摘要:
System and method for determining a separation between communicating devices. A preferred embodiment comprises a first device transmitting a signal over multiple subbands to a second device, the second device determining a timing for the signal by processing the signal in each subband separately. The second device then transmits a signal back to the first device along with timing information (again, over multiple subbands). The first device then determines a timing for the signal and by determining a difference in the timing information provided by the second device and timing information it determines, the first device can compute the separation between it and the second device. The use of multiple subbands can dedicate more bandwidth to the transmission of the signal, permitting greater resolution.
摘要:
Quasi-parallel read/write interleaver architecture for data blocks by sequential spreading of variable size data subblocks into memory banks with bank address contention initiating the next data subblock. Iterative Turbo decoders with MAP decoders use such quasi-parallel interleavers and deinterleavers.
摘要:
A touch screen system includes a capacitive touch screen (1) including a plurality of row conductors (7-1,2 . . . n) and a column conductor (5-1). A plurality of cotemporaneous orthogonal excitation signals (S1(t), S2(t) . . . Sn(t)) are simultaneously driven onto the row conductors, respectively. The capacitively coupled signals on the column conductor may be influenced by a touch (10) on the capacitive touch screen. Receiver circuitry (50) includes a sense amplifier (21-1) coupled to generate an amplifier output signal (r1(t)) in response to signals capacitively coupled onto the column conductor. WHT-based circuitry (35) determines amounts of signal contribution capacitively coupled by each of the excitation signals, respectively, to the amplifier output signal.
摘要:
Embodiments of the invention provide an interleaver design and header fields for ITU-T G.hnem. The header may comprise two parts that are separately encoded. A common header segment is encoded alone, and an embedded header segment is encoded with payload data. The interleaver operates on blocks having a size based upon a total number of input bits in an FEC codeword block, a total number of bits loaded on symbols that span a half mains cycle, or a maximum fragment size of 3072 bits. The blocks may be repeated before interleaving. Each block and its repetitions may be interleaved together, such as for header data, or each block and repetition may be interleaved separately, such as for payload data. Cyclic padding may be used on each block to create an integer number of symbols for transmission.
摘要:
A device for communicating digital data over power lines includes a power line interface for transmitting data over at least one band of frequencies. An orthogonal frequency division multiplexing (OFDM) modulation unit generates OFDM symbols using a set of tones for the frequency band. A preamble generation unit generates preamble sequences for the frequency band by using the set of tones used by the OFDM modulation unit. The tones used by the preamble generation unit have a constant magnitude, and a set of phases obtained by quantizing to a small alphabet the phase of a set of tones obtained by taking an IFFT of a portion of a preamble used by a non-interoperable powerline access device. The device may transmit on two or more bands using a sampling frequency clock, wherein a lower band clock frequency is equal to or an integer divisor of a higher band clock frequency.
摘要:
A wireless communication transmission channel estimation by initial data exchange to determine calibration factors to apply to tracked channel estimations from received transmissions.
摘要:
The present invention provides an enhanced channel estimator for use with an orthogonal frequency division multiplex (OFDM) receiver employing scattered pilot channel estimates. In one embodiment, the enhanced channel estimator includes a time interpolation estimator configured to provide time-interpolation channel estimates having at least one image for a portion of carriers having the scattered pilot channel estimates. The enhanced channel estimator also includes a frequency interpolation estimator coupled to the time interpolation estimator and configured to provide frequency-interpolation channel estimates for each carrier based on image suppression through balanced-error filtering.
摘要:
A system and method for channelization and data multiplexing in ultra-wideband (UWB) wireless communication system is described. The spectrum allocated for UWB in a multi-band OFDM (orthogonal frequency division multiplex) system is subdivided into various bands. A set of time frequency codes (TFC's) is defined, wherein each code specifies one of a plurality of unique band versus time sequences for a particular band group, for sequential data symbols of a given piconet. The separation of data words from multiple devices or multiple simultaneously operating piconets (SOP's) is provided by a combination of FDMA and TFC's. The combination of FDMA and TFC's provides a simplified interface between the MAC and PHY.
摘要:
Systems and methods are disclosed for communicating on a pilot wire between Electric Vehicle Service Equipment (EVSE) and an Electric Vehicle (EV). The EVSE and EV exchange a Pulse Width Modulation (PWM) signal on the pilot wire to control charging operations of the EV. Data communications may also be transmitted on the pilot wire, such as between transmit and receive modems. The modems transmit communication signals either continuously, without regard to the state of the PWM signal, or only when the PWM is in an off-state. If transmitting while PWM is on, the modem needs a large coupling impedance and/or a large signal injection. To transmit only when the PWM is off, the modem may use a blocking diode in the coupling circuit or may synchronize to the pulses in the PWM signal.
摘要:
A device for communicating digital data over power lines includes a power line interface for transmitting data over at least one band of frequencies. An orthogonal frequency division multiplexing (OFDM) modulation unit generates OFDM symbols using a set of tones for the frequency band. A preamble generation unit generates preamble sequences for the frequency band by using the set of tones used by the OFDM modulation unit. The tones used by the preamble generation unit have a constant magnitude, and a set of phases obtained by quantizing to a small alphabet the phase of a set of tones obtained by taking an IFFT of a portion of a preamble used by a non-interoperable powerline access device. The device may transmit on two or more bands using a sampling frequency clock, wherein a lower band clock frequency is equal to or an integer divisor of a higher band clock frequency.