Abstract: A flexible and reconfigurable digital system (for example, a wireless modem) includes a set of sub-circuits. Each sub-circuit includes a task manager and an amount of configurable hardware circuitry for performing a type of operation on a data stream. The task manager of a sub-circuit can configure and control the configurable hardware of the sub-circuit. A central processor configures and orchestrates operation of the sub-circuits by maintaining a set of task lists in a tightly coupled memory. Each task list includes task instructions for a corresponding sub-circuit. The task manager of a sub-circuit reads task instructions from its task list and controls its associated hardware circuitry as directed by the instructions. A timestamp task instruction and a push task instruction and the task list architecture allow modem sub-circuits to be easily reconfigured to operate in accordance with either a first air interface standard or a second air interface standard.

Abstract: An apparatus operable in a wireless communication system, the apparatus may include an FFT symbol buffer and a demapping device. The FFT symbol buffer can feed FFT symbol data derived from received communication signals to a channel estimation device and a shared buffer. The channel estimation device can also provide intermediate data to the shared buffer. The intermediate data may be in tile form and can be derived from the FFT symbol data. Further, the intermediate data can be stored in the shared buffer. The demapping device can extract the intermediate data from the shared buffer in various forms including sub-packet form.

Abstract: Methods and apparatus for resolving frequency errors in a wireless device transitioning from a first communication network to a second communication network are disclosed. The methods and apparatus effect reception of a first and second channels from the second communication network where the first channel has known characteristics. The first channel is then decoding for a prescribed period and an initial frequency error value is determined based on the decoding of the first channel. A digital frequency rotator is then adjusted based on the initial frequency error value for purposes of decoding the second channel. The second channel is then decoded using the digital frequency rotator as adjusted based on the initial frequency error value, without further calculation of the frequency error.

Abstract: Techniques for scheduling measurements for cells in multiple (e.g., GSM and W-CDMA) wireless communication systems are described. GSM neighbor cells are categorized based on a number of states. The states are prioritized in a manner to achieve good performance. The GSM neighbor cells are thus assigned different priorities depending on their states. W-CDMA neighbor cells are prioritized relative to the states for GSM cells. All W-CDMA neighbor cells can be assigned the same state, given the same priority, and considered as “one” W-CDMA cell in the scheduling. A cell in the GSM or W-CDMA system is selected based on the priorities of the neighbor cells, and the selected cell is scheduled for measurement in the next available frame. The highest-ranking GSM or W-CDMA cell for each idle frame is thus granted use of that idle frame for measurement.

Abstract: Techniques for scheduling measurements for cells in multiple (e.g., GSM and W-CDMA) wireless communication systems are described. GSM neighbor cells are categorized based on a number of states. The states are prioritized in a manner to achieve good performance. The GSM neighbor cells are thus assigned different priorities depending on their states. W-CDMA neighbor cells are prioritized relative to the states for GSM cells. All W-CDMA neighbor cells can be assigned the same state, given the same priority, and considered as “one” W-CDMA cell in the scheduling. A cell in the GSM or W-CDMA system is selected based on the priorities of the neighbor cells, and the selected cell is scheduled for measurement in the next available frame. The highest-ranking GSM or W-CDMA cell for each idle frame is thus granted use of that idle frame for measurement.

Abstract: A received continuous phase modulation (CPM) signal (which is formed with a set of pulse shaping functions) is approximated as a phase shift keying (PSK) modulated signal (which is formed with just the dominant pulse shaping function having the largest energy). Channel estimation and data detection are performed in accordance with the CPM-to-PSK approximation. A signal power estimate and a noise power estimate are obtained for the received CPM signal and have errors due to the CPM-to-PSK approximation. The difference ? between the energy of the dominant pulse shaping function and the energy of the remaining pulse shaping functions is determined. An approximation error is estimated based on the signal power estimate and the difference ?. A C/I estimate for the received CPM signal is computed based on the signal power estimate, the noise power estimate, and the approximation error estimate.

Abstract: A wireless communication device (WCD) estimates frequency error by averaging frequency error estimates over multiple integration lengths to generate short-term and long-term averages. The WCD compares the short-term and long-term averages with short-term and long-term thresholds. The long-term thresholds are lower than the short-term threshold. If the average for any integration length exceeds its respective threshold, a frequency offset is determined and an oscillator frequency is adjusted based on that frequency offset. The use of both short-term and long-term thresholds facilitates responding quickly to relatively large changes in the frequency error, while ignoring smaller changes that may be indicative of noise in the system rather than actual changes in the frequency error.

Abstract: A received continuous phase modulation (CPM) signal (which is formed with a set of pulse shaping functions) is approximated as a phase shift keying (PSK) modulated signal (which is formed with just the dominant pulse shaping function having the largest energy). Channel estimation and data detection are performed in accordance with the CPM-to-PSK approximation. A signal power estimate and a noise power estimate are obtained for the received CPM signal and have errors due to the CPM-to-PSK approximation. The difference ? between the energy of the dominant pulse shaping function and the energy of the remaining pulse shaping functions is determined. An approximation error is estimated based on the signal power estimate and the difference ?. A C/I estimate for the received CPM signal is computed based on the signal power estimate, the noise power estimate, and the approximation error estimate.

Abstract: Soft metrics for multiple bursts transmitted at different times for a data packet are scaled, quantized, and rescaled prior to decoding. As each burst is received, input soft metrics for the burst are scaled with a scaling factor S(i), quantized based on a quantization scale factor Q(i), and stored in a buffer. The scaling factor and quantization scale factor are computed based on the statistics for the burst. After all bursts for the data packet have been received, the quantized soft metrics for each burst are rescaled based on the quantization scale factor Q(i) for that burst and a common scale factor to properly weight the soft metrics in the decoding process. The common scale factor is determined based on the quantization scale factors Q(i) for all bursts. The rescaled soft metrics for all bursts are requantized, deinterleaved, and decoded to obtain decoded data for the packet.

Abstract: A wireless communication device (WCD) estimates frequency error by averaging frequency error estimates over multiple integration lengths to generate short-term and long-term averages. The WCD compares the short-term and long-term averages with short-term and long-term thresholds. The long-term thresholds are lower than the short-term threshold. If the average for any integration length exceeds its respective threshold, a frequency offset is determined and an oscillator frequency is adjusted based on that frequency offset. The use of both short-term and long-term thresholds facilitates responding quickly to relatively large changes in the frequency error, while ignoring smaller changes that may be indicative of noise in the system rather than actual changes in the frequency error.

Abstract: Techniques for scheduling measurements for cells in multiple (e.g., GSM and W-CDMA) wireless communication systems are described. GSM neighbor cells are categorized based on a number of states. The states are prioritized in a manner to achieve good performance. The GSM neighbor cells are thus assigned different priorities depending on their states. W-CDMA neighbor cells are prioritized relative to the states for GSM cells. All W-CDMA neighbor cells can be assigned the same state, given the same priority, and considered as “one” W-CDMA cell in the scheduling. A cell in the GSM or W-CDMA system is selected based on the priorities of the neighbor cells, and the selected cell is scheduled for measurement in the next available frame. The highest-ranking GSM or W-CDMA cell for each idle frame is thus granted use of that idle frame for measurement.

Abstract: Soft metrics for multiple bursts transmitted at different times for a data packet are scaled, quantized, and rescaled prior to decoding. As each burst is received, input soft metrics for the burst are scaled with a scaling factor S(i), quantized based on a quantization scale factor Q(i), and stored in a buffer. The scaling factor and quantization scale factor are computed based on the statistics for the burst. After all bursts for the data packet have been received, the quantized soft metrics for each burst are rescaled based on the quantization scale factor Q(i) for that burst and a common scale factor to properly weight the soft metrics in the decoding process. The common scale factor is determined based on the quantization scale factors Q(i) for all bursts. The rescaled soft metrics for all bursts are requantized, deinterleaved, and decoded to obtain decoded data for the packet.