This disclosure describes methods, apparatus, and systems related to early bit indication system. A device may identify a high efficiency frame in accordance with a high efficiency communication standard, received from a first device, the high efficiency frame including at least in part a legacy signal field and a high efficiency signal field. The device may determine a length field included in the legacy signal field. The device may determine one or more bits included in the length field. The device may determine a repeated high efficiency signal field based at least in part on the one or more bits.

A system and method for estimating clock drift in underwater instruments is provided. The method can include transmitting a signal from a source to a plurality of underwater receivers or a single receiver. Upon recovery of the underwater receivers, an initial sampling frequency value can be used to generate received data waveforms from data stored on each underwater device. The generated received waveforms can be used to generate a channel estimate for each receiver, and the channel estimates can be used to provide an estimate of the source motion during the transmission. The estimated source motion can then be used to estimate the clock drift.

Certain aspects of the present disclosure relate to methods and apparatus relating to a long uplink burst channel design. In certain aspects, the method includes determining, based on a hopping pattern, a first set of frequency resources available for transmitting uplink control information (UCI) within a first portion of a transmission time interval (TTI) and a second set of frequency resources available for transmitting UCI within a second portion of the TTI. The method also includes transmitting the UCI using the determined first set of frequency resources and the second set of frequency resources.

A method is provided for transmitting broadcast signals. The method includes encoding, by an encoder, service data, encoding, by a signaling encoder, signaling data based on modes of the signaling data, wherein the signaling data is categorized into each mode representing a Low Density Parity Check (LDPC) code rate and a modulation order for the signaling data, building, by a frame builder, at least one signal frame including the encoded service data in at least one data symbol and the encoded signaling data in at least one signaling symbol, modulating, by a modulator, data in the at least one signal frame by an Orthogonal Frequency Division Multiplex (OFDM) scheme, and transmitting, by a transmitter, the broadcast signals carrying the modulated data in the at least one signal frame. One of the modes for the signaling data represents a 6/15 LDPC code rate and a Quadrature Phase Shift Keying (QPSK) modulation.

A method for allocating bandwidth to communication according to a first communication protocol, the method comprising identifying bandwidth that is allocated to a communication channel for communication according to a second communication protocol and which forms a guard band of the communication channel and allocating the identified bandwidth to communication according to the first communication protocol, said allocation being performed non-uniformly across the identified bandwidth such that an allocation of a first portion of the identified bandwidth, which is located closer to a communication according to the second communication protocol than a second portion of the identified bandwidth, is constrained to a greater extent than an allocation of the second portion of the identified bandwidth.

The present disclosure relates to a communication method and system for converging a 5G communication system for supporting higher data rates beyond a 4G system with an IoT technology. The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. The present disclosure can reduces a peak-to-average power ration (PAPR) by performing time domain cyclic filtering. Further, a data rate or coverage can be improved by selectively transmitting transmission waveforms through cyclic prefix (CP)-orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform-spread-OFDM (DFT-s-OFDM).

There is provided an ultra-light decoder for high speed digital communications based on block codes such as turbo product codes (TPCs). The new decoder can perform soft decision decoding without an algebraic hard decision decoder, which is the core of conventional soft decision decoders. The elimination of algebraic decoder significantly reduces the number of computations required per codeword, consequently, it reduces the decoding delay and processing power. However, reducing the decoding delay would immediately enable increasing the transmission speed, and minimize the need for large buffers at the receiver. Moreover, reducing the complexity and delay would enable using codes with high code rates to increase the system capacity, or use powerful codes with low code rates to reduce the transmission power. Such benefits can be achieved for about 1 dB loss in coding gain. There is also provided a receiver comprising the ultra-light decoder, as well as a decoding process.

A candidate arbitrary-phase spread spectrum modulation technique that offers similar performance to spread continuous phase modulation (CPM) waveforms and additional capabilities for programming a chosen frequency domain spectra into the resulting spread spectrum signal. The proposed chaotic-FSK waveform is derived from high-order sequence-based spread spectrum signals, with multi-bit resolution chaos-based sequences defining incremental phase words, enabling real-time efficient generation of practically non-repeating waveforms. A result of the C-FSK formulation is a parameterized hybrid modulation capable of acting like a traditional sequence-based spread spectrum signal or a traditional frequency shift keying signal depending on chosen parameters. As such, adaptation in this modulation may be easily implemented as a time-varying evolution, increasing the security of the waveform while retaining many efficiently implementable receiver design characteristics of traditional PSK modulations.

An implantable wireless device for transmitting data includes an external control device and an internal processing device. The external control device receives digital data and an alternating current carrier signal and uses the alternating current carrier signal to modulate the digital data into a phase shift keying modulation signal. The digital data have a plurality of time points that binary data change. The internal processing device includes a phase-lock loop (PLL)-based phase shift keying demodulator. The PLL-based phase shift keying demodulator obtains a ripple voltage signal according to the phase shift keying modulation signal. The ripple voltage signal decreases from a fixed voltage value at each of the plurality of time points and then increases to the fixed voltage value. The PLL-based phase shift keying demodulator demodulates the ripple voltage signal into the digital data.

Various embodiments are generally directed to an apparatus, method and other techniques to determine a bandwidth in a frequency band to communicate information to stations, determine an Orthogonal Frequency-Division Multiple Access (OFDMA) tone allocation scheme based on the bandwidth, the OFDMA tone allocation scheme to include one or more resource units each comprising a plurality of tones and each having a fixed location in the bandwidth, and communicate information to the stations based on the OFDMA tone allocation scheme.