32results about How to "Improve receiver performance" patented technology

In the method of determining an airlink modulation and coding scheme, at least one link quality indicator is compensated, and a modulation and coding scheme is read from a table using the compensated link quality indicator. In one embodiment, the at least one link quality indicator includes bit error probability (BEP).

The invention discloses a semi-static resource scheduling method, which comprises the steps of: monitoring downlink channel control information DCI of a first format group format, and activating semi-static scheduling SPS according to the indication of the DCI of the first format group format; and monitoring DCI of a second format group format, releasing SPS according to the indication of the DCIof the second format group format, wherein the DCI format load size of the second format group format is smaller than that of the first format group format. Compared with the prior art, the scheduledDCI format load size after SPS activation is smaller than that of SPS activation, the power consumption of monitoring and detecting the DCI by means of UE is reduced, the downlink channel scheduling overhead of the SPS is decreased, the service time delay is reduced, and the efficiency of resource utilization is significantly improved. In addition, the invention further discloses user equipment used for semi-static resource scheduling.

A method for transmitting a multiple codeword (MCW) in a Multiple Input Multiple Output (MIMO) communication system is disclosed. A method for transmitting a multiple codeword (MCW) in a Multiple-Input Multiple-Output (MIMO) communication system includes performing a channel coding and modulation process for each codeword of the multiple codeword (MCW), multiplying the channel-coded-modulated result by a rotation matrix decided by either a spatial multiplexing rate or a layer (R), and performing a codeword permutation (CP) on the multiple codeword (MCW), performing a MIMO encoding on the multiple codeword (MCW), and transmitting the multiple codeword (MCW) via a multi-antenna.

A method and apparatus for generating and distributing satellite tracking data to a remote receiver is disclosed. The method for includes extracting from satellite-tracking data initial model parameters representing a current orbit of at least one satellite-positioning-system satellite, computing an orbit model using the initial model parameters, wherein a duration of the orbit model is longer than a duration of the satellite-tracking data, comparing, for an overlapping period of time, the orbit model to the satellite-tracking data; and adjusting the orbit model to match the satellite tracking data for the overlapping period of time so as to form an adjusted orbit model. The adjusted orbit model comprises the long-term-satellite-tracking data.

Systems and methods for communication system having improved transmitter and/or receiver performance. The invention may include systems and methods related to the use of non-superconducting and/or superconducting filters for a receiver and/or a transmitter. The invention is particularly useful in electronic communication systems that have heavy usage and requiring accurate and sharp channel filtering, for example wireless communication systems. In various embodiments, a receive filter network may include a non-superconducting filter and/or a superconducting filter. In various embodiments, a transmit filter network may include a non-superconducting filter and/or a superconducting filter. The superconducting filter(s) may be, for example, a band pass filter and/or a notch filter or band reject filter.

In a backscatter interrogator reception method, a continuous carrier signal with a frequency f_c is sent from an interrogator to a tag device over a wireless link, the tag device transmits data to the interrogator using a modulated backscatter signal, and the received modulated backscatter signal is demodulated by the interrogator to retrieve the data transmitted from the tag device. According to the present invention, the interrogator estimates the phase and the amplitude of an inband interferer signal contained in the received modulated backscatter signal, generates a cancellation signal having the opposite phase and the same amplitude as the estimation of the inband interferer signal, and combines said cancellation signal with the received backscatter signal in order to reduce the influence of the inband interferer signal. In addition, a two-stage interferer cancellation scheme is proposed.

An approach is provided for minimizing co-channel interference in a communication system is disclosed. A header of a first frame is scrambled based on a first unique word. A header of a second frame is scrambled based on a second unique word. The first frame including the corresponding scrambled header and the second frame including the corresponding scrambled header are transmitted, respectively, over adjacent co-channels of the communication system. Each of the frames further includes a payload and a pilot block. The payload and the pilot block of the first frame are scrambled based on a first scrambling sequence. The payload and the pilot block of the second frame are scrambled based on a second scrambling sequence. The above arrangement is particularly suited to a digital satellite broadcast and interactive system.

A method equalizes and decodes a received signal including a sequence of symbols. Subsequences of the signal are selected, wherein the subsequences are overlapping and time shifted. For each subsequence, statistics of the channel corresponding to a pattern in the subsequence are selected, wherein the statistics include high-order statistics. A transmitted signal corresponding to the received signal is then estimated based on the statistics.

Provided are a beam combining and hybrid beam selection method that can improve digital broadcasting reception performance by combining more than two beam output signals (beam combination type) instead of simply selecting one of beam output signals (beam selection type), or even selecting an optimal method between the beam selection type and the beam combination type, and a digital broadcasting receiving apparatus using the same. The beam selecting method includes: a) calculating SMNRs (mainpath signal to multipath signal and noise ratios) with respect to a plurality of beam output signals, formed according to directions from a plurality of antenna output signals whose phases are shifted depending on arrangement positions of array antennas, by using corresponding channel impulse responses; b) selecting a first predetermined number of beam output signals according to magnitudes of the SMNRs by comparing the calculated SMNRs with respect to the respective beam output signals; c) calculating a delay time between mainpath signals of the selected beam output signals, and generating a combined beam output signal by combining the two beam output signals by adjusting the calculated delay time; d) when the SMNR of the combined beam output signal is less than the maximal SMNR of the selected beam output signals, calculating an SDMR (mainpath signal to dominant multipath signal ratio) with respect to the respective beam output signals, and selecting a beam output signal having the greatest SDMR; and e) calculating an SMNR of the combined beam output signal using channel impulse response of the combined beam output signal, and comparing the calculated SMNR with a maximal value among the SMNRs of the selected beam output signals; and f) when the SMNR of the combined beam output signal is greater than or equal to the maximal SMNR of the selected output signals, selecting the combined beam output signal generated in step c).

A method and apparatus for generating and distributing satellite tracking data to a remote receiver is disclosed. The method for includes extracting from memory at least a portion of long-term-satellite-tracking data, generating formatted data from the at least a portion of long-term-satellite-tracking data, the formatting data being in a format supported by the remote receiver, applying security to the formatted data to prevent unauthorized access to and/or tampering with the at least a portion of long-term-satellite-tracking data; and transmitting the formatted data to the remote receiver.

A method of adapting an antenna to a transceiver system having a receiver subsystem and a transmitter subsystem comprises using an automatic tuning system to tune the antenna with respect to the receiver subsystem. The tuning results in an optimal receive signal at the receiver subsystem in response to RF energy radiated to the antenna. The tuning system may include a tuning detection element for radiating RF energy to the antenna, and a tuning element for tuning the antenna. After tuning the antenna, the method further comprises tuning a tunable matching network, coupled between an output of an RF power device of the transmitter subsystem and an input of the antenna, to facilitate an optimal power transfer amount from the RF power device to the antenna while the RF power device operates according to certain desired parameters. The desired parameters may include output power and efficiency.

A transmitter is provided. The transmitter includes: a Low Density Parity Check (LDPC) encoder configured to encode outer-encoded bits to generate an LDPC codeword including LDPC information bits and parity bits; a puncturer configured to puncture some of the parity bits included in the LDPC codeword; and a mapper configured to map the LDPC codeword except the punctured parity bits to symbols for transmission to a receiver, wherein the puncturer calculates a number of parity bits to be punctured among the parity bits included in the LDPC codeword based on a number of the outer-encoded bits, a number of the LDPC information bits, and a minimum number of parity bits to be punctured among the parity bits included in the LDPC codeword.

The present invention uses narrow-band monobit receivers after a digital filter bank to separate simultaneous signals in one channel. The invention improves the capability of wideband digital receivers.

A clock regeneration method, for generating a clock signal for being utilized by a receiver/transceiver/receiver system/transceiver system, includes: performing data/pattern detection on at least one input signal to generate recovered data; detecting at least one synchronization pattern in the input signal according to a synchronization pattern rule, and generating a synchronization signal corresponding to the synchronization pattern; and performing frequency-locking on the synchronization signal to generate the clock signal. More particularly, the step of detecting the at least one synchronization pattern in the input signal according to the synchronization pattern rule further comprises: detecting the at least one synchronization pattern by performing synchronization pattern detection on the recovered data. An associated reference-less receiver and an associated crystal-less system are also provided.

Methods and apparatus are provided for transmitting data in a broadcasting system. Input data is encoded by an encoder. A first demultiplexer generates first transmission symbols using the encoded data. The first transmission symbols are modulated, and the modulated first transmission symbols are transmitted. A second demultiplexer generates second transmission symbols using at least a portion of the encoded data. The second transmission symbols are modulated and the modulated second transmission symbols are transmitted.

The present invention is directed to a receiver for a wire-free communication system for reception of a received signal which is modulated using a digital modulation method having a first frequency conversion device for production of a frequency-converted received signal by conversion of the received signal to an intermediate frequency. The receiver further includes a pre-filter for production of a filtered received signal from the frequency-converted received signal such that the received signal is band-limited, and an analogue/digital converter for production of a binary received signal from the filtered received signal by comparison of the filtered received signal with a level threshold. In addition, the receiver includes a phase reconstruction device for production of a phase-reconstructed received signal by reproduction of the phase of the received signal from the time intervals between zero crossings of the binary received signal, and a mapping device for production of a bit sequence by mapping symbols from the phase-reconstructed received signal onto this bit sequence using the digital modulation method.

The invention provides improved suppression of co-channel interference (CCI) in a wireless cellular communications system where at least two base stations use the same transmit frequency. The method according to the invention uses the difference in synchronization times between the home signal and the CCI signal to suppress the CCI signal. The method uses a modified known method of estimating time of arrival (TOA) to estimate sync positions for the CCI signal. This enables the use of interference cancelling methods in communications systems using un-synchronized base stations. Receiver performance is improved, which in turn improves data throughput and received speech quality, since interfering signals from base stations using the same frequency can be suppressed.

The embodiment of the invention provides a signal determination method and device, electronic equipment and a storage medium. The method comprises the steps of acquiring a sample signal and a currentreceiving signal; determining a joint probability density function of the sample signal and the current received signal with respect to each parameter to be estimated; determining an expression corresponding to the parameter to be estimated when the joint probability density function obtains a maximum value through a maximum likelihood estimation algorithm; calculating doppler frequency offset andcode delay through a Gauss Newton method, and obtaining a target value of the Doppler frequency offset, a target value of the code delay, a target value of a carrier phase and a target value of a signal amplitude according to an expression corresponding to a parameter to be estimated when a calculation result of the Doppler frequency offset and the code delay meets preset conditions, wherein thetarget value of the Doppler frequency offset, the target value of the code delay, the target value of the carrier phase and the target value of the signal amplitude represent the current received signal. According to the invention, stable tracking of a signal with a small duty ratio is realized.

The time-varying least-mean-fourth-based channel equalization method is an automated procedure that provides an adaptive equalizer in a CDMA receiver. Equalizer filter coefficients are estimated using a least-mean-fourth (LMF) error calculation based on a training set of symbols sent by the transmitter. When the LMF error calculation is combined with a power-of-two quantization (PTQ) process, superior receiver performance is achieved in a time-varying CDMA channel operating in non-Gaussian noise environments.

A method and apparatus for creating and distributing satellite tracking data in a compact format to a remote receiver. At least a portion of the satellite tracking data is extracted from memory and is formatted into a compact format. The compact formatted data is transmitted to the remote receiver via a distribution network. Once this data is received at the remote receiver it is reformatted into a format prescribed by the remote receiver

A channel equalizer includes an equalizer filter for correcting an error upon receipt of a signal transmitted by a sending end, a DD slicer for calculating a first error upon receipt of the corrected signal from the equalizer filter, a Sato slicer for calculating a second error upon receipt of the corrected signal from the equalizer filter, and a DD error size calculation unit for taking the absolute value of the real part and imaginary part of the first error calculated from the DD slicer and summing these absolute values.

The invention provides a DVB-RCS2 RL three-turbine iterative receiver and a receiving method, which are characterized in that on the basis of a Mesh RCST RL LM receiver, the assumed posterior probability log-likelihood ratio information of an effective load symbol output by iteration of a DVB-RCS2 RL LM Turbo code decoder is fully utilized, and three turbine iterative operations of iterative synchronization, iterative equalization and iterative noise interference cancellation are executed in parallel. According to the method, carrier frequency deviation, carrier phase deviation, timing deviation and amplitude change are eliminated through iterative synchronization and iterative channel estimation, iterative equalization is achieved, and the influence of adjacent satellite interference, ACI and IMI is relieved through the iterative noise interference estimation and offset technology. In addition, the influence of CCI can be reduced by using an iterative noise interference estimation and cancellation technology, so that a high-efficiency multiple access scheme in which a plurality of users transmit at the same frequency or time slot is allowed to be adopted.

A transmitter is provided. The transmitter includes at least one processor configured to implement: a Low Density Parity Check (LDPC) encoder which encodes input bits to generate an LDPC codeword including the input bits and parity bits; a puncturer which calculates a number of bits to be punctured in the parity bits and punctures the parity bits based on the calculated number of bits; and a repeater which selects at least a part of bits of the LDPC codeword based on a repetition pattern, and repeats the selected bits after the parity bits, wherein the repetition pattern is a pattern for selecting at least one bit group including the selected bits among a plurality of bit groups configuring the LDPC codeword.

The invention relates to a method of compensating the Doppler effect for a mobile receiver. This method consists in producing a phase- locked loop based on the signal to be demodulated to correct the frequency control of the tuner element and thus the drift due to the Doppler effect. The invention also relates to a receiver implementing this method.

The invention relates to a method for increasing the capacity of a wireless communications system comprising at least two users U₁ and U₂ communicating by means of at least one frequency band F₁, F₂ wherein the stream of information s₁(t) of the first user U₁ and the stream of information s₂(t) of the second user U₂ flow in at least one same frequency band.