Abstract: In a signal-based gain control scheme, one or more gain levels used for processing signals are selected based on characteristics of previously received signals. For example, different gain levels may be used to receive sets of signals whereupon certain characteristics of the received sets of signals are determined. One or more gain levels are then selected based on these characteristics whereby another signal is processed based on the selected gain level(s). In some aspects, the signal-based gain control scheme may be employed to facilitate two-way ranging operations between two devices. For example, leading edge detection may involve determining a characteristic of a received signal, determining a threshold based on the characteristic, and identifying a leading edge associated with the received signal based on the threshold. In some aspects, the signal-based gain control scheme may be employed in an ultra-low power pulse-based communication system (e.g., in ultra-wideband communication devices).

Abstract: Methods of detecting a pulse sequence in a received signal are disclosed, each of which entails operating on samples of the received signal. One method entails determining a correlation of samples with a reference sequence, and detecting the pulse sequence based on the correlation. Another method entails selecting a reference sample associated with a pulse, and detecting the pulse sequence by analyzing samples based on one or more lengths of a time hopping interval and the reference sample. Another method entails selecting a reference sample associated with non-restricted time hopping intervals, and detecting the pulse sequence by analyzing samples that are based on substantially one or more lengths of a half pulse interval and the reference sample. Further, disclosed is a method of determining a timing drift by selecting samples, determining a time delay between the selected samples, and determining the timing drift based on the determined time delay and an expected time delay.

Abstract: A multiple access technique for a wireless communication system establishes separate channels by defining different time intervals for different channels. In a transmitted reference system different delay periods may be defined between transmitted reference pulses and associated data pulses for different channels. In addition, a multiple access technique may employ a common reference pulse for multiple channels in a transmitted reference system. Another multiple access technique assigns different pulse repetition periods to different channels. One or more of these techniques may be employed in an ultra-wide band system.

Abstract: An apparatus is disclosed having a receiver configured to communicate, by a first apparatus, with a second apparatus in a first mode; determine side information by the first apparatus based on the communication during the first mode; and store the side information by the first apparatus for communication in a second mode with the second apparatus, wherein the first and second modes of communication have different date rates. A method for wireless communications is also disclosed.

Abstract: Frequency and phase of an output signal is adjusted to track an input signal. A control signal is adjusted to control a frequency of an oscillating signal from which the output signal is derived. In some aspects the frequency of the oscillating signal is adjusted by reconfiguration of reactive circuits coupled to an oscillator circuit. Phase of the output signal may be adjusted based on comparison of the oscillating signal with an adjustable threshold. For example, the adjustable threshold may comprise an adjustable bias signal for a transistor circuit whereby the oscillating signal is provided as an input to the transistor circuit and the output of the transistor circuit provides the output signal.

Abstract: A tunable delay line is calibrated to maintain the delay of the delay line at a desired value or within a desired range of values. In some aspects a signal is passed through a delay line multiple times so that the cumulative delay of the signal through the delay line (e.g., as indicated by a count) may be calculated over a period of time. The count is compared with an expected count and, based on this comparison, the delay of the delay line is adjusted as necessary. In some aspects the signal may comprise a digital signal. In some aspects a delay through a delay line may be calculated based on analysis of amplitude changes in a signal caused by a phase shift imparted on the signal by the delay line. In some aspects a delay line is incorporated into a transmitted reference system to generate and/or process transmitted reference signals.

Abstract: A method of transmitting and receiving data frames using pulses is disclosed. According to the transmitting method, a first signal is transmitted including one or more bursts of pulses during a first portion of a transmission frame, and not transmitting the first signal during a second portion of the transmission frame. The not transmitting the first signal may include maintaining one or more silence periods for the second portion of the transmission frame, or transmitting a second signal distinct from the first signal. According to the receiving method, a signal including one or more bursts of pulses is received during a first portion of a transmission frame, an analysis of the one or more bursts of pulses is performed, and the transmission frame is detected based on the analysis of the one or more bursts of pulses.

Abstract: A multiple access technique for a wireless communication system establishes separate channels by defining different time intervals for different channels. In a transmitted reference system different delay periods may be defined between transmitted reference pulses and associated data pulses for different channels. In addition, a multiple access technique may employ a common reference pulse for multiple channels in a transmitted reference system. Another multiple access technique assigns different pulse repetition periods to different channels. One or more of these techniques may be employed in an ultra-wide band system.

Abstract: An apparatus and method for communications is disclosed. The apparatus includes a slicer configured to generate samples of a signal carrying information, and a demodulator having a digital integrator configured to integrate the samples, the demodulator being further configured to recover from the integrated samples data representative of the information carried by the signal.

Abstract: A tunable delay line is calibrated to maintain the delay of the delay line at a desired value or within a desired range of values. In some aspects a signal is passed through a delay line multiple times so that the cumulative delay of the signal through the delay line (e.g., as indicated by a count) may be calculated over a period of time. The count is compared with an expected count and, based on this comparison, the delay of the delay line is adjusted as necessary. In some aspects the signal may comprise a digital signal. In some aspects a delay through a delay line may be calculated based on analysis of amplitude changes in a signal caused by a phase shift imparted on the signal by the delay line. In some aspects a delay line is incorporated into a transmitted reference system to generate and/or process transmitted reference signals.

Abstract: An apparatus for communications configured to support first and second spread-spectrum channels, each of the first and second channels being based on a different pseudorandom sequence. The apparatus further configured to select one of the first and second channels for communications to avoid a collision of information that would otherwise occur based on their pseudorandom sequences.

Abstract: An apparatus and method for wireless communications configured to receive simultaneous transmissions from a plurality of wireless devices, with each of the transmissions having a reference signal, acquire the reference signals and, based on information obtained from the acquisition of the reference signals, select the transmission from one of the wireless devices for timing synchronization and decoding.

Abstract: A tunable delay line is calibrated to maintain the delay of the delay line at a desired value or within a desired range of values. In some aspects a signal is passed through a delay line multiple times so that the cumulative delay of the signal through the delay line (e.g., as indicated by a count) may be calculated over a period of time. The count is compared with an expected count and, based on this comparison, the delay of the delay line is adjusted as necessary. In some aspects the signal may comprise a digital signal. In some aspects a delay through a delay line may be calculated based on analysis of amplitude changes in a signal caused by a phase shift imparted on the signal by the delay line. In some aspects a delay line is incorporated into a transmitted reference system to generate and/or process transmitted reference signals.

Abstract: Relatively short turnaround times are provided in conjunction with two-way ranging to, for example, facilitate accurate ranging measurements when the relative clock drift between ranging nodes (e.g., devices) is relatively high. In some aspects, relatively short turnaround times are achieved through the use of a symmetric channel that is defined to enable concurrent transmission of ranging messages between nodes. For example, a symmetric channel may be established by configuring the nodes to receive one or more pulses associated with a received ranging message in between pulse transmissions associated with a transmitted ranging message. In this way, one node may send a ranging timestamp shortly after the other nodes sends its ranging timestamp, thereby mitigating the impact of the clock drift on the ranging measurements. In some aspects the pulses may comprise ultra-wideband pulses.

Abstract: A signaling scheme employs transmitted reference pulses having varying phase. The phase of the reference pulses may be varied in a random manner or in accordance with a data stream. In some aspects a transmitter modulates the phase of the reference pulses to encode an additional data stream in a transmitted reference signal. In some aspects these techniques are employed in a heterogeneous network including coherent and non-coherent receivers. In some aspects these techniques may be employed in an ultra-wide band system.

Abstract: Adverse effects associated with collisions in a wireless communication system are mitigated by defining one or more values for receive data. Here, data that is expected to be received during a data transmission may be set to a defined value. In some cases the defined value is a predefined value (e.g., zero or some other value). In some cases the defined value is based on noise and/or signals levels in the system. In some implementations a device may define receive data values for a period of time during which data is expected to be received and during which a transmission occurs. In some aspects a hybrid on-off keying scheme is employed to determine received data values.

Abstract: An apparatus for data communication that receives a plurality of pulses from a remote communications device, determines a pulse puncturing rate based on the pulses, and punctures or discards subsequent pulses based on the pulse puncturing rate. During intervals when punctured pulses are expected, the apparatus operates in a lower power consumption mode for the purpose of conserving power. In another aspect, a receiving apparatus determines the pulse puncturing rate based on received pulses, and transmits the pulse puncturing rate information to a transmitting apparatus. In response, the transmitting apparatus sends a subset of the pulses it would have transmitted based on the pulse puncturing rate. Because the receiving apparatus receives fewer pulses (e.g., a subset), the receiving apparatus may operate in a lower power consumption mode for longer periods in order to conserve power.

Abstract: An apparatus and method for performing automatic gain control in a receiver are disclosed. The apparatus may include an amplifier, and the gain control may be based on an output from the amplifier during a time period in which a target signal is not present at the output of the amplifier.

Abstract: An apparatus and method for communications is disclosed. The apparatus includes a slicer configured to generate samples of a signal carrying information, and a demodulator having a digital integrator configured to integrate the samples, the demodulator being further configured to recover from the integrated samples data representative of the information carried by the signal.

Abstract: Phase of an output signal is based on comparison of an oscillating signal with an adjustable threshold. Here, adjustment of the threshold results in a corresponding adjustment of the phase of the output signal. For example, the adjustable threshold may comprise an adjustable bias signal for a transistor circuit whereby the oscillating signal is provided as an input to the transistor circuit and the output of the transistor circuit provides the output signal. In some aspects these phase adjustment techniques may be employed to provide one or more tunable multiphase clocks.