摘要:
The present invention is an improved system and method for transmitting and receiving digital information over mobile communication channels. The present invention includes an enhanced channel estimator (34) which iteratively estimates channel amplitude and phase distortion from received pilot and data signal information at various time instants. The iterative channel estimation scheme of the present invention provides increased performance of the transceiver system which allows for efficiencies such as transmission of a minimal amount of pilot information and reduction in the transmitted power.
摘要:
A circuit is designed with a correction circuit (350) coupled to receive a first estimate signal (&agr;j1), a second estimate signal (&agr;j2), and a plurality of input signals from an external source along plural signal paths. The plurality of input signals includes a first and a second input signal (Rj1, Rj2) The correction circuit produces a first symbol estimate in response to the first and second estimate signals and the first and second input signals. The correction circuit produces a second symbol estimate in response to the first and second estimate signals and the first and second input signals. A combining circuit is coupled to receive a plurality of first symbol estimates including the first symbol estimate and a plurality of second symbol estimates including the second symbol estimate. The combining circuit produces a first symbol signal ({tilde over (S)}1) in response to the plurality of first symbol estimates and a second symbol signal ({tilde over (S)}2) in response to the plurality of second symbol estimates. A synchronization circuit (408) is coupled to receive the first and second symbol signals (400-406) and a first known symbol and a second known symbol (410-416). The synchronization circuit produces a synchronization signal (418) in response to an approximate match between the first symbol signal and the first known symbol and between the second symbol signal and the second known symbol.
摘要:
A circuit is designed with a measurement circuit (432). The measurement circuit is coupled to receive a first input signal (903) from a first antenna (128) of a transmitter and coupled to receive a second input signal (913) from a second antenna (130) of the transmitter. Each of the first and second signals is transmitted at a first time. The measurement circuit produces an output signal corresponding to a magnitude of the first and second signals. A control circuit (430) is coupled to receive the output signal and a reference signal. The control circuit is arranged to produce a control signal at a second time in response to a comparison of the output signal and the reference signal.
摘要:
A circuit for detecting a serial signal comprises a first circuit coupled to receive the serial signal during a predetermined plurality of time periods of substantially equal duration. The first circuit is coupled to receive a first code. The first circuit is arranged to compare a part of the serial signal corresponding to each time period of the plurality of timer periods to the first code, thereby producing a match signal. The first circuit accumulates the match signal from each of the each time period of the plurality of time periods.
摘要:
Embodiments of the invention provide a system and method for chip to chip communications in electronic circuits. A router or switch receives data packets at input port ASICs. A routing table on the input port ASIC or on a routing ASIC is used to identify a destination port ASIC based upon header information in the data packet. The data packet is transmitted from the input port ASIC to the destination port ASIC using millimeter wave signals that are transmitted across a waveguide or a wireless interface.
摘要:
The present invention provides a time-orthogonal preamble supplement generator for use with a multiple-input, multiple-output (MIMO) transmitter employing N transmit antennas, where N is at least two. In one embodiment, the time-orthogonal preamble supplement generator includes an initial preamble supplement encoder configured to provide a preamble supplement to each of the N transmit antennas during an initial time interval. The time-orthogonal preamble supplement generator also includes a subsequent preamble supplement encoder coupled to the initial preamble supplement encoder and configured to provide the preamble supplement or a negation thereof to the N transmit antennas during (N−1) subsequent time intervals.
摘要:
A wireless transmitter (TX1). The transmitter comprises circuitry for providing a plurality of control (CONTROL) bits and circuitry for providing a plurality of user (USER) bits. The transmitter also comprises circuitry for modulating (16) the plurality of control bits and the plurality of user bits into a stream of complex symbols and circuitry (18) for converting the stream of complex symbols into a parallel plurality of complex symbol streams. The transmitter also comprises circuitry (20) for performing an inverse fast Fourier transform on the parallel plurality of complex symbol streams to form a parallel plurality of OFDM symbols and circuitry (22) for converting the parallel plurality of OFDM symbols into a serial stream of OFDM symbols. Each OFDM symbol in the serial stream of OFDM symbols comprises a plurality of data points, and selected (SF2.x) OFDM symbols in the serial stream of OFDM symbols carry modulation information (AMOD). The modulation information in one or more of the selected OFDM symbols comprises a plurality of modulation groups, and the plurality of modulation groups comprises a number of modulation parameters that describe modulation of a corresponding set of data points in a subsequent OFDM symbol in the serial stream of OFDM symbols.
摘要:
A method of estimating a channel length (304) in a wireless receiver is disclosed. The receiver receives a signal (122) from a remote transmitter. The receiver selects a plurality (K) of different candidate channel lengths and determines a respective criterion value (402) of the signal for each of the plurality of different candidate channel lengths. The receiver selects a channel length (410) from the plurality of different candidate channel lengths in response to the respective criterion value (404).
摘要:
A wireless communication system. The system comprises transmitter circuitry (BST1), the transmitter circuitry comprising encoder circuitry (50) for transmitting a plurality of frames (FR). Each of the plurality of frames comprises a primary synchronization code (PCS) and a secondary synchronization code (SSC). The encoder circuitry comprises of circuitry (501) for providing the primary synchronization code in response to a first sequence (32). The encoder circuitry further comprises circuitry (502) for providing the secondary synchronization code in response to a second sequence (54) and a third sequence (56). The second sequence is selected from a plurality of sequences. Each of the plurality of sequences is orthogonal with respect to all other sequences in the plurality of sequences. The third sequence comprises a subset of bits from the first sequence.
摘要:
An apparatus (100) for computing the absolute value of a complex number includes separate squaring units (110, 115) for the real and imaginary parts. A square root unit (130) extracts the square root of the sum (120) of these squares, which is absolute value of the complex number. Each squaring unit includes one unsigned multipliers for respective least significant and two signed multipliers for respective most significant bits and a cross term. The products are aligned by shifting and summed. The square root unit employs identical processing elements, each considering two bits of the input and forming one root bit and a remainder. Each processing element compares two intermediate test variables, and selects a “1” or “0” for the root bit and the next remainder based upon this comparison. A chain of processing elements enables computation of the root to the desired precision. Alternatively, the same processing elements may be used in a recirculating manner.