A method and an apparatus for transmitting broadcast signals thereof are disclosed. The apparatus for transmitting broadcast signals comprises an encoder for encoding service data, a mapper for mapping the encoded service data into a plurality of OFDM (Orthogonal Frequency Division Multiplex) symbols to build at least one signal frame, a frequency interleaver for frequency interleaving data in the at least one signal frame by using a different interleaving-seed which is used for every OFDM symbol pair comprised of two sequential OFDM symbols, a modulator for modulating the frequency interleaved data by an OFDM scheme and a transmitter for transmitting the broadcast signals having the modulated data.

A constant amplitude Radio Frequency (RF) signal is created by ordering complex information bearing symbols in the frequency domain along with their complex conjugates, and performing an inverse Fourier transform. This produces an analytic real-only transformed baseband signal. The real-only baseband signal is used to linearly vary the phase angle of a carrier wave while its amplitude remains constant. After reception, multi-path distortion is canceled. A time series of recovered phase angle is un-transformed with a FFT (fast Fourier transform) to produce I (in-phase) and Q (quadrature) samples. Demodulation occurs in a receiver by recovering carrier's phase angle vs. time. Forward error correction may be applied to data if desired. This may be called PM-OFDM (Phase Modulated-orthogonal frequency division multiplexing). This modulation method produces a relatively high amplitude Continuous Wave (CW) component to assist demodulation, and subcarriers near the CW can be zeroed-out to improve the CW recovery and tracking of frequency error and phase noise. The PM-OFDM signal can also be linearly precoded, creating PM-LP-OFDM. PM-LP-OFDM has a characteristic of a lower phase angle crest factor, enabling a lower peak phase rotation. Outer frequency subcarriers can be nulled to reduce occupied bandwidth, or to allow simultaneous reception of multi-user transmissions by a receiver. This can be called PM-LP-OFMDA (phase modulated-linear precoded-orthogonal frequency division multiple access).

A wireless transmission system includes: a communication unit for transmission; and a communication unit for reception. The communication units for transmission and reception are housed in a housing of the same electronic apparatus, or the communication unit for transmission is housed in a housing of first electronic apparatus and the communication unit for reception is housed in a housing of second electronic apparatus and a wireless signal transmission path enabling wireless information transmission between the communication units is formed between the communication units when the first and the second electronic apparatus are disposed at given positions to be integrated with each other. The communication unit for transmission includes a first carrier signal generating unit and a first frequency converter, and the communication unit for reception includes a second carrier signal generating unit, and a second frequency converter.

According to some embodiments, an apparatus for generating multiple variable frequency and phase locked clock signals comprises complex tuners, digital up-samplers, image isolation filters, quadrature modulators, a combiner, a DAC, a local oscillator, and an analog filter. The complex tuners tune multiple digital baseband signals. The up-samplers interpolate the complex tuned digital signals such that one of the up-sampled images of each of the complex tuned digital signals corresponds to a desired frequency. The image isolation filters isolate images corresponding to the desired frequencies. The quadrature modulators convert the isolated images of the complex tuned digital signals into real digital signals. The combiner combines the real digital signals into a combined real digital signal. The DAC, driven by the local oscillator, converts the combined real digital signal into an analog clock signal. The analog filter then filters the analog clock signal to select images located at the desired frequencies.

Disclosed are a real number M-ary signal encoding method, where M is a real number having N time dimensions and L frequency dimensions, and an encoding apparatus using the encoding method. The real number M-ary encoding apparatus according to the present invention comprises a coding unit which codes every K (K is an integer) binary bit units of binary data DATA to generate a first input code and a second input code, a first signal generator which receives the first input code and generates N.sub.1 number of M.sub.1-ary signals, a second signal generator which receives the second input code and generates N.sub.2 number of M.sub.2-ary signals, and a first time division multiplexing module which temporally multiplexes the N.sub.1 number of M.sub.1-ary signals and the N.sub.2 number of M.sub.2-ary signals to generate a real number M-ary signal which utilizes a voltage ratio a (a=A.sub.2/A.sub.1) used for M.sub.1-ary and M.sub.2-ary signals to minimize a transmission error rate.

According to some embodiments, an apparatus for generating multiple variable frequency and phase locked clock signals comprises complex tuners, digital up-samplers, image isolation filters, quadrature modulators, a combiner, a DAC, a local oscillator, and an analog filter. The complex tuners tune multiple digital baseband signals. The up-samplers interpolate the complex tuned digital signals such that one of the up-sampled images of each of the complex tuned digital signals corresponds to a desired frequency. The image isolation filters isolate images corresponding to the desired frequencies. The quadrature modulators convert the isolated images of the complex tuned digital signals into real digital signals. The combiner combines the real digital signals into a combined real digital signal. The DAC, driven by the local oscillator, converts the combined real digital signal into an analog clock signal. The analog filter then filters the analog clock signal to select images located at the desired frequencies.

Physical-layer information is conveyed within a packetized communication network via a timing-modulated side channel to yield low-latency physical interface control without consuming host-layer signaling bandwidth. Multi-modal transceivers at opposite ends of a signaling link optionally communicate to confirm mutual support and signaling headroom for timing-modulated information exchange before transitioning from an in-band feedback mode to a side-channel feedback mode.

A wireless transmission system includes: a communication unit for transmission; and a communication unit for reception. The communication units for transmission and reception are housed in a housing of the same electronic apparatus, or the communication unit for transmission is housed in a housing of first electronic apparatus and the communication unit for reception is housed in a housing of second electronic apparatus and a wireless signal transmission path enabling wireless information transmission between the communication units is formed between the communication units when the first and the second electronic apparatus are disposed at given positions to be integrated with each other. The communication unit for transmission includes a first carrier signal generating unit and a first frequency converter, and the communication unit for reception includes a second carrier signal generating unit, and a second frequency converter.

A transceiver group includes a plurality of transceivers; wherein the transceiver group performs transmission and receiving through a wire, and each of the transceivers includes a transmitter and a receiver, and the transmitter includes: a carrier generator arranged to generate a plurality of carriers having different frequencies for a plurality of data streams to be transmitted; a modulator, coupled to the data streams to be transmitted and the carrier generator, to generate a plurality of modulated data streams carried on the plurality of carriers; and a summer arranged to merge the plurality of modulated data streams to an output signal to the wire; and the receiver includes: a carrier generator arranged to generate a plurality of carriers having different frequencies for an input signal received from the wire; and a demodulator, coupled to the input signal and the carrier generator, to generate a plurality of demodulated data streams.

A system and method comprise combining, at a first combiner, a first amplitude-time modulated (ATM) signal and a first phase modulated signal to produce a complex wave modulation signal and combining, at a second combiner having an input coupled to an output of the first combiner, the complex wave modulation signal and an additional signal to produce a second complex wave modulation signal, the additional signal selected from a group consisting of a second ATM signal and a second phase modulated signal.