Abstract: Two dimensional interpolation techniques are used to compensate for time-varying channel gain H in an OFDM system. The channel gain can be reasonably estimated at various times and at various frequencies due, for example, to the use of pilot tones. These channel estimates are used to estimate the channel gain at other times and/or frequencies by two-dimensional interpolation, interpolating first with respect to time (e.g., with respect to a symbol index s) and then with respect to frequency (e.g., with respect to a sub-carrier index c).

Abstract: Methods and systems for amplifying signals are provided. Embodiments include a three-to-one multiplexer, a multiband RF variable gain amplifier (VGA), a multiband power amplifier driver (PAD), and a one-to three multiplexer. The three-to-one multiplexer receives three input signals from an RF frequency source and outputs an output signal corresponding one input signal. The multiband RF VGA receives the output signal of the three-to-one multiplexer, provides a first level of amplification to the signal received from the three-to-one multiplexer, and outputs an amplified version of the signal. The multiband PAD receives the signal output by the multiband RF variable gain amplifier and provides a second level of amplification to the signal and outputs an amplified version of the signal. The one-to-three multiplexer receives a signal output by the multiband PAD produces three output signals that correspond to each of the three input signals.

Abstract: The present invention provides a system and method for operating hybrid concurrent and switched dual-band low noise amplifiers. Embodiments use a concurrent design at the input block of a hybrid LNA to advantageously achieve better impedance matching while using a switch capacitor design at the output block to advantageously achieve a better gain than typical concurrent multiband LNAs. Embodiments might be integrated into wireless devices configured to simultaneously receive on multiple frequency bands while providing gains of 30 dB or more by combining the advantages of concurrent multiband LNAs with the advantages of switched multiband LNAs. In addition to the higher gains provided by embodiments of the hybrid LNA described herein, hybrid multiband LNAs according to embodiments of the present invention provide a smaller device footprint and power requirements than would be required for a receiver including multiple single-band LNAs for amplifying signals for each frequency band individually.