초록 ▼

A wireless multicarrier transmission method wherein subcarriers of the transmission are adaptively modulated. The fading condition of each subcarrier is detected to generate fading channel profile information. Adaptive loading tables are calculated for lower, standard, and higher modulation schemes.

A wireless multicarrier transmission method wherein subcarriers of the transmission are adaptively modulated. The fading condition of each subcarrier is detected to generate fading channel profile information. Adaptive loading tables are calculated for lower, standard, and higher modulation schemes. One of the adaptive loading tables is selected and those subcarriers having low fading channel profile information are modulated with the lower modulation scheme, subcarriers having medium fading channel profile information are modulated with the standard modulation scheme, and subcarriers having high fading channel profile information are modulated with the higher modulation scheme.

대표청구항 ▼

The invention claimed is: 1. A wireless multicarrier transmission method, wherein a multicarrier transmission uses n modulated frequency subcarriers (n is an integer number), a fading condition of each subcarrier is detected to generate fading channel profile information; the modulation of each sub

The invention claimed is: 1. A wireless multicarrier transmission method, wherein a multicarrier transmission uses n modulated frequency subcarriers (n is an integer number), a fading condition of each subcarrier is detected to generate fading channel profile information; the modulation of each subcarrier is determined by the following steps: precalculating a plurality of combinations x, y, and z defining x subcarriers for modulation with a lower modulation scheme, y subcarriers for modulation with a standard modulation scheme, and z subcarriers for modulation with a higher modulation scheme (x, y, and z are integer numbers) such that a resulting number of coded bits of a multicarrier symbol is constant; wherein the sum of x, y, and z is n; selecting one of the combinations for said multicarrier transmission in order to fix the integer numbers x, y, and z during said multicarrier transmission; and modulating the x subcarriers having low fading channel profile information with the lower modulation scheme, modulating the y subcarriers having medium fading channel profile information with the standard modulation scheme, and modulating the z subcarriers having high fading channel profile information with the higher modulation scheme. 2. The method according to claim 1, wherein a transmission power of the subcarriers is adapted such that a total transmission power for all n subcarriers is unchanged. 3. The method according to claim 2, wherein the transmission power of subcarriers modulated with the higher modulation scheme is enhanced to compensate for subcarriers which are not modulated. 4. The method according to claim 1, wherein adaptive loading information reflecting an adaptation of the modulation scheme of the subcarriers is exchanged between a transmitter and a receiver of the multicarrier transmission. 5. The method according to claim 4, wherein the receiver calculates an adaptive loading based on received signals, sends the adaptive loading information in a signaling field to the transmitter; and uses the calculated adaptive loading in a data field of a transmitter data train. 6. The method according to claim 1, wherein a plurality of subcarriers is bundled into groups and the same modulation scheme is applied to all subcarriers belonging to the same group. 7. The method according to claim 6, wherein a plurality of adjacent subcarriers is bundled into one group. 8. A computer-readable medium for storing therein a computer software program running on a wireless transmitting device for executing a wireless multicarrier transmission that uses n modulated frequency subcarriers (n is an integer number); a fading condition of each subcarrier is detected to generate fading channel profile information; the program determines the modulation of each subcarrier by performing the following steps: precalculating a plurality of combinations x, y, and z defining x subcarriers for modulation with a lower modulation scheme, y subcarriers for modulation with a standard modulation scheme, and z subcarriers for modulation with a higher modulation scheme (x, y, and z are integer numbers) such that a resulting number of coded bits of a multicarrier symbol is constant; wherein the sum of x, y, and z is n; selecting one of the combinations for said multicarrier transmission in order to fix the integer numbers x, y, and z during said multicarrier transmission; and modulating the x subcarriers having low fading channel profile information with the lower modulation scheme, modulating the y subcarriers having medium fading channel profile information with the standard modulation scheme, and modulating the z subcarriers having high fading channel profile information with the higher modulation scheme. 9. A wireless multicarrier transmission device for a multicarrier transmission uses n modulated frequency subcarriers (n is an integer number), comprising: a fading channel profile unit for detecting a fading condition of each subcarrier; a unit for precalculating a plurality of combinations x, y, and z defining x subcarriers for modulation with a lower modulation scheme, y subcarriers for modulation with a standard modulation scheme, and z subcarriers for modulation with a higher modulation scheme (x, y, and z are integer numbers) such that a resulting number of coded bits of a multicarrier symbol is constant; wherein the sum of x, y, and z is n; selecting means for selecting one of the combinations for said multicarrier transmission in order to fix the integer numbers x, y, and z during the multicarrier transmission; and an adaptive bits-to-symbol mapping unit for modulating the x subcarriers having low fading channel profile information with the lower modulation scheme, modulating the y subcarriers having medium fading channel profile information with the standard modulation scheme, and modulating the z subcarriers having high fading channel profile information with the higher modulation scheme. 10. The device according to claim 9, wherein the unit for precalculating bundles respectively a plurality of subcarriers into groups and applies the same modulation scheme to all subcarriers belonging to the same group. 11. The device according to claim 10, wherein the unit for precalculating bundles a plurality of adjacent subcarriers into one group.