232 results about "Frame error rate" patented technology

A method for engineering management and planning for the design of a wireless communications network in three-dimensions (3-D) combines computerized organization, database fusion, and radio frequency (RF) site-specific planning models. The method enables a designer to keep track of wireless system performance throughout the process of pre-bid design, installation and maintenance of a wireless system. Using a database of information that defines the desired environment, predictions of antenna coverage, system coverage and interference, and other wireless system performance criteria, such as frame error rate and network throughput, can be made. Watch points are created to ensure, in real time, that any modifications to the design of the wireless system do not degrade the performance of the system with respect to the watch point locations.

The invention discloses a polarization code and multi-bit even parity check code cascaded error correction coding method. The method comprises the steps: a transmitting end encoder utilizes a multi-bit even parity check code as an outer code, and utilizes a polarization code as an inner code; a receiving end decoder decodes by utilizing a modified successive cancellation list (SCL) decoding algorithm. On the aspect of error correction performance, comparing with the prior art utilizing middle-short code length non-cascaded polarization codes of the SCL decoding algorithm, the polarization code and multi-bit even parity check code cascaded error correction coding method has the advantages that frame error rate performance of a system can be remarkably improved, and a maximum likelihood bound (ML Bound), which cannot be broken through by the SCL decoding algorithm, can be remarkably broken through. On the aspect of engineering realization, according to the polarization code and multi-bit even parity check code cascaded error correction coding method, the outer code utilizes the multi-bit even parity check code, which is simple to code; the modified SCL decoding algorithm is utilized to decode, bit decision and even parity check are combined to be carried out in a decoding process, and compared with the original SCL decoding algorithm, the method provided by the invention does not increase the decoding complexity, and facilitates the engineering realization.

Data rate determination is provided in a system where the available power fraction and available Walsh codes in each active leg are dynamically changing over time. This method adapts the rate (modulation and coding) based on the combined resource (power & code space) levels seen at each cell. The method results in maximization of the rate supportable by each cell given their resource constrained situation while meeting the constraints of target packet or frame error rate and orthogonality. Furthermore, improved fast cell selection by the mobile results due to this approach that is based on knowledge of combined resource (power & code space) levels across the cells in the active set.

The invention discloses a method and device for rate matching of Polar codes. The method comprises the steps of: performing Polar code encoding on an information bit sequence with a K-bit length, and generating an encoding bit sequence with an M-bit length; selecting Nmin bits from the encoding bit sequence as the first bit to Nmin-th bit of a bit sequence to be transmitted during a hybrid automatic repeat request (HARQ) process; and determining each bit of (Nmin+1)th bit to Nmax-th bit of the bit sequence to be transmitted from the information bit sequence and the encoding bit sequence, wherein each bit of the (Nmin+1)th bit to the Nmax-th bit of the bit sequence to be transmitted is determined according to a frame error rate of the bit sequence to be transmitted when each bit is added into the bit sequence to be transmitted. By adopting the method of the embodiment of the invention, HARQ transmission based on Polar code encoding can be achieved, and better encoding gain can be obtained.

A method and apparatus for controlling a signal transmission power. The method of the present invention includes the steps of demodulating a received signal to produce a demodulated signal and distorting the demodulated signal to produce a distorted demodulated signal. The demodulated signal can be distorted by, for example, adding noise. A signal quality measurement, such as signal-to-noise ratio, is then determined based on the distorted demodulated signal rather than the demodulated signal. An adjustment in the transmission power is then requested based on the signal quality measurement of the distorted demodulated signal.

This invention relates to a transmission power control method and transmission power control apparatus in a mobile communication system. The reception quality of a signal (31, 32a, 32b, 41, or 42) transmitted from another mobile station (51 or 52) or base station (21 or 22) is compared with a predetermined control target value such as a signal-to-interference ratio. The comparison result is used for transmission power control on a remote station. If a frame error is detected in a transmitted signal, the control target value is increased by SIRinc. If no frame error is detected, the control target value is decreased by SIRdec. As SIRdec, the product of a target value of a frame error rate and SIRinc is set. With this operation, when a propagation environment such as multibus or moving speed changes, the control target value for transmission power control is changed within a short period of time, and channel quality is maintained constant, thus realizing desired channel quality.

A method and apparatus for calculating a routing metric for a wireless network including retrieving configured system parameters, selecting a form of a first weight factor based on channel load/utilization and parameters of the first weight factor, selecting a form of a second weight factor based on frame/packet error rate and parameters of the second weight factor, retrieving estimated link bit rate, measuring a channel/link busy time, estimating a channel/link load, estimating a packet/frame error rate of the link and calculating the metric are described. A method and system for determining a route/path between two nodes of a wireless network including calculating a weighted radio and load aware metric by each node in the wireless network, storing the metric and using the metric to select the route/path for communication between two nodes of the wireless network based on a sum of the metrics calculated by each node of the wireless network are also described.

For each access point in a first network of a first type, a mobile device identifies a frame error rate of communications. The frame error rate is measured while simultaneously communicating with a second network of a second type. The mobile device stores the frame error rate in association with an access point identifier of the access point. Upon encountering, the first network again, the mobile device prioritizes the selection of an access point based on a ranking of the access points according to their associated frame error rates from lowest to highest. Further, the mobile device may use adjusted hysteresis parameters for making a handover decision in order to reduce a “ping-pong” selection between access points. Additionally or alternatively, the mobile device may select or suggest a channel of the access point based on a signal strength of signals from the second network.

The invention provides a wireless Mesh intelligent power grid routing mechanism NQA-LB with QoS perceiving and loading balancing. The mechanism comprises four steps: firstly differentiating intelligent power grid service flows with different QoS requirements through an EDCA mechanism, and calculating the frame error rate of different service flows according to the data packet collision rate of the EDCA mechanism; secondly, calculating data packet queuing delay with different priorities of the queue length of forwarding node cache and the successful transmission probability of data packets; then designing the routing metric of QoS perceiving and loading balancing by comprehensively considering the data frame error rate and queuing delay of different service flows, and selecting an optimal path with less load for the service flow with different QoS demands; finally dynamically adjusting the data packet priority on an MAC layer according to network total loading and loading conditions of all priority service flows. The mechanism can more accurately perceive the link quality of the MAC layer, guarantees the QoS demands of different service flows of a power grid, further increases the data packet delivery rate and average throughput capacity, and reduces the end-to-end delay of all service flows.

A system is implemented on a wireless network for adjusting a forward link power control parameter based on forward link feedback. A wireless unit is in communication with several base stations during soft handoff, and provides feedback relating to forward link quality, e.g., forward link pilot signal strength or traffic channel frame error rate. The feedback is compared to a comparison or reference point (such as target frame error rate, or a maximum pilot signal strength in the active set) chosen for gauging the quality or nature of the feedback for power control purposes. Based on this comparison, a power control parameter of one or more of the base stations may be adjusted upwards or downward. The power control parameter may be a forward link reference transmit power level “P_ref” used to control base station power transmission levels in the presence of power control bit errors.

Methods of early-termination and output selection for iterative decoders are disclosed. A hybrid early-termination method combines the output-comparison-based method with the parity-check-based method. The hybrid approach is far more superior in termination reliability in either of the two individual approaches, without their disadvantages. The hybrid termination method effectively and reliably terminates the iterative decoding process, cutting the majority of the computational load while eliminating the degradation in the bit error rate (BER) and frame-error-rate (FER) performance due to incorrectly terminated frames. An output selection procedure chooses the best possible decoded frame among those from all iterations if the iterative decoding process cannot be early-terminated during the decoding of a received frame and if the iterative decoder has reached the maximum number of iterations, thereby eliminating the iteration abnormality that is inherent in the iterative decoding approach, and improving the BER performance of the standard iterative decoders.

An apparatus and method of constructing a universal polar code is provided. The apparatus includes a first function block configured to polarize and degrade a class of channels W_j to determine a probability of error P_e,j of each bit-channel of W_j, wherein jε{1, 2, . . . , s}, in accordance with a bit-channel index i; a second function block configured to determine a probability of error P_e⁽ⁱ⁾ for the universal polar code for each bit-channel index i; a third function block configured to sort the P_e⁽ⁱ⁾; and a fourth function block configured to determine a largest number k of bit-channels such that a sum of corresponding k bit-channel error probabilities P_e⁽ⁱ⁾ is less than or equal to a target frame error rate P_t for the universal polar code, wherein the indices corresponding to the k smallest P_e⁽ⁱ⁾ are good bit-channels for the universal polar code.

The invention discloses a concatenated error correction coding and decoding method based on a polarization code and belongs to the technical field of error correction coding and decoding. The method comprises steps that at the transmitting end, an outer encoder first encodes an information sequence into which the fixed bit is inserted, and obtains the outer code word; the outer code word is used as an input sequence of the polarization code encoder, the polarization code is encoded, and the concatenated code word is obtained; and a receiver decoder uses a combined SCL decoding algorithm to perform decoding. Meanwhile, the invention also discloses a concatenated error correction coding and decoding system based on the polarization code. The frame error rate performance of the coding method provided by the technical scheme of the invention significantly exceeds the performance of the frame error rate of the polarization code under the SCL decoding algorithm or the CRC-aided SCL decoding algorithm; and the outer encoder is extremely low in storage complexity and operation complexity, and the coding is simple. The decoding complexity of the combined SCL decoding algorithm adopted by the invention is not increased compared with the original SCL decoding algorithm or the CRC-aided SCL decoding algorithm, so that the engineering realization is benefited.

The present invention discloses a polar code-repeat code cascade error correction coding method. At a transmit end, the repeat code is used as an outside code, and the polar code is used as an inside code; and a decoder of a receive end uses a correction successive cancellation list (SCL) decoding algorithm to decode. In terms of correction performance, the frame error rate performance of the coding method provided in the present invention is highly stronger than the polar code frame error rate performance of the SCL decoding algorithm or a cyclical redundancy check (CRC)-aided SCL decoding algorithm, and the frame error rate far exceeds the unsurpassed maximum likelihood limit of the SCL decoding algorithm. In terms of engineering implementation, the outside code uses the repeat code, the storage complexity of the outside code coder is very low, the coding is simple, the correction SCL decoding algorithm is adopted for decoding, bit determining of the inside code-polar code and bit determining of the outside code-repeat code are performed jointly, and the decoding complexity is not increased compared with that of the original SCL decoding algorithm and the CRC-aided SCL decoding algorithm, so that the engineering is easy to implement.

The embodiment of the invention provides a reception/transmission combining method. The method comprises the following steps: receiving and caching data symbols that are transmitted at least twice by a transmitting terminal relative to a group of data, wherein the data symbols are acquired after modulating the data by the transmitting terminal; and combining the received data symbols and subjecting to channel equalization, and then obtaining the combined received data by means of demodulation and decoding. The embodiment of the invention also provides a reception/transmission combining methodsystem and a reception/transmission combining device. The reception/transmission combining method demodulates and decodes the received data symbols that are transmitted at least twice after channel equalization, achieves the effect of symbol-level reception/transmission combination of the data, effectively improves the system performance, reduces the frame error rate and the bit error rate, and increases the channel capacity and the spectrum utilization rate of the system.

A sub-access point (AP), system, and method for adjusting a power level of a transmission signal, and more particularly, in which the power level of a transmission signal output from the sub-AP is adjusted based on received signal strength indicator (RSSI) readings and frame error rate (FER) of a main AP, thereby eliminating shadow areas and minimizing interference between the main AP and the sub-AP. The sub-AP includes a reception unit which receives a beacon frame and a data frame from a main AP, a RSSI checking unit which checks an RSSI of the main AP, a FER checking unit which checks an FER, and a control unit which determines a power level at which a transmission signal is to be transmitted based on the identified RSSI and the identified FER and causes a transmission signal to be output at the determined power level.

An Forward Error Correction (FEC) apparatus and method for reducing Bit error rates (BER) and Frame Error Rates (FER) using turbo decoding in a digital communication system. In a constituent decoder for decoding a turbo code, a first adder calculates the LLR of a received code symbol by calculating the difference between the probability of the code symbol being 1 and that of the code symbol being 0 at an arbitrary state of a turbo decoding trellis. A second adder adds the transmission information and a priori information of the code symbol. A third adder calculates the difference between the outputs of the first and second adders as extrinsic information. A first multiplier multiplies the output of the third adder by a predetermined weighting factor as a feedback gain. A correction value calculator calculates a correction value using the difference between the best metric and the second best metric of the code symbol. A fourth adder adds the correction value to the output of the first multiplier.

The invention discloses a polarization code belief propagation list decoding method based on bit flipping. Code words used in the method are cascade codes formed by CRC codes and polarization codes. According to the method provided by the invention, under the condition that the BPL decoding result does not pass the CRC check, a decoding result in a BPL decoding method is analyzed, a Flip Bits Set (FBS) is constructed, and information bits, located in the FBS, of the polarization codes are flipped (bit flipping is achieved by setting the prior log-likelihood ratio of flipped bits to be infinite). Errors in part of BPL decoders can be corrected, and then the bit error rate and the frame error rate performance of the BPL decoding method are improved.

A method for efficient power control in a (CDMA based) fixed wireless system. The method comprises the steps of (1) monitoring a transmission link of the fixed wireless system for an occurrence of a fade, (2) recording a number of power increases to the transmission link due to said fade, and (3) reducing the power to an appropriate level when said fade is over. The adjusting step includes the steps of determining an appropriate power-down step size, which results in saving power, wherein the step size is influenced by a frame error rate (FER) and selected to maintain a desired FER, and dynamically decreasing the power by the appropriate power-down step size, thereby conserving power and increasing system capacity.

A method increases spectral efficiency in a communication system. The communication system includes at least one mobile station and is capable of transmitting messages encoded according to a plurality of available modulation coding schemes (“MCSs”). Each available MCS includes a modulation scheme and an effective coding rate. The MCSs are indexed according to increasing complexity. A signal-to-interference ratio (“SINR”) is determined which is sufficient to satisfy a predetermined frame error rate (“FER”). A first MCS and a corresponding amount of transmissions needed to satisfy the predetermined FER at the SINR using the first MCS are determined. The first MCS has a higher effective coding rate than a second MCS. The second MCS sufficiently satisfies the predetermined FER at the SINR in a single transmission. A message encoded according to the first MCS is transmitted through the communication system using hybrid automatic repeat request (“HARQ”)

A method is provided to accurately predict the probability of successfully recovering frames of (coded) information received over a wireless link, without having to decode the frame. This method, which consists of three steps, requires only limited information about the received signals and the forward error correction code and retransmission scheme being used. First, the signal to noise ratio (SNR) of each of the received signals is measured, where the average SNR is determined for multiple segments that together constitute the frame. Next, an algorithm is employed that takes these SNR values as inputs and determines the so-called effective SNR. The algorithm translates the measured SNR values using an appropriate convex metric, and subsequently combines the resulting values, thereby factoring in the effects of fading, multi-path, and other signal degradations. In the third stage, the effective SNR is used to determine the frame error rate by using a look-up table of a single reference curve that specifies the frame error rate of the actual error control code over an additive white Gaussian noise channel. This suffices to accurately predict the performance of a wide range of mobile communication channels. This method can be applied to a variety of retransmission strategies, including hybrid automatic-repeat request (ARQ) and incremental redundancy (IR) and combinations of these two strategies.