A communication system includes a repetitive orthogonal frequency-division multiplexing (“ROFDM”)transmitter communicating with an ROFDM receiver. The ROFDM transmitter includes an ROFDM modulator, which includes a K-point Fast Fourier Transform receiving a block of time-domain data symbols and generating an initial orthogonal frequency-division multiplexing symbol. The initial orthogonal frequency-division multiplexing symbol is based on a block of frequency-domain data symbols corresponding to the block of time-domain data symbols. The initial orthogonal frequency-division multiplexing symbol includes an ending part. The ROFDM modulator includes an orthogonal frequency-division multiplexing symbol repeater generating a repetitive orthogonal frequency-division multiplexing symbol by repeatedly reproducing the initial orthogonal frequency-division multiplexing symbol. The modulator includes a cyclic prefix adder pretending a cyclic prefix to the repetitive orthogonal frequency-division multiplexing symbol to generate a baseband transmitted signal. The cyclic prefix includes the ending part of the initial orthogonal frequency-division multiplexing symbol. The ROFDM receiver includes an ROFDM demodulator.

A wide-band analog input signal is converted into a digital output signal on the basis of a band division method without the need for filter circuits. An analog processing block A.sub.j (j=2 to N, where N is an integer) down-converts an analog input signal S.sub.x using a cutoff frequency fj-1 of a channel CH.sub.j-1 and A/D-converts an analog signal S.sub.aj acquired as a result. A digital processing block B.sub.j doubles the signal strength of a first digital signal S.sub.1j acquired by A.sub.j, subtracts a third digital signal S.sub.3j-1 of the channel CH.sub.j-1 from a second digital signal S.sub.2j acquired as a result, up-converts the acquired third digital signal S.sub.3j using the cutoff frequency f.sub.j-1, and outputs the result to an adder as a channel output signal S.sub.yj of a corresponding channel CH.sub.j.

A wide-band analog input signal is converted into a digital output signal on the basis of a band division method without the need for filter circuits. An analog processing block A.sub.j (j=2 to N, where N is an integer) down-converts an analog input signal S.sub.x using a cutoff frequency fj-1 of a channel CH.sub.j-1 and A/D-converts an analog signal S.sub.aj acquired as a result. A digital processing block B.sub.j doubles the signal strength of a first digital signal S.sub.1j acquired by A.sub.j, subtracts a third digital signal S.sub.3j-1 of the channel CH.sub.j-1 from a second digital signal S.sub.2j acquired as a result, up-converts the acquired third digital signal S.sub.3j using the cutoff frequency f.sub.j-1, and outputs the result to an adder as a channel output signal S.sub.yj of a corresponding channel CH.sub.j.

An apparatus is disclosed for multiplexing radar beat signals. In an example aspect, the apparatus includes an antenna array and a wireless transceiver jointly configured to transmit a radar transmit signal and receive two or more radar receive signals. The two or more radar receive signals represent portions of the radar transmit signal that are reflected by an object. The wireless transceiver comprises a radio-frequency integrated circuit with two or more receive chains and a multiplexing circuit. Each one of the two or more receive chains is configured to generate a radar beat signal by downconverting a respective radar receive signal of the two or more radar receive signals using the radar transmit signal. The multiplexing circuit is coupled to the two or more receive chains and is configured to multiplex the two or more radar beat signals together to generate a composite radar beat signal.

An apparatus is disclosed for multiplexing radar beat signals. In an example aspect, the apparatus includes an antenna array and a wireless transceiver jointly configured to transmit a radar transmit signal and receive two or more radar receive signals. The two or more radar receive signals represent portions of the radar transmit signal that are reflected by an object. The wireless transceiver comprises a radio-frequency integrated circuit with two or more receive chains and a multiplexing circuit. Each one of the two or more receive chains is configured to generate a radar beat signal by downconverting a respective radar receive signal of the two or more radar receive signals using the radar transmit signal. The multiplexing circuit is coupled to the two or more receive chains and is configured to multiplex the two or more radar beat signals together to generate a composite radar beat signal.

Systems and methods are provided for channelizing. A first stage can provide a WOLA filter bank that can apply a single multiplier resource to perform window weighting for multiple WOLA filter banks. The first stage can remove mixer-based post FFT adjustment and provide equal functionality with a particular modification of tuning mixers at inputs of second stage FIR paths. The first stage can include a variable decimation, using a particular implementation of variable sample block size.

Systems and methods are provided for channelizing. A first stage can provide a WOLA filter bank that can apply a single multiplier resource to perform window weighting for multiple WOLA filter banks. The first stage can remove mixer-based post FFT adjustment and provide equal functionality with a particular modification of tuning mixers at inputs of second stage FIR paths. The first stage can include a variable decimation, using a particular implementation of variable sample block size.

A communication system includes a repetitive orthogonal frequency-division multiplexing (ROFDM)transmitter communicating with an ROFDM receiver. The ROFDM transmitter includes an ROFDM modulator, which includes a K-point Fast Fourier Transform receiving a block of time-domain data symbols and generating an initial orthogonal frequency-division multiplexing symbol. The initial orthogonal frequency-division multiplexing symbol is based on a block of frequency-domain data symbols corresponding to the block of time-domain data symbols. The initial orthogonal frequency-division multiplexing symbol includes an ending part. The ROFDM modulator includes an orthogonal frequency-division multiplexing symbol repeater generating a repetitive orthogonal frequency-division multiplexing symbol by repeatedly reproducing the initial orthogonal frequency-division multiplexing symbol. The modulator includes a cyclic prefix adder pretending a cyclic prefix to the repetitive orthogonal frequency-division multiplexing symbol to generate a baseband transmitted signal. The cyclic prefix includes the ending part of the initial orthogonal frequency-division multiplexing symbol. The ROFDM receiver includes an ROFDM demodulator.

A communication system includes a repetitive orthogonal frequency-division multiplexing (ROFDM)transmitter communicating with an ROFDM receiver. The ROFDM transmitter includes an ROFDM modulator, which includes a K-point Fast Fourier Transform receiving a block of time-domain data symbols and generating an initial orthogonal frequency-division multiplexing symbol. The initial orthogonal frequency-division multiplexing symbol is based on a block of frequency-domain data symbols corresponding to the block of time-domain data symbols. The initial orthogonal frequency-division multiplexing symbol includes an ending part. The ROFDM modulator includes an orthogonal frequency-division multiplexing symbol repeater generating a repetitive orthogonal frequency-division multiplexing symbol by repeatedly reproducing the initial orthogonal frequency-division multiplexing symbol. The modulator includes a cyclic prefix adder pretending a cyclic prefix to the repetitive orthogonal frequency-division multiplexing symbol to generate a baseband transmitted signal. The cyclic prefix includes the ending part of the initial orthogonal frequency-division multiplexing symbol. The ROFDM receiver includes an ROFDM demodulator.

A communication system includes a repetitive orthogonal frequency-division multiplexing (ROFDM) transmitter communicating with an ROFDM receiver. The ROFDM transmitter includes an ROFDM modulator, which includes a K-point Fast Fourier Transform receiving a block of time-domain data symbols and generating an initial orthogonal frequency-division multiplexing symbol. The initial orthogonal frequency-division multiplexing symbol is based on a block of frequency-domain data symbols corresponding to the block of time-domain data symbols. The initial orthogonal frequency-division multiplexing symbol includes an ending part. The ROFDM modulator includes an orthogonal frequency-division multiplexing symbol repeater generating a repetitive orthogonal frequency-division multiplexing symbol by repeatedly reproducing the initial orthogonal frequency-division multiplexing symbol. The modulator includes a cyclic prefix adder prepending a cyclic prefix to the repetitive orthogonal frequency-division multiplexing symbol to generate a baseband transmitted signal. The cyclic prefix includes the ending part of the initial orthogonal frequency-division multiplexing symbol. The ROFDM receiver includes an ROFDM demodulator.