An integrated circuit includes a bit slicing circuit with a processing circuit. The processing circuit receives discrete frequency power estimates based on an S-FSK waveform received by an S-FSK receiver associated with the bit slicing circuit. The discrete frequency power estimates are representative of digital logic levels in a series of data frames modulated using S-FSK to form the S-FSK waveform. Each data frame including at least one word. Each word includes bit periods. The processing circuit receives SNR parameters that represent a dynamic SNR for the respective discrete frequency power estimates in relation to the series of data frames. The processing circuit selects a bit slicing technique from a set of available bit slicing techniques to generate data bit values for bit periods of the discrete frequency power estimates based on the SNR parameters. A method for performing bit slicing in an S-FSK receiver is also disclosed.

An integrated circuit includes a bit slicing circuit with a processing circuit. The processing circuit receives discrete frequency power estimates based on an S-FSK waveform received by an S-FSK receiver associated with the bit slicing circuit. The discrete frequency power estimates are representative of digital logic levels in a series of data frames modulated using S-FSK to form the S-FSK waveform. Each data frame including at least one word. Each word includes bit periods. The processing circuit receives SNR parameters that represent a dynamic SNR for the respective discrete frequency power estimates in relation to the series of data frames. The processing circuit selects a bit slicing technique from a set of available bit slicing techniques to generate data bit values for bit periods of the discrete frequency power estimates based on the SNR parameters. A method for performing bit slicing in an S-FSK receiver is also disclosed.

Methods, systems, and devices for wireless communication are described. A wireless communication device may receive multiple data streams from one or more users, associate the multiple data streams with different user groups, and identify modulation symbols for the users after reducing signal contribution from modulation symbols associated with different user groups. For example, the device may receive a signal including multiple spatial streams, partition the data streams into different user groups, and determine a set of sequences from channel characteristics associated with the respective user groups. The wireless communication device may then apply the sequences to the received signal and to values associated with the channel characteristics. Subsets of values may be selected following the application of the sequences, and from the subsets of values, the wireless communication device may identify the sets of modulation symbols associated with one or more of the user groups.

A method for determining the time of receipt by a radio receiver of a binary coded radio message emitted by a sender. A radio signal containing the message is received by the receiver. An analog electrical signal is generated, sampled and optionally demodulated. The data content of the message is determined based upon the demodulated signal as a stream of data bits. The stream of data bits comprises a predetermined signal element whose time of receipt is determined. A digitally stored, constructed comparison signal is created based upon the stream of data bits. The constructed comparison signal is constructed to correspond to the sampled signal, in that a time variable which maximizes a correlation between the constructed comparison signal and the sampled signal is determined, and in that the time variable is then used to correct the time determination of the receipt of the predetermined signal element.

A method for determining the time of receipt by a radio receiver of a binary coded radio message emitted by a sender. A radio signal containing the message is received by the receiver. An analog electrical signal is generated, sampled and optionally demodulated. The data content of the message is determined based upon the demodulated signal as a stream of data bits. The stream of data bits comprises a predetermined signal element whose time of receipt is determined. A digitally stored, constructed comparison signal is created based upon the stream of data bits. The constructed comparison signal is constructed to correspond to the sampled signal, in that a time variable which maximizes a correlation between the constructed comparison signal and the sampled signal is determined, and in that the time variable is then used to correct the time determination of the receipt of the predetermined signal element.

A method for calibrating the DC operating point of a PWM receiver circuit is disclosed. The PWM receiving circuit includes an envelop detector having a first resistor string, and includes a bias circuit having a second resistor string and a plurality of switches. The second resistor string is coupled between a supply voltage and a reference voltage and functions as a voltage divider. Each switch, when closed, accesses a second voltage at a node of the second resistor string connected to the closed switch. To perform the calibration process, the plurality of switches is closed one at a time, and the second voltage is compared with a first voltage at a first node of the first resistor string. The switch that, when closed, produces the smallest difference between the first voltage and the second voltage remains closed after the calibration process, and is used for demodulating the PWM signal.

A method for calibrating the DC operating point of a PWM receiver circuit is disclosed. The PWM receiving circuit includes an envelop detector having a first resistor string, and includes a bias circuit having a second resistor string and a plurality of switches. The second resistor string is coupled between a supply voltage and a reference voltage and functions as a voltage divider. Each switch, when closed, accesses a second voltage at a node of the second resistor string connected to the closed switch. To perform the calibration process, the plurality of switches is closed one at a time, and the second voltage is compared with a first voltage at a first node of the first resistor string. The switch that, when closed, produces the smallest difference between the first voltage and the second voltage remains closed after the calibration process, and is used for demodulating the PWM signal.

In 5G and 6G, each message element of a message is transmitted with a constant amplitude level. Disclosed herein is a more resource-efficient modulation scheme in which each message element is modulated to two of the amplitude levels, with a first amplitude level in the first half of a message element, and a second amplitude level in the second half. The information density of the message is thereby doubled, saving time and resources. The transition between the first and second amplitude levels can be abrupt, as in a square wave, or ramped, as in a linear ramp function. The changing amplitude may cause a frequency shift; however the transmitter can calculate that shift and apply a frequency correction to each message element to compensate. The changing amplitude can also deposit energy in adjacent subcarriers; however the receiver can calculate that energy and subtract it from the adjacent subcarriers before demodulating.

In 5G and 6G, each message element of a message is transmitted with a constant amplitude level. Disclosed herein is a more resource-efficient modulation scheme in which each message element is modulated to two of the amplitude levels, with a first amplitude level in the first half of a message element, and a second amplitude level in the second half. The information density of the message is thereby doubled, saving time and resources. The transition between the first and second amplitude levels can be abrupt, as in a square wave, or ramped, as in a linear ramp function. The changing amplitude may cause a frequency shift; however the transmitter can calculate that shift and apply a frequency correction to each message element to compensate. The changing amplitude can also deposit energy in adjacent subcarriers; however the receiver can calculate that energy and subtract it from the adjacent subcarriers before demodulating.

Embodiments of the invention provide a decoder for decoding a signal received through a transmission channel in a communication system, said signal comprising a vector of information symbols, said transmission channel being represented by a channel matrix comprising column vectors, said information symbols carrying information bits, wherein the decoder comprises: a transformation unit (401) configured to determine a set of auxiliary channel matrices, each auxiliary channel matrix being determined by performing a linear combination of at least one of the column vectors of said channel matrix; a decomposition unit (407) configured to determine a decomposition of each auxiliary channel matrix into an upper triangular matrix and an orthogonal matrix; a matrix selection unit (409) configured to select at least one auxiliary channel matrix among said set of auxiliary channel matrices depending on a selection criterion related to the components of said upper triangular matrices.

The decoder being configured to determine an auxiliary signal by multiplying the transpose of the orthogonal matrix corresponding to said selected auxiliary channel matrix by said received signal, the decoder being configured to determine at least one estimate of said vector of information symbols from said auxiliary signal and from the upper triangular matrix corresponding to said selected auxiliary channel matrix by applying a decoding algorithm.