Embodiments relate to systems, methods, and computer readable media to enable a wireless receiver are described. In one embodiment a wireless receiver includes a channel decoder and a Soft-Input Soft-Output Multiple-Input Multiple-Output detector (SISO MIMO detector). The SISO MIMO detector includes circuitry to generate soft symbol outputs for each of a plurality of received spatial streams, and circuitry to adjust a signal to noise plus interference ratio for the soft symbol outputs using channel statistics and using hard decisions from an output of the channel decoder. The channel decoder is configured to receive soft binary information generated from the soft symbol outputs from the SISO MIMO detector and perform these steps iteratively a number of times.

A base station includes a channel estimator, a scheduler, and a controller. The channel estimator estimates a channel matrix with respect to each of a plurality of terminals. The scheduler determines a transmission weight corresponding to each of the plurality of terminals on the basis of the channel matrix that is estimated by the channel estimator such that the transmission weight is orthogonal to a current channel matrix and a past channel matrix of a terminal that is a subject of interference. The controller controls, when the transmission weight is determined by the scheduler, the number of samples of the current channel matrix and the past channel matrix to which the transmission weight is to be orthogonal with respect to each of the terminals.

A base station includes a channel estimator, a scheduler, and a controller. The channel estimator estimates a channel matrix with respect to each of a plurality of terminals. The scheduler determines a transmission weight corresponding to each of the plurality of terminals on the basis of the channel matrix that is estimated by the channel estimator such that the transmission weight is orthogonal to a current channel matrix and a past channel matrix of a terminal that is a subject of interference. The controller controls, when the transmission weight is determined by the scheduler, the number of samples of the current channel matrix and the past channel matrix to which the transmission weight is to be orthogonal with respect to each of the terminals.

A data detection method, having the steps of: a. receiving a signal transmitted over a communication channel, the signal being representative of at least a stream of interfering symbols x.sub.k, each representing one or more bits of a transmitted message; b. filtering the received signal through at least a filter bank having at least a first filter representative of a linear response of the channel and a second filter representative of a non-linear response of the channel, and sampling the filtered signals at the symbol rate, thus obtaining respective sequences of filtered samples r.sub.k.sup.(1) r.sub.k.sup.(3); and c. jointly computing the a posteriori probabilities of N>1 consecutive symbols x.sub.k. A data detector for carrying out such a method, and a method of transmitting data over a nonlinear channel, optimizing spectral efficiency when data detection is performed using such a method is also provided.

A data detection method, having the steps of: a. receiving a signal transmitted over a communication channel, the signal being representative of at least a stream of interfering symbols x.sub.k, each representing one or more bits of a transmitted message; b. filtering the received signal through at least a filter bank having at least a first filter representative of a linear response of the channel and a second filter representative of a non-linear response of the channel, and sampling the filtered signals at the symbol rate, thus obtaining respective sequences of filtered samples r.sub.k.sup.(1) r.sub.k.sup.(3); and c. jointly computing the a posteriori probabilities of N>1 consecutive symbols x.sub.k. A data detector for carrying out such a method, and a method of transmitting data over a nonlinear channel, optimizing spectral efficiency when data detection is performed using such a method is also provided.

A method is disclosed for increasing the communication capacity of a shared ad-hoc wireless channel by using multiuser detection (MUD) to distinguish overlapping information transmitted simultaneously by a plurality of nodes. The transmitting nodes simultaneously provide parameter-estimating signals over separate, unshared, low-rate parameter channels generated using orthogonal frequencies, spread spectrum technology, or time multiplexing. Receiving nodes use these separate, non-overlapping parameter-estimating signals to estimate MUD-required signal parameters such as amplitude, phase, and frequency offset, thereby enabling use of lower complexity MUD receivers, because the parameters are not estimated in the presence of other interference. Node ID, spreading code type, and/or other information can also be transmitted over the parameter channels. Limiting the number of parameter channels can limit the maximum number of transmitting nodes. Amplitudes of parameter channel transmissions can be greater than communication channel transmissions by a known ratio. Parameter channels can be frequency-hopped for jam-resistance.

A method is disclosed for increasing the communication capacity of a shared ad-hoc wireless channel by using multiuser detection (MUD) to distinguish overlapping information transmitted simultaneously by a plurality of nodes. The transmitting nodes simultaneously provide parameter-estimating signals over separate, unshared, low-rate parameter channels generated using orthogonal frequencies, spread spectrum technology, or time multiplexing. Receiving nodes use these separate, non-overlapping parameter-estimating signals to estimate MUD-required signal parameters such as amplitude, phase, and frequency offset, thereby enabling use of lower complexity MUD receivers, because the parameters are not estimated in the presence of other interference. Node ID, spreading code type, and/or other information can also be transmitted over the parameter channels. Limiting the number of parameter channels can limit the maximum number of transmitting nodes. Amplitudes of parameter channel transmissions can be greater than communication channel transmissions by a known ratio. Parameter channels can be frequency-hopped for jam-resistance.

A controller is configured to control the adaptive notch filter and to execute a search technique (e.g., artificial intelligence (AI) search technique) to converge on filter coefficients and to recursively adjust the filter coefficients of the adaptive notch filter in real time to adaptively adjust one or more filter characteristics (e.g., maximum notch depth or attenuation, bandwidth of notch, or general magnitude versus frequency response of notch).

A controller is configured to control the adaptive notch filter and to execute a search technique (e.g., artificial intelligence (AI) search technique) to converge on filter coefficients and to recursively adjust the filter coefficients of the adaptive notch filter in real time to adaptively adjust one or more filter characteristics (e.g., maximum notch depth or attenuation, bandwidth of notch, or general magnitude versus frequency response of notch).

A radio frequency, RF, transmitter, comprises a digitally controlled oscillator, DCO, configured to generate an RF signal; and digital modulation circuitry connected to the DCO for modulation of the RF signal, and driven by an RF clock signal derived from the RF signal, wherein the digital modulation circuitry comprises a module configured to apply a compensation for modulation jitter due to the modulation circuitry being driven by the RF clock signal and a compensation for DCO non-linearity.