Abstract: Disclosed are systems, methods and computer program products for secure rebooting and debugging a peripheral subsystem of a system on a chip (SoC) device. According to one aspect of the method, when an application processor of the SoC device detects crash of the peripheral subsystem, the application processor loads a secure boot agent into SoC memory. The secure boot agent is configured to access a secure memory region of the peripheral subsystem containing memory dump data associated with the peripheral subsystem. The secure memory region is inaccessible to the application processor. The Secure boot agent encrypts the memory dump data in the secure memory region and opens the secure memory region for access to the application processor. The application processor accesses the secure memory region and collects the encrypted memory dump data. The application processor then forwards the encrypted memory dump data to a third party for debugging purposes.

Abstract: A method and apparatus are disclosed for determining the presence of adjacent channel interference. Received digital signals are processed to detect the existence of strong channels adjacent to the channel of interest and control signals may be generated based on the detection of strong adjacent channels. The control signals are then used to adjust the signal power of the received signals.

Abstract: A ZIF direct-conversion OFDM receiver capable of estimating and correcting an I/Q imbalance in a baseband signal. A complex down-conversion is performed on a received signal r(t). The received signal r(t) is divided into an In-phase signal (I) and Quadrature-phase signal (Q). An I/Q imbalance is introduced by the local oscillator such that the I/Q imbalance includes an amplitude imbalance factor (?) and phase imbalance factor (?). The I and Q signals are amplified, filtered and digitized. The digitized I and Q signals are processed via a Fast Fourier Transform (FFT). An I/Q compensation algorithm estimates the values of the amplitude imbalance factor (?) and, the phase imbalance factor (?) based on a time expectation calculation. The imbalance factors are applied to the baseband signal to recover the signal of interest x(t). The OFDM receiver outputs the signal of interest x(t) to an information display device.

Abstract: A receiver for receiving an orthogonal frequency division multiplexed (OFDM) digital video broadcast (DVB) signal including OFDM symbol sets including data symbols and pilot symbols transmitted using a plurality of sub-carriers, the OFDM DVB signal being transmitted toward the receiver via a transmission channel, the receiver including an input module configured to receive the OFDM DVB signal via the transmission channel, and a channel estimation module coupled to the input module and configured to calculate channel estimates of the transmission channel by performing Fourier transforms on the OFDM symbol sets to produce transformed symbol sets in the frequency domain and by performing minimum mean square error (MMSE) equalization on the transformed symbol sets using a sub-set of the pilot symbols in the OFDM DVB signal.

Abstract: An apparatus and method are described that provide an optimal blind channel estimation approach for a differential quadrature phase shift keying (DQPSK) modulation communication receiving system. The described blind channel estimation technique takes advantage of the characteristics of DQPSK constellations and the fact that estimates of relative channel phase distortion, and not absolute channel phase distortion, are sufficient for a DQPSK demodulation scheme. The described channel estimation approach provides low complexity, offers improved demodulation performance, and is theoretically optimal. It is particularly useful in existing DQPSK-based communications protocols that do not provide sufficient reference symbols for channel estimation.

Abstract: A receiver employs iterative decoding of packet data, where the packet data represents a data frame encoded with at least two logical dimensions. A logical dimension refers to a layer, or sub-layer, of a layered network architecture. Consequently, a first logical dimension of encoding might refer to error detection in a packet frame at the data link layer, while a second logical dimension of coding might refer to error detection/correction encoding at a physical layer. For example, a data frame might be divided into several packets, each with a corresponding cyclic redundancy check (CRC) value as coding in the first logical dimension, which are then transmitted with a convolutional code as coding in the second logical dimension. The receiver performs iterative decoding in the first and second logical dimensions until either i) all errors are identified and corrected or ii) another type of stopping condition is met.

Abstract: A method for synchronizing a receiver to a received signal begins by down-converting the received signal to a first baseband signal. A coarse frequency offset (CFO) of the first baseband signal is determined and is applied to the down-converting of the received signal to a second baseband signal. A fine frequency offset (FFO) of the second baseband signal is determined. The receiver is synchronized to the received signal using the CFO and the FFO.

Abstract: An apparatus and method is described that provide an efficient blind channel estimation approach for PSK and DPSK modulated multicarrier communication systems. With the requirement that the channel phase difference between any two adjacent carriers is smaller than one half of the minimum phase difference between two symbols of the PSK or DPSK constellation, a low-complexity deterministic approach to channel estimation is devised. This approach is highly effective, robust, and particularly useful for time varying channels with low AWGN noise.

Abstract: A method of fast stream switching including receiving at least one first stream at a device corresponding to at least one first program, wherein the device employs dynamic power management and is operating at a first power level; activating a selection panel; receiving a plurality of streams corresponding to a plurality of programs; and adjusting to a second power level. After a stream is selected, the non-selected streams may be deactivated and the device may return to the first power level.

Abstract: An apparatus and method is described that provides optimal D-PSK demodulation based on the distribution of phase differences between successive D-PSK symbols. A plurality of D-PSK data symbols are received, and each symbol is characterized by a real component and an imaginary component. An angle of correlation between any two successive symbols is calculated. A variance of correlation angles is obtained by using data symbols or pilot symbols, if available. The probability of the correlation angle being each of possible phase difference according the D-PSK constellation is then determined. From the probabilities of the particular correlation angle, a probability of each input bit being a “0” or “1” is determined.

Abstract: A method of dynamic power management in a time division multiple access (TDMA) system. The method comprising comparing each of a plurality of streams; grouping each of the plurality of streams into a plurality of powergroups, wherein each of the plurality of powergroups may comprise multiple streams, scheduling a burst transmission based on the plurality of powergroups; and adjusting the power stage based on the plurality of powergroups, wherein the system is configured to turn off selected components based on the power stage and the scheduled burst transmissions.

Abstract: A receiver for receiving an orthogonal frequency division multiplexed (OFDM) digital video broadcast (DVB) signal including OFDM symbol sets including data symbols and pilot symbols transmitted using a plurality of sub-carriers, the OFDM DVB signal being transmitted toward the receiver via a transmission channel, the receiver including an input processor configured to receive the OFDM DVB signal via the transmission channel and to perform a Fourier transform on the OFDM DVB signal to provide a frequency-domain signal, a channel estimation processor coupled to the input processor and configured to calculate final channel estimates, the channel estimation processor being configured to perform time-domain prediction on the frequency-domain signal to provide established sub-carriers that each have corresponding initial channel estimates, and perform minimum mean square error (MMSE) equalization on the frequency-domain signal using the initial channel estimates that correspond to a sub-set of the established sub-c

Abstract: A trellis decoder decodes a stream of encoded symbols, including symbols of a first type (e.g. symbols encoded with a first trellis code) and symbols of a second type (e.g. encoded with a second, more robust, trellis code), without storing path indicators along a trellis for symbols of the first type. In this way, limited memory may be used to store path indicators along the trellis for symbols of the second type. This allows for more accurate decoding of the symbols of the second type. For transitions from symbols of the second type to symbols of the first type, states of the trellis decoder may be stored. In this way, paths may be traced back along the trellis for trellis decoding, without the path indicators for the symbols of the first type.

Abstract: A method of estimating a time variant Orthogonal Frequency Division Multiplexing (OFDM) while eliminating Inter-carrier Interference (ICI) is disclosed, where the time variant channel matrix is estimated at channel taps using a Basis Expansion Model (BEM). The BEM method decomposes the time variant channel into a group of basis functions in the frequency domain. Coefficients are estimated using a sub-space tracking algorithm that decreases the dimensions of the coefficient matrix allowing for simpler calculation of the estimated signal. The coefficients matrix is estimated using a conjugate gradient iterative method that may be stopped after 6-8 iterations to arrive at an acceptable estimation. Finally, the transmitted data is estimated, again using the conjugate gradient method iteratively, wherein the conjugate gradient method is stopped after a small number of iterations.

Abstract: A D-PSK demodulator utilizes a two-layer coherent approach to estimate the phase shift of adjacent symbols. There is generated a probability set of each received symbol being one of possible constellation values. There is also generated a probability set of each of possible phase difference between two adjacent symbols. This probability set is then converted into soft bit information according to specific mathematical operation.

Abstract: One method includes estimating, by a lost packet determination logic, an expected number of packets, expected to be received within a time interval, based on packet arrival speed; and determining a number of lost packets by using the expected number of packets and a packet counter wherein the packet counter counts a plurality of received packets. The method may further include comparing the expected number of packets to the packet counter and determining that the expected number of packets is greater than the packet counter; and then using the expected number of packets and the packet counter to determine the actual number of lost packets, where the actual number of lost packets exceeds the packet counter maximum. The methods may also introduce erasures when there is uncertainty of whether some packets or bytes are in error, such that a simplified erasure-based Reed-Solomon decoder may be used.

Abstract: A trellis decoder decodes a stream of encoded symbols, including symbols of a first type (e.g. symbols encoded with a first trellis code) and symbols of a second type (e.g. encoded with a second, more robust, trellis code), without storing path indicators along a trellis for symbols of the first type. In this way, limited memory may be used to store path indicators along the trellis for symbols of the second type. This allows for more accurate decoding of the symbols of the second type. For transitions from symbols of the second type to symbols of the first type, states of the trellis decoder may be stored. In this way, paths may be traced back along the trellis for trellis decoding, without the path indicators for the symbols of the first type.

Abstract: A method and apparatus are disclosed for determining the presence of adjacent channel interference. Received digital signals are processed to detect the existence of strong channels adjacent to the channel of interest and control signals may be generated based on the detection of strong adjacent channels. The control signals are then used to adjust the signal power of the received signals.

Abstract: A method for synchronizing a receiver to a received signal begins by down-converting the received signal to a first baseband signal. A coarse frequency offset (CFO) of the first baseband signal is determined and is applied to the down-converting of the received signal to a second baseband signal. A fine frequency offset (FFO) of the second baseband signal is determined. The receiver is synchronized to the received signal using the CFO and the FFO.

Abstract: A trellis decoder decodes a stream of encoded symbols, including symbols of a first type (e.g. symbols encoded with a first trellis code) and symbols of a second type (e.g. encoded with a second, more robust, trellis code), without storing path indicators along a trellis for symbols of the first type. In this way, limited memory may be used to store path indicators along the trellis for symbols of the second type. This allows for more accurate decoding of the symbols of the second type. For transitions from symbols of the second type to symbols of the first type, states of the trellis decoder may be stored. In this way, paths may be traced back along the trellis for trellis decoding, without the path indicators for the symbols of the first type.