoothing process of channel coefficients across sub-carries when an amount of shift for CDD for the packet signal to be sent from the plurality of antennas becomes smaller than a threshold value defined for time, otherwise prohibiting the receiving apparatus to perform the smoothing process,
wherein the generation unit generates a packet signal in which a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal field L-SIG), a high throughput signal field (HT-SIG), a high throughput short training field (HT-STF), multiple high throughput long training fields (HT-LTF), and data are assigned in the stated order and the information is included in the high throughput short training field (HT-SIG).
2. The transmitting apparatus according to claim 1 , further comprising a transmission unit configured to transmit the packet signal generated in the generation unit from a plurality of antennas.
3. A transmitting apparatus comprising:
a generation unit configured to generate a packet signal including a plurality of streams, each stream being subject to a cyclic time shift amount,
a radio unit configured to send the packet signal from a plurality of antennas,
wherein the packet signal includes information indicative of execution of smoothing process of channel coefficients across sub-carriers at the time of receiving,
wherein said information is indicative of permission of execution when an amount of shift for Cyclic Delay Diversity (CDD) introduced by said generation unit is shorter than a predetermined time amount,
wherein said information is indicative of non-execution when the amount of shift for CDD introduced by said generation unit is longer than said predetermined time amount, and
wherein the generation unit generates a packet signal in which a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal field (L-SIG), a high throughput signal field (HT-SIG), a high throughput short training field (HT-STF), multiple high throughput long training fields (HT-LTF), and data are assigned in the stated order and the information is included in the high throughput short training field (HT-SIG).
4. The transmitting apparatus according to claim 3 , further comprising a transmission unit configured to transmit the packet signal generated in the generation unit from a plurality of antennas.
5. A receiving apparatus comprising:
a radio unit configured to receive a packet signal including a plurality of streams, each stream being subject to a cyclic time shift amount, wherein the packet signal includes information indicative of execution of smoothing process of channel coefficients across sub-carriers at the time of receiving,
a processing unit configured to determine, as a function of said information included in said packet signal, whether to carry out or not to carry out the smoothing process of channel coefficients across sub-carriers,
wherein said information is created by a transmitting apparatus that sent the packet signal, and
wherein the generation unit generates a packet signal in which a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signal field (L-SIG), a high throughput signal field (HT-SIG), a high throughput short training field (HT-STF), multiple high throughput long training fields (HT-LTF), and data are assigned in the stated order and the information is included in the high throughput short training field (HT-SIG).
6. The receiving apparatus according to claim 5 , wherein said packet signal is transmitted from a plurality of antennas.