Methods, systems, and devices for wireless communications are described. In one example, a receiving device (e.g., a UE) may transmit, to a transmitting device (e.g., a base station), a capability indicator indicating a capability of the receiving device to perform peak reconstruction using soft metrics (e.g., expected value, covariance) on symbol decisions. The receiving device may receive, from the transmitting device and based on the capability indicator, control signaling indicating a clipping level applied to generate a signal and a subset of peaks clipped from the signal. The receiving device may receive the signal generated in accordance with the control signaling from the transmitting device and may decode a reconstructed signal based on performing the peak reconstruction on the signal using the soft metrics on symbol decisions, the clipping level, and the subset of the peaks clipped from the signal.

Wireless communications systems and methods related to wireless communications in a system are provided. A wireless communication device may compute a plurality of log-likelihood ratios (LLRs) based on a received communication signal. At least a first LLR and a second LLR of the plurality of LLRs represent the same first bit in the communication signal. The wireless communication device may combine the first LLR and the second LLR to decode the first bit and transmit a report indicating channel information. The channel information may be based at least in part on the plurality of LLRs before the combining of the first and second LLRs.

A method is for processing an analog signal coming from a transmission channel. The analog signal may include a useful signal modulated on a sub-set of carriers. The method may include analog-to-digital converting of the analog signal into a digital signal, and synchronization processing the digital signal. The synchronizing may include determining, in a time domain, a limited number of coefficients of a predictive filter from an autoregressive model of the digital signal, and filtering the digital signal in the time domain by a digital finite impulse response filter with coefficients based upon the limited number of coefficients to provide a filtered digital signal. The method may include detecting of an indication allowing a location in the frame structure to be identified, using the filtered digital signal and a reference signal.

A turbo equalization device includes equalization circuitry, which in operation, performs an equalization process M times on an input signal, M being an integer equal to or more than 1; counter circuitry, which in operation, counts an iteration number m that indicates a number of the performed equalization process, m being an integer equal to or more than 0 and equal to less than M; control circuitry, which in operation, determines an iteration number N of a decoding process for the m times equalization processed input signal according to the iteration number m of the equalization process, the decoding process using an error correcting code that uses a belief propagation algorithm, N being an integer equal to or more than 1; and decoding circuitry, which in operation, performs a decoding process N or less times on the m times equalization processed input signal.

Methods and apparatus for efficient demapping of constellations are described. In an embodiment, these methods may be implemented within a digital communications receiver, such as a Digital Terrestrial Television receiver. The method reduces the number of distance metric calculations which are required to calculate soft information in the demapper by locating the closest constellation point to the received symbol. This closest constellation point is identified based on a comparison of distance metrics which are calculated parallel to either the I- or Q-axis. The number of distance metric calculations may be reduced still further by identifying a local minimum constellation point for each bit in the received symbol and these constellation points are identified using a similar method to the closest constellation point. Where the system uses rotated constellations, the received symbol may be unrotated before any constellation points are identified.

Methods, systems, and devices are described for mitigating an unwanted increase in a coding rate of a wireless communication signal. A plurality of symbols including a transmitted codeword is received. The plurality of symbols including a first group of data symbols with a first modulation and coding scheme and a second group of data modulated pilot symbols with a second modulation and coding scheme. Applicable demodulation schemes are adaptively switched for each group of the plurality of symbols. The second group of data modulated pilot symbols are used in lieu of pilot symbols. The second modulation and coding scheme is a more reliable modulation and coding scheme than the first modulation and coding scheme.

A technique for de-mapping a point in a constellation diagram into a bit sequence is presented. The de-mapping provides for each bit of the bit sequence an output value with a sign of the output value indicating a bit value and a magnitude of the output value indicating probability information in the form of a distance to a decision boundary in the constellation diagram. A method aspect of the technique presented herein comprises receiving a signal indicative of a constellation point, wherein the constellation point represents a bit sequence having a most significant bit and at least one next significant bit, deriving a first output value for the most significant bit based on a first decision boundary, receiving a priori information, and deriving a second output value for the next significant bit based on the first output value, the a priori information and a second decision boundary.

A simplified but accurate soft-symbol determination process represents one of the advantages provided by the example embodiments disclosed herein. In this regard, a mapping function “maps” symbol estimates to corresponding soft symbol values, which may be used in interference mitigation, joint detection processing, etc. Whether the mapping function is implemented on-the-fly as a live calculation or is embodied in a look-up table, it advantageously operates on the symbol estimates directly, rather than requiring the derivation of corresponding soft bit values or the like, and it maps each symbol estimate to its “expected value,” i.e., the weighted sum of constellation point probabilities. Moreover, the mapping function may be changed dynamically—e.g., by using different look-up tables—to account for changing reception conditions and/or different modulation schemes or other signal parameters associated with the symbols being estimated and mapped to soft symbol values.

Circuits for producing signals representative of mean and variance estimations for quadrature amplitude modulation (QAM) are provided where the circuits comprise: sequentially repeated first circuit modules and sequentially repeated second circuit modules configured for producing updates in the corresponding estimation iterations. In one embodiment, a closest negative integer power of 2 is used as a substitute multiplicand when multiplying together two or more outputs of hyperbolic function generating units where the substituted for output is less than one. Size and complexity of the corresponding multiplier can then be reduced.

A system, method and device for wireless communication is provided. The method includes receiving, by a receiver, data from a transmitter, storing the data in the receiver, and determining, by the receiver, a probability of a bit stored in the data and a probability of a symbol based on the probability of the bit, wherein determining the probability of the bit includes moving a decision boundary associated with a constellation diagram.