A communication apparatus includes a receiver, a combiner, and a transformer. The receiver receives signals mapped on plural frequency bands. A size of at least one of the frequency bands is a multiple of a product of two or more powers of prime numbers, which are integer numbers greater than 1 and are different from each other. An exponent for at least one of the prime numbers is an integer greater than 1. The combiner combines the received signals into a combined signal. The transformer transforms the combined signal in a frequency domain into a symbol sequence in a time domain with an inverse discrete Fourier transform (IDFT) having a size that is a product of powers of plural values. The values are integer numbers greater than 1 and are different from each other. An exponent for at least one of the values is an integer greater than 1.

A method for extracting a plurality of data streams from a time-frequency division multiplexed (TFDM) signal includes determining a plurality of sub-channels of the TFDM signal, where each of the plurality of sub-channels has a respective one of a plurality of frequency ranges. The method also includes down-converting, based on the plurality of frequency ranges, the TFDM signal into a plurality of down-converted signals, where each down-converted signal corresponds to a respective one of the plurality of sub-channels. The method also includes extracting the plurality of data streams from a respective one of the plurality of down-converted signals.

A communication apparatus includes a receiver, a combiner, and a transformer. The receiver receives signals mapped on plural frequency bands. A size of at least one of the frequency bands is a multiple of a product of two or more powers of prime numbers, which are integer numbers greater than 1 and are different from each other. An exponent for at least one of the prime numbers is an integer greater than 1. The combiner combines the received signals into a combined signal. The transformer transforms the combined signal in a frequency domain into a symbol sequence in a time domain with an inverse discrete Fourier transform (IDFT) having a size that is a product of powers of plural values. The values are integer numbers greater than 1 and are different from each other. An exponent for at least one of the values is an integer greater than 1.

Certain aspects of the present disclosure propose techniques for independently signaling features supported by a user equipment (UE) in different duplexing modes. The UE may be capable of communicating in frequency division duplexing (FDD) and time division duplexing (TDD) modes. The UE may obtain a FDD-specific feature group indicators (FGIs) set and a TDD-specific FGIs set, and signal at least one of the FDD-specific FGIs set or TDD-specific FGIs set. In addition, the UE may take one or more actions to reduce the likelihood of transitioning to a mode of operation that is different from its current mode of operation.

An OFDM communication transceiver, which is configured to test its connection with an antenna circuit unit, has a receiver chain and an emitting chain. The receiver chain includes a time-to-frequency transform unit and the emitting chain includes a frequency-to-time transform unit. The transceiver further includes means for disconnecting the receiver chain to the antenna circuit unit, means for providing a stimulus as input to the emitting chain, means for reintroducing the signal at the output of the emitting chain as an input of the receiving chain, means for determining a circuit resonance frequency, Fr, and a quality factor, Q, of a transfer function computed from the output of the time-to-frequency transform unit, and means for deciding about the connection of said antenna circuit unit according to the resonance frequency and the quality factor.

A communication apparatus includes a receiver, a combiner, and a transformer. The receiver receives signals mapped on plural frequency bands. A size of at least one of the frequency bands is a multiple of a product of two or more powers of prime numbers, which are integer numbers greater than 1 and are different from each other. An exponent for at least one of the prime numbers is an integer greater than 1. The combiner combines the received signals into a combined signal. The transformer transforms the combined signal in a frequency domain into a symbol sequence in a time domain with an inverse discrete Fourier transform (IDFT) having a size that is a product of powers of plural values. The values are integer numbers greater than 1 and are different from each other. An exponent for at least one of the values is an integer greater than 1.