A peak-to-average ratio reduction method, including dividing subcarriers of an orthogonal frequency division multiplexing (OFDM) symbol that carries to-be-transmitted data to obtain multiple blocks, determining multiple phase factors corresponding to the multiple blocks, where the multiple phase factors reduce a peak-to-average ratio of the OFDM symbol, transmitting the multiple phase factors using a particular subcarrier of the OFDM symbol, multiplying data transmitted on each block in the multiple blocks by a corresponding phase factor, and transmitting data obtained by means of multiplication. Phase factor information of each block is transmitted using the particular subcarrier such that application of a partial transmit sequence (PTS) method in a WI-FI system becomes possible, thereby effectively reducing a peak-to-average power ratio (PAPR) of data.

Aspects of the present invention include apparatus and methods for transmitting and receiving signals in communication systems. A multicarrier generator generates a multicarrier signal. An optical demultiplexer separates the multicarrier signal into separate multicarrier signals. At least one QPSK modulator modulates signals from the separate multicarrier signals. An optical multiplexer combines the QPSK modulated signals into a multiplexed signal. The multiplexed signal is then transmitted.

The present invention provides an apparatus of transmitting broadcast signals, the apparatus including, an encoder for encoding service data, a frame builder for building at least one signal frame by mapping the encoded service data, a modulator for modulating data in the built at least one signal frame by an Orthogonal Frequency Division Multiplexing, OFDM, scheme and a transmitter for transmitting the broadcast signals having the modulated data.

Increasing an analog to digital converter (ADC) dynamic range for a communications device. In the communications device, a reference threshold is established for a peak to average power ratio (PAPR) improvement factor for RF signals received by the communications device. A digital to analog converter (DAC) adjustment factor is established for a DAC to account for inaccuracies of a pre-cancellation DAC and fine tuning of an analog gain of received RF signals. A peak amplitude separation element evaluates an absolute value of a portion of a particular RF signal against the reference threshold. Upon the peak amplitude separation element determining that the portion is smaller than the reference threshold, the element assigns a zero value to a DAC signal current sample; otherwise, the element assigns a quantized value of the sample to the DAC signal current sample, used in adjusting a post-cancellation signal sample.

Methods, systems, and devices for wireless communications are described. In some systems, a transmitting device may identify one or more blocks of data for transmission to a receiving device. The transmitting device may map subsets of bits of the one or more blocks of data to a constellation of symbol points of a modulation order to obtain a set of symbols and may then transmit a signal including the set of symbols to a receiving device. In some systems, a receiving device may receive, from the transmitting device, the signal including the set of symbols associated with blocks of data. The receiving device may de-map the set of symbols according to a constellation of symbol points of a modulation order to obtain a plurality of sets of de-mapped data bits and decode a plurality of sets of de-mapped data bits to obtain the blocks of data.

A heart generated signal is provided by a heart sensor of a mobile device to an analog to digital (A/D) converter for A/D converting the sensor provided signal. The A/D converted heart signal is processed to provide heart rate. The heart rate is recorded or stored in the mobile device or is transmitted in a wireless communication system. The mobile device receives sensor provided Electro Cardiogram (ECG) signal. The ECG signal is stored or is provided to an interface unit. The mobile device has transceivers for receiving and transmitting Orthogonal Frequency Division Multiplexed (OFDM) signals and for modulating and transmitting spread spectrum baseband signals. The spread spectrum baseband signals have cross-correlated in-phase and quadrature-phase filtered baseband signals.

Methods and apparatus for processing multichannel signals in a multichannel receiver are described. In one implementation, a plurality of demodulator circuits may provide a plurality of outputs to a processing module, with the processing module then simultaneously estimating noise characteristics based on the plurality of outputs and generating a common noise estimate based on the plurality of outputs. This common noise estimate may then be provided back the demodulators and used to adjust the demodulation of signals in the plurality of demodulators to improve phase noise performance.

An FEC coder in a transmission device according to an exemplary embodiment of the present disclosure performs BCH coding and LDPC coding based on whether a code length of the LDPC coding is a 16k mode or a 64k mode. A mapper performs mapping in an I-Q coordinate to perform conversion into an FEC block, and outputs pieces of mapping data (cells). The mapper defines different non-uniform mapping patterns with respect to different code lengths even an identical coding rate is used by the FEC coder. This configuration improves a shaping gain for different error correction code lengths in a transmission technology in which modulation of the non-uniform mapping pattern is used.

This application relates to a method for acquiring a CQI, a user equipment, an eNB and a system. The method includes: calculating CQIs of at least two subbands, where there is an overlapped resource block between the subbands; and transmitting the subband CQIs to an eNB. In the method for acquiring a channel quality indicator, the user equipment, the evolved node B and the system of the present application, there is an overlapped resource block between adjacent subbands, and meanwhile the channel quality of the resource block of the subband is obtained by using different subbands, thus the feedback accuracy of the channel quality of the resource block of each subband, especially the channel quality of the resource block in the subband overlapping area, thereby improving the granularity of frequency-selective scheduling, and improving the frequency-selective scheduling and the link adaptation, and therefore, the system throughput is increased.

A front-end circuit is used to test an RF signal from an RF device. The RF signal is generated by modulating a carrier signal having a carrier frequency with a wideband baseband signal. A variable frequency oscillator generates a local signal having a variable local frequency. The first frequency mixer frequency mixes a local signal and an RF signal to generate an IF signal having a frequency. A band-pass type first filter filters the IF signal. The local frequency can be selected from a plurality of frequencies having a frequency interval equal to or narrower than a bandwidth of the first filter.