Method for dynamically setting virtual subcarriers, receiving method, apparatus and system

A method for receiving dynamic virtual subcarriers, applied to a multicarrier transmission system, the method comprising:

• receiving, by a receiver of the multicarrier transmission system, a virtual subcarrier adjustment indication sent by a transmitter of the multicarrier transmission system, wherein the virtual subcarrier adjustment indication comprises a number of left edge virtual subcarriers, a number of right edge virtual subcarriers and a virtual subcarrier adjustment time of the multicarrier transmission system;
• wherein a sum of the number of the left edge virtual subcarriers and the number of the right edge virtual subcarriers is not less than an aliasing guard band of a baseband signal of the multicarrier transmission system, and is not greater than a dimension of discrete Fourier transform of the baseband signal;
• and the aliasing guard band of the baseband signal is a minimum number of the virtual subcarriers required when spectrum aliasing of the baseband signal does not exceed a first preset threshold;
• determining, by the receiver, starting from a first subcarrier at a left edge of a working spectrum of the receiver, within the working spectrum, contiguous subcarriers a number of which equals the number of the left edge virtual subcarriers as a first group of virtual subcarriers, and selecting, by the receiver, starting from a last subcarrier at a right edge of the working spectrum, within the working spectrum, contiguous subcarriers a number of which equals the number of the right edge virtual subcarriers as a second group of virtual subcarriers;
• and
• setting, by the receiver, at the virtual subcarrier adjustment time, virtual subcarriers of the multicarrier transmission system according to the numbers of the first group of virtual subcarriers and the number of the second group of virtual subcarriers.

An apparatus for dynamically setting virtual subcarriers, applied to a multicarrier transmission system, the apparatus comprising:

• a spectrum acquiring module, configured to acquire dynamic spectrum information of a geographic location where the apparatus for dynamically setting the virtual subcarriers is located;
• a virtual subcarrier determining module, configured to determine a number of left edge virtual subcarriers and a number of right edge virtual subcarriers of the multicarrier transmission system at left and right edges of a working spectrum of the apparatus, respectively, for dynamically setting the virtual subcarriers according to the dynamic spectrum information, to make a sum of the number of the left edge virtual subcarriers and the number of the right edge virtual subcarriers be not less than an aliasing guard band of a baseband signal of the multicarrier transmission system, and be not greater than a dimension of discrete Fourier transform of the baseband signal;
• wherein the aliasing guard band of the baseband signal is a minimum number of the virtual subcarriers required when spectrum aliasing of the baseband signal does not exceed a first preset threshold;
• a virtual subcarrier setting module, configured to set, by the transmitter, the virtual subcarriers of the multicarrier transmission system according to the number of the left edge virtual subcarriers and the number of the right edge virtual subcarriers determined;
• and
• an adjustment indication module, configured to send, after determining the number of the left edge virtual subcarriers and the number of the right edge virtual subcarriers of the multicarrier transmission system, a virtual subcarrier adjustment indication to a receiver, wherein the virtual subcarrier adjustment indication comprises the number of the left edge virtual subcarriers, the number of the right edge virtual subcarriers and a virtual subcarrier adjustment time of the multicarrier transmission system, to enable the receiver to set the virtual subcarriers of the multicarrier transmission system according to the left edge virtual subcarriers and the right edge virtual subcarriers determined, when the virtual subcarrier adjustment time arrives.

An apparatus for receiving dynamic virtual subcarriers, applied to a multicarrier transmission system, the apparatus comprising:

• an indication receiving module, configured to receive a virtual subcarrier adjustment indication sent by a transmitter, wherein the virtual subcarrier adjustment indication comprises a number of left edge virtual subcarriers, a number of right edge virtual subcarriers and a virtual subcarrier adjustment time of the multicarrier transmission system;
• wherein a sum of the number of the left edge virtual subcarriers and the number of the right edge virtual subcarriers is not less than an aliasing guard band of a baseband signal of the multicarrier transmission system, and is not greater than a dimension of discrete Fourier transform of the baseband signal;
• and the aliasing guard band of the baseband signal is a minimum number of the virtual subcarriers required when spectrum aliasing of the baseband signal does not exceed a first preset threshold;
• a determining module, configured to determine, starting from a first subcarrier at a left edge of a working spectrum of the apparatus for receiving the dynamic virtual subcarriers, within the working spectrum, contiguous subcarriers a number of which equals the number of the left edge virtual subcarriers as a first group of virtual subcarriers, and select, by the receiver, starting from a last subcarrier at a right edge of the working spectrum, within the working spectrum, contiguous subcarriers a number of which equals the number of the right edge virtual subcarriers as a second group of virtual subcarriers;
• and
• a setting module, configured to set virtual subcarriers of the multicarrier transmission system according to the number of the first group of virtual subcarriers and the number of the second group of virtual subcarriers at the virtual subcarrier adjustment time.