139 results about "Symbol error rate" patented technology

Disclosed is an apparatus and method for adaptively allocating transmission power for beamforming combined with orthogonal space-time block codes (OSTBC) in a distributed wireless communication system, the apparatus comprising: a plurality of sub-arrays for beamforming, which are geographically distributed and each of which comprises a plurality of distributed antennas placed in random groups; and a central processing unit for identifying performances of subsets by applying a predetermined power allocation scheme according to subsets which can be obtained by combining the sub-arrays, by means of a Nakagami fading parameter and information about large-scale fading of each of the sub-arrays, fed back from a receiving party, for determining a subset having a best performance as an optimal subset according to the identified performances, and for performing power allocation based on the subset set as the optimal subset.

A receiver may be operable to receive a QAM-based, inter-symbol correlated (ISC) signal at a signal-to-noise ratio of between 29 dB and 31 dB and process the QAM-based, ISC signal to output estimated symbols at a symbol error rate of between 2×10⁻¹ and 1×10⁻³. The QAM-based, ISC signal may be a partial response signal generated by passing a first signal through a partial response pulse shaping filter. The partial response pulse shaping filter may provide greater capacity than a capacity achieved by passing the first signal through a root-raised-cosine-based pulse shaping filter. The receiver may comprises an input filter, and the processing of the QAM-based, ISC signal may comprises filtering the QAM-based, ISC signal via a filter configured to achieve a desired total partial response in combination with the partial response pulse shaping filter.

Disclosed is a device for allocating transmission power using a symbol error rate (SER) for orthogonal space-time block codes (OSTBC) in a wireless communication system. The device includes: a plurality of antennas, which are distributed geographically and independently linked to a central processing unit; a receiver to select an optimum subset of the SER performance, using a preset power allocation to each of available antenna subset combinations, and sending the selected subset to a transmitter; and a central processing unit to allocate power by applying an OSTBC symbol having a unit average power to the optimum subset from the receiver.

What is disclosed is a system and method for encoding and decoding data in a color barcode pattern using dot orientation and color separability. The spectral (wavelength) characteristics of the CMY colorants, commonly used in digital printing, and those of RGB sensors are exploited to achieve high capacity data embedding rates in color barcodes. The present method embeds independent data in two different printer colorant channels using dot orientation modulation. In the print end, dots of two colorants occupy the same spatial region. At the detector end, by using the complementary sensor channels to estimate the colorant channels, data is recovered in each colorant channel. The method approximately doubles the capacity of encoding methods based upon a single colorant channel and enables embedding rates which match or exceed that of other hardcopy barcodes known in the arts. The method is robust against inter-separation misregistration with a small symbol error rate.

Techniques to adjust the setpoint of a power control loop in a wireless communication system. The setpoint may be adjusted based on frame status indicative of erased/good decoded frames, one or more (typically soft) metrics indicative of the confidence in the decoded results, power surplus/deficit indicative of the difference between the received signal quality and the setpoint, setpoint surplus/deficit indicative of the difference between the setpoint and a threshold E_b/N_t needed for the desired level of performance, or a combination thereof. The metrics may include re-encoded symbol error rate, re-encoded power metric, modified Yamamoto metric, minimum or average LLR among decoded bits, number of decoding iterations, and possibly others. The setpoint may be adjusted in different manners and/or by different amounts depending on the above-noted factors. The techniques may be employed for forward and/or reverse links in CDMA systems.

Methods, apparatus, and systems for preventing false packet acceptance in high-speed links. Under one aspect, correctable symbol errors are detected, and determination is made to whether a symbol error rate or ratio (SER) exceeds an SER threshold. In response to detection of such a condition, the link is disconnected or temporarily paused. The value for the SER threshold is determined using a statistical analysis of various link parameters to meet desired performance levels, such as a mean time to false packet acceptance (MTTFPA) of >approximately 15 billion years while providing a mean time to disconnect of >100 years.

A Multi Input Multi Output (MIMO) Wireless Communication Reception Method and Apparatus are proposed whereby in a 2-way wireless communication system with scattering propagation channels, where several data sub-streams are simultaneously transmitted from a transmitting side to a receiving side, and where no channel information is necessarily available at the transmitting side, excellent Symbol Error Rate performance is a achieved, in some cases quasi-optimal, at a complexity scaling almost quadratically with the number of transmitted sub-streams and independent of the constellation order.

In one embodiment, a method and apparatus increases a bit load of a multicarrier system comprising a channel having a plurality of subchannels. A bit load is determined for at least one subchannel based on a target symbol error rate ε_S a maximum number of symbol errors that can be corrected t, a number of symbols in an information field K, and a maximum number of transmissions k, and a number of bits per subchannel. The maximum number of symbol errors t, the number of symbols in the information field K and the maximum number of transmissions k, is selected such that a net coding gain is increased. In another embodiment, a method determines data flow for a channel having a plurality of subchannels in a multi-carrier system.

The invention belongs to the wireless communication signal detection technical field and relates to a block compressive sensing non-orthogonal multiple-address system multiuser detection method. The invention provides a sparseness adaptive detection method which can recombine structured sparseness into block sparseness. According to the block compressive sensing non-orthogonal multiple-address system multiuser detection method of the invention, a block sparseness-adaptive sub-space tracking algorithm is adopted for recombined block sparseness signals; according to the algorithm, a noise power setting threshold is utilized to realize the adaptive evaluation of the sparseness of users, and SER (Symbol Error Rate) performance is improved greatly compared with that of the prior art under a condition that the a priori information of sparseness degree is not required; and a simulation result indicates that the performance of the algorithm can reach an optimal theoretical value after a signal-to-noise ratio is increased to a certain extent.

An apparatus for detecting a frame transmission period in a CDMA mobile communication system supporting a discontinuous transmission mode. A first frame detector performs primary frame detection by calculating a signal-to-interference ratio (SIR) using traffic symbol energy, pilot symbol energy and noise energy measured for a predetermined time period, and comparing the SIR with a predetermined frame detection threshold value. A decoder calculates a symbol error rate (SER) by decoding symbols received for the predetermined time period. A second frame detector selects an SER threshold value according to frame detection information from the first frame detector, and compares the selected SER threshold value with the SER to determine whether a frame has been transmitted.

A method and apparatus determines an uncoded bit error rate p_b based on a target symbol error rate ε_s. The uncoded bit error rate p_b is determined based on a weighted series expansion of the target symbol error rate ε_s, comprising weights W that are a function of a maximum number of symbol errors that can be corrected t and a number of symbols in an information field K. The maximum number of symbol errors t and the number of symbols in the information field K is selected such that the uncoded bit error rate p_b that produces a symbol error rate that is less than or equal to the target symbol error rate ε_s is largest.

Data communication includes an estimate of packet error rate that is useful, for example, when there is insufficient data transmission to provide a direct measurement of packet error rate. At least one pilot channel output provides a basis to determine an estimated packet error rate. One example includes using a pilot channel ratio of an energy-per-chip to a noise spectrum density. Another example includes using a pilot symbol error rate from the pilot channel as the basis for determining the traffic channel packet error rate.

The invention relates to a precoding design method of a maximized minimum signal to noise ratio in a large-scale MIMO (multiple input multiple output) system. At first, according to an instant receiving signal to noise ratio of a sub-channel in every radio frequency port of a ZF (zero frequency) receiver used by a base station terminal in an uplink, a mean receiving signal to noise ratio is obtained by using a multivariate statistics method; the sub-channel is optimized on the basis of the maximized minimum mean receiving signal to noise ratio rule; according to the independence of distribution type MIMO ports, the optimization of the mean receiving signal to noise ratio is decomposed to be a precoding matrix design under the limit of independent power in ports and the total power restraint power distribution optimization design between ports; finally, the optimal precoding matrix is obtained. The precoding design method of the maximized minimum signal to noise ratio in the large-scale MIMO obtains the optimal porecoding matrix by bysing the statistical information of a channel only, and has low system feedback cost; meanwhile, in comparison to the traditional power distribution method, the method can obviously improve the mean symbol error rate performance of a system, and thereby promoting the feasibility of the method in actual application.

The invention discloses an interference avoidance and secure transmission method based on signal alignment for use in a collaborative device-to-device (D2D) system. The method comprises the following steps that: a base station (SB), a user D<1>, a user D<2> and a cellular user (CU) transmit signal constellation points out after signal constellation rotation firstly during information transmission; and every collaborative transmission between a D2D subsystem and a cellular subsystem consists of two stages, wherein at a first stage, the BS, the CU and the user D<2> transmit respective signals to the user D<1> respectively; and at a second stage, the user D<1> forwards a composite signal consisting of the signal transmitted by the BS and the signal transmitted by the CU to realize bilateral information transmission between the CU and the BS, and meanwhile, the user D<1> transmits a signal needing to be transmitted of the user D<1> to the user D<2>. Through adoption of the method, the security of the collaborative D2D system can be enhanced effectively, and the symbol error rate of the collaborative D2D system is lowered.

The invention discloses transmission mode selection method and device and user equipment. The method includes: acquiring channel matrix of subframes in an adaptive transmission cycle by channel estimation; calculating average channel capacity and average symbol error rate of each component carrier in the subframes in different transmission modes by the acquired channel matrix; and selecting a transmission mode combination, meeting the requirements for system transmission rate and system symbol error rate, for each component carrier according to the calculated average channel capacity and average symbol error rate. On the premise of random channels, the average channel capacity and average symbol error rate of each component carrier are traversed and calculated, the system requirements for transmission rate and symbol error rate are considered comprehensively, and accordingly user throughput is effectively increased with accurate transmission of user data guaranteed, and spectral efficiency of the user equipment is maximized.

An equalization method and device for equalizing the received vestigial sideband (VSB) signal, utilizes segment-sync symbols, Sato directions, erasure slicers, and variable step-sizes. In addition to stop-and-go (SAG) mode, the directions of Sato errors can also be used for speed up the convergence of tap weights of the equalizer. Erasure slicers can mitigate the effect of decision errors as they are passed through the feedback filter. In time-variant environments, variable step-sizes help the equalizer tracking the variations of the channels; in time-invariant environments, variable step-sizes help ease the fluctuations of the steady-state equalizer tap weights, and therefore yield smaller mean-squared-error and better symbol error rate (SER).

A multicarrier transmitting apparatus capable of improving the data symbol error rate characteristic to improve the reception quality. In this apparatus, a replacement position deciding part (141) decides, based on a number of replacements notified of by a scheduler (110), which one of a plurality of data symbols should replaced by a second pilot. Herein, a restricted condition, which is ‘RF after replacement is equal to or greater than RF before replacement minus one’, is satisfied. A replacing part (142) replaces, in accordance with the replacement position outputted from the replacement position deciding part (141), a part of the data symbols included in a repetition signal by a second pilot symbol, and outputs the resultant replaced signal to an IFFT part (105).