Abstract: In a system and method for wireless communication with a transmitter and a receiver, the transmitter is operable to wirelessly transmit digital information to the receiver with a plurality of data transmission rates using a modulation format, wherein the digital information is transmitted using a transmission frame including a header part and a payload part, and the header part comprises a preamble, wherein the modulation format is the same for all data transmission rates and wherein the data transmission rate is at least encoded into the preamble of the frame, and wherein the receiver is configured to determine the data transmission rate when receiving the preamble.

Abstract: An inexpensive and low-power demand RF wireless device having data acquisition capabilities may be used for simple applications such as a standalone data repeater or a standalone data acquisition node without requiring a host microcontroller unit (MCU) or programmable logic for control of the wireless device.

Abstract: A two stage process is applied for recovering the modulating content from the received I-Q waveforms of a MSK modulated signal. In the first stage, at each incoming symbol the I-Q waveform segments of the input belonging to the three most recently received symbols are used in hypothesis testing. A matched filter bank produces ratings for each of the possible three symbol modulating patterns in proportion to the likelihood that the combination in question may have produced the current but by now impaired input segment. While the three symbol window slides symbol-by-symbol over the input the successive hypothesis tests are not independent as each symbol is involved in three consecutive tests. The dependence thus created lays the foundation and provides the branch metrics for applying the Viterbi algorithm for the determination of the modulating symbols in the second stage.

Abstract: Angle of arrival (AoA) in a radio frequency (RF) network having radio devices at unknown positions is determined by using a specially built RF locator device. Any kind of modulation comprising, for example but not limited to, Direct Sequence Spread Spectrum (DSSS) symbols can be decoded by the RF locator device using complex correlation. The RF locator device is connected to an antenna array with multiple antenna elements that are switched between DSSS symbols. The RF locator device determines correlation magnitude and angle data of the radio device for further processing. Collecting DSSS symbols with CFO compensated correlation magnitude and phase results from different locations enables electrical beam forming for determining the AoA by sweeping this beam around an angle of view of the antenna array. This AoA determination may be performed on multiple channels and packets to reduce the effects of multi-path propagation.

Abstract: Carrier frequency offset is determined by sample-to-sample phase shifts of a digital radio signal. The CFO range is divided into a number of intervals and creates as many parallel derived streams as there are interval endpoints by pre-compensating (“back rotating”) the input by the sample-to-sample phase shift corresponding to the particular endpoint. Magnitude and phase values are computed of the correlation of a preamble pattern period with the preamble segment of each derived stream in parallel. The largest resulting magnitude value(s) are used to zoom in on the actual CFO present in the input stream. Improved accuracy in the presence of noise may be obtained by repeating the search for a shorter interval centered on the prior CFO value. Final CFO and phase values from corresponding correlation computations then determine the actual CFO and corresponding sample-to-sample phase shift to be applied for pre-compensation (“back rotation”) in an open-loop AFC.

Abstract: Carrier frequency offset (CFO) between a transmitter and receiver signaling at 2 Mbps data rate with a 11110000 pattern as the preamble period is corrected within one preamble time period using free-running coarse and fine carrier frequency offset estimations. Two estimates for the CFO are computed, coarse and fine. The fine one is computationally accurate but may not be correct because of a potential wrap at ±180° in the computation. The coarse one is not accurate but delivers the approximate CFO value without wrap over. The comparison between the coarse and fine estimates thus may be used to detect a wrap over in the fine estimate and modify the fine estimate accordingly. Thereafter the compensated fine CFO estimation is used for carrier frequency offset (CFO) compensation.

Abstract: An inexpensive and low-power demand RF wireless device having data acquisition capabilities may be used for simple applications such as a standalone data repeater or a standalone data acquisition node without requiring a host microcontroller unit (MCU) or programmable logic for control of the wireless device.

Abstract: In a system and method for wireless communication with a transmitter and a receiver, the transmitter is operable to wirelessly transmit digital information to the receiver with a plurality of data transmission rates using a modulation format, wherein the digital information is transmitted using a transmission frame including a header part and a payload part, and the header part comprises a preamble, wherein the modulation format is the same for all data transmission rates and wherein the data transmission rate is at least encoded into the preamble of the frame, and wherein the receiver is configured to determine the data transmission rate when receiving the preamble.

Abstract: Carrier frequency offset (CFO) between a transmitter and receiver signaling at 2 Mbps data rate with a 11110000 pattern as the preamble period is corrected within one preamble time period using free-running coarse and fine carrier frequency offset estimations. Two estimates for the CFO are computed, coarse and fine. The fine one is computationally accurate but may not be correct because of a potential wrap at ±180° in the computation. The coarse one is not accurate but delivers the approximate CFO value without wrap over. The comparison between the coarse and fine estimates thus may be used to detect a wrap over in the fine estimate and modify the fine estimate accordingly. Thereafter the compensated fine CFO estimation is used for carrier frequency offset (CFO) compensation.

Abstract: A two stage process is applied for recovering the modulating content from the received I-Q waveforms of a MSK modulated signal. In the first stage, at each incoming symbol the I-Q waveform segments of the input belonging to the three most recently received symbols are used in hypothesis testing. A matched filter bank produces ratings for each of the possible three symbol modulating patterns in proportion to the likelihood that the combination in question may have produced the current but by now impaired input segment. While the three symbol window slides symbol-by-symbol over the input the successive hypothesis tests are not independent as each symbol is involved in three consecutive tests. The dependence thus created lays the foundation and provides the branch metrics for applying the Viterbi algorithm for the determination of the modulating symbols in the second stage.

Abstract: Carrier frequency offset (CFO) is determined by sample-to-sample phase shifts of a digital radio signal. The CFO range is divided into a number of intervals and creates as many parallel derived streams as there are interval endpoints by pre-compensating (“back rotating”) the input by the sample-to-sample phase shift corresponding to the particular endpoint. Magnitude and phase values are computed of the correlation of a preamble pattern period with the preamble segment of each derived stream in parallel. The largest resulting magnitude value(s) are used to zoom in on the actual CFO present in the input stream. Improved accuracy in the presence of noise may be obtained by repeating the search for a shorter interval centered on the prior CFO value.