Obviousness

To perform a thorough obviousness analysis under 35 U.S.C. § 103, it is necessary to identify specific prior art references (e.g., patents, publications, or products) that could be combined to render the claims of US Patent 7548592 obvious.

The "Prior Art" section provided for this patent analysis only lists general keywords ("matrix", "signal", "transmitter", "transmit", "receive") rather than specific prior art documents. While the patent text discusses background techniques like Minimum Mean Squared Error (MMSE), Transmit Zero Forcing, and Filter Banks, and generally mentions prior uses of antenna arrays, it does not provide explicit citations to specific prior art patents or publications that could be used as a basis for a detailed obviousness combination analysis.

Without specific prior art references, it is not possible to:

1. Identify a primary reference: A piece of prior art that discloses most elements of a claimed invention.
2. Identify secondary references: Other pieces of prior art that disclose the remaining elements.
3. Articulate a motivation to combine: Explain why a person having ordinary skill in the art would have been motivated to combine the teachings of the primary and secondary references to arrive at the claimed invention, with a reasonable expectation of success.

Therefore, I cannot provide a detailed analysis of combinations of prior art references that would render the claims of US Patent 7548592 obvious or explain the motivation for such combinations, as the necessary specific prior art references are not available in the provided information.