Communication device for receiving and transmitting OFDM signals in a wireless communication system
A communication device for transmitting orthogonal frequency division multiplexed (OFDM) signals in a wireless communication system. The device includes a plurality of antenna elements that transmit the OFDM signals to a receiver over a plurality of transmission channels in the wireless communication system. The device also generates weight coefficients applied to each of the plurality of subcarrier signals, and controls an amplitude and/or phase of the plurality of subcarrier signals as a function of said weight coefficients.
1. A communication device for transmitting OFDM signals in a wireless communication system, the communication device comprising:
antenna means having a plurality of antenna elements for transmitting said OFDM signals propagated through a plurality of transmission channels in said wireless communication system;
means for generating complex weight coefficients which are respectively applied to OFDM subcarrier signals to be transmitted; and
means for controlling amplitude and/or phase of each of said OFDM subcarrier signals based on said complex weight coefficients for the OFDM subcarrier signals to be transmitted through said plurality of transmission channels, wherein
said weight coefficients are chosen to improve the performance of a total of combined OFDM subcarriers to be transmitted, and
the performance of the total combined OFDM subcarriers is expressed by said weight coefficients and a Hermitian matrix having elements of channel vectors, and the weight coefficients are chosen based on an Eigenvector of an Eigenvalue of said Hermitian matrix.
2. The communication device of claim 1 , wherein
the means for controlling controls an amplitude and/or phase of each of said OFDM subcarrier signals individually as a function of said weight coefficients.
3. The communication device of claim 1 , wherein
said Eigenvalue of said Hermitian matrix is a maximum Eigenvalue of said Hermitian matrix.
4. A communication device for transmitting OFDM signals in a wireless communication system the communication device comprising:
an antenna having a plurality of antenna elements that transmit said OFDM signals propagated through a plurality of transmission channels in said wireless communication system; and
circuitry configured to
generate complex weight coefficients which are respectively applied to OFDM subcarrier signals to be transmitted; and
control amplitude and/or phase of each of said OFDM subcarrier signals based on said complex weight coefficients for the OFDM subcarrier to be transmitted through said plurality of transmission channels, wherein
said weight coefficients are chosen to improve the performance of a total of combined OFDM subcarriers to be transmitted, and
the performance of the total combined OFDM subcarriers is expressed by said weight coefficients and a Hermitian matrix having elements of channel vectors, and the weight coefficients are chosen based on an Eigenvector of an Eigenvalue of said Hermitian matrix.
5. The communication device of claim 4 , wherein
the controller controls an amplitude and/or phase of each of said OFDM subcarrier signals individually as a function of said weight coefficients.
6. The communication device of claim 4 , wherein
said Eigenvalue of said Hermitian matrix is a maximum Eigenvalue of said Hermitian matrix.
7. A communication method for transmitting OFDM signals in a wireless communication system, the communication method comprising the steps of:
transmitting said OFDM signals propagated through a plurality of transmission channels in said wireless communication system;
generating complex weight coefficients which are respectively applied to OFDM subcarrier signals to be transmitted; and
controlling amplitude and/or phase of each of said OFDM subcarrier signals based on said complex weight coefficients for the OFDM subcarrier signals to be transmitted through said plurality of transmission channels, wherein
said weight coefficients are chosen to improve the performance of a total of combined OFDM subcarriers to be transmitted, and
the performance of the total combined OFDM subcarriers is expressed by said weight coefficients and a Hermitian matrix having elements of channel vectors, and the weight coefficients are chosen based on an Eigenvector of an Eigenvalue of said Hermitian matrix.
8. The communication method of claim 7 , wherein
the controlling includes controlling an amplitude and/or phase of each of said OFDM subcarrier signals individually as a function of said weight coefficients.
9. The communication method of claim 7 , wherein
said Eigenvalue of said Hermitian matrix is a maximum Eigenvalue of said Hermitian matrix.