461 results about "Modulation order" patented technology

Disclosed is an apparatus for transmitting a bit-interleaved coded modulation (BICM) signal in an orthogonal frequency division multiplexing (OFDM) system. A serial-to-parallel (S/P) converter generates bit streams using coded bits according to the number of transmission antennas and a modulation order of a predetermined modulation scheme. An interleaver applies at least one offset to the bit streams and performs interleaving on the offset-applied bit streams. A combiner combines the interleaved bit streams according to the number of transmission antennas.

An apparatus and method for determining a modulation order of packet data to be transmitted through a subcarrier in a transmission apparatus. In the apparatus and method, transmitter physical channels encode and modulate data to transmit the user data with OFDM symbols. A controller outputs packet data to the transmitter physical channels, and determines the number of transmission slots, the number of OFDM symbols, the number of subchannels, and a size of an encoder packet. A modulation order and code rate decider receives, from the controller, the number of transmission slots, the number of OFDM symbols, the number of subchannels, and a size of an encoder packet, calculates a Modulation order Product code Rate (MPR), determines a modulation order according to the MPR, and outputs the determined modulation order to a corresponding physical channel.

The present invention is provided a method for allocating uplink resources in a communication system. The method includes calculating a scheduling metric for each Mobile Station (MS), selecting an MS with a high priority according to the scheduling metric, determining a Modulation order Product coding Rate (MPR) and a number of subchannels for the selected MS, and allocating the determined MPR and the determined number of subchannels to the selected MS and updating the scheduling metric for the each MS.

A transmitting apparatus and a receiving apparatus are provided. The transmitting apparatus includes an encoder configured to generate a low density parity check (LDPC) codeword by performing LDPC encoding, an interleaver configured to interleave the LDPC codeword, and a modulator configured to modulate the interleaved LDPC codeword according to a modulation method to generate a modulation symbol. The interleaver performs interleaving by dividing the LDPC codeword into a plurality of groups, rearranging an order of the plurality of groups in group units, and dividing the plurality of rearranged groups based on a modulation order according to the modulation method.

A method for retransmitting coded bits by a transmitter in response to a retransmission request from a receiver in a mobile communication system. The method comprises determining a modulation technique to be used at retransmission as a modulation technique having a lower modulation order than a modulation technique used at initial transmission; determining a puncturing pattern according to an HARQ (Hybrid Automatic Repeat Request) type, and selecting as many coded bits as the number of coded bits that can be symbol-mapped by the determined modulation technique, among the coded bits punctured by the determined puncturing pattern; and symbol-mapping the selected coded bits by the determined modulation technique, and transmitting the symbol-mapped coded bits to the receiver.

A transmitting apparatus and a receiving apparatus are provided. The transmitting apparatus includes an encoder configured to generate a low density parity check (LDPC) codeword by performing LDPC encoding, an interleaver configured to interleave the LDPC codeword, and a modulator configured to modulate the interleaved LDPC codeword according to a modulation method to generate a modulation symbol. The interleaver performs interleaving by dividing the LDPC codeword into a plurality of groups, rearranging an order of the plurality of groups in group units, and dividing the plurality of rearranged groups based on a modulation order according to the modulation method.

An apparatus and method are provided for normalizing input soft metric to a channel decoder in a wireless communication system. A demapper generates soft metric using an in-phase component (X_k) and a quadrature component (Y_k) of a received modulated symbol (R_k), a channel fading coefficient (g_k) and a constant value (c) defined by a modulation order of the received modulated symbol. A normalizer receives the soft metric, computes a normalized log likelihood ratio (LLR) by multiplying the soft metric by a ratio of the constant value to a noise variance value, transforms the normalized LLR into a desired range and a desired number of bits, and outputs an input LLR of the channel decoder.

A transmitting device, a receiving device, an optical communication system, and associated methods are provided. The transmitting device transmits an optical signal containing data, and comprises: an optical tone generator for generating at least one optical tone; at least one encoder for performing advanced coding on at least one data signal respectively, each of the at least one data signal carrying a part of the data; at least one mapper for performing high order modulation on the at least one coded data signal; and an up-converter for up-converting the at least one high-order-modulated data signal into the optical signal to be outputted through the at least optical tone. Thereby, high speed (e.g., over 1-Tb/s) transmission per single channel over a long-haul distance (e.g. over 1000-km) with error-free recovery may be achieved.

The invention supplies a method to gain the optimal guidance symbol power. It is used the factors that system noise signal ration in the channel estimating, base station and mobile platform relative move speed, coherent testing channel estimating interpolation filter coefficient and it depth, signal modulating module and the functional relation between the optimal guidance symbol power and the data symbol power ratio to gain the method used to gain the optimal power radio. The method of the invention is adopted to gain the optimal bit error ratio to the self-adapting OFDM system at the condition of giving the total emission power.

A unequal protection hybrid automatic retransfer request method based on equality and un-equality constellation diagram mapping, it is used in MQAM communication system with which the stage numbers is M and M=2, the modulation mapping of sending end and the resolving mapping of receiving end adopt constellation diagrams that have same distribution, in the first transmission and anterior m/2-1 time retransmission, adopts equality constellation diagram, at the m/2 time and the latter retransmission adopts un-equality constellation diagram, provides higher error protection for two most significant bit in the modification symbol; the bits un-equality protection in the modification symbol of sending end reset; uses m/2 reset and opposite reset rules, at different retransmission time adopts circularly in turn, achieves alternative protecting the bits in modulation symbol; the bits in modulation symbol of receiving end reset oppositely. Reset oppositely the bits according to the reset rules of sending end, recover it into bits sequence soft value before sending end bits resetting. It promotes the signals S/N of combining soft value after demodulating and resolving mapping at receiving end, reduces efficiently grouping retransmission time, makes the output of system maximum.

The present application relates to the field of wireless communications, and in particular, to an indication method and device for a modulation coding scheme. It is for solving the problem that in an existing LTE/LTE-A system, a higher-order modulation scheme cannot be supported, thereby limiting the further improvement of throughput in an application scenario of a high signal-to-noise ratio. The method of the embodiments of the present application includes: according to the channel quality and a first MCS table, a network side determining an MCS level corresponding to a channel scheduled for a UE; and by means of first indication information, notifying the UE of the determined MCS level, so as to indicate to the UE to determine a modulation scheme and code rate for the channel scheduled therefor according to the MCS grade, wherein there are at least corresponding entries of MCS indexes and TBS indexes corresponding to modulation schemes at higher modulation orders than 6 in the first MCS table. The embodiments of the present application introduce a higher-order modulation scheme into an existing LTE/LTE-A system, improving the spectrum efficiency.

A cable modem termination system (CMTS) may communicate with a plurality of cable modems using a plurality of orthogonal frequency division multiplexed (OFDM) subcarriers. The CMTS may determine a performance metric of each of the cable modems. For each of the OFDM subcarriers and each of the cable modems, the CMTS may select physical layer parameters to be used for communication with that cable modem on that OFDM subcarrier based on a performance metric of that cable modem. The parameters may be selected for each individual modem and/or each individual subcarrier, or may be selected for groups of modems and/or groups of subcarriers. The parameters may include, for example, one or more of: transmit power, receive sensitivity, timeslot duration, modulation type, modulation order, forward error correction (FEC) type, and FEC code rate.

A base station for use in a wireless network that communicates according to a multi-carrier protocol. The base station receives an uplink signal transmitted by a first subscriber station. The first subscriber station transmits using a configurable spectral shaping filter and a selectable modulation order. The base station determines a required bandwidth efficiency associated with the first subscriber station and, in response to the determination, selects a first modulation order and a first filter parameter to be used by the first subscriber station. Advantageously, the base station selects the first modulation order and the first filter parameter in order to maximize a power efficiency of the first subscriber station while maintaining the required bandwidth efficiency.

An apparatus is provided, including an observing function configured to observe an indication about the coverage status of a user equipment; a deciding function configured to decide, based on the indication, to switch into a coverage extension mode; a providing function configured to provide a scaling number in dependence of the coverage extension mode; an allocating function configured to allocate, for data to be transmitted to a user equipment, a first modulation and coding scheme, a first modulation order, a first size of a transport block, and a first number of resource blocks per transport block according to an orthogonal frequency division multiplexing technology, a reducing function configured to reduce a first size per resource block, being the quotient of the first size of the transport block and the first number of resource blocks per transport block, based on the scaling number, thus obtaining a second size per resource block, being the quotient of a second size of the transport block and a second number of resource blocks per transport block; and a scheduling function configured to schedule, for the data, the second size of the transport block and the second number of resource blocks per transport block.

A device and method of high-speed transmission is disclosed. The method includes computing a signal quality of a received signal, the received signal being transmitted with a modulation order required by a default transmission modulation format. The signal quality is compared with a signal quality threshold required of the default transmission modulation format. If the signal quality is below the signal quality threshold, an indication of a level of signal quality failure is provided to a transmitter. The transmitter sets a number of un-coded bits within the transmission signal based upon the level of signal quality failure.

This invention provides a channel interlacing method and a system in a handheld TV system, in which, the method includes: A, carrying out LDPC coding to input signal source bit streams to output LDPC coding blocks, B, carrying out bit interlacing among the blocks of LDPC, C, carrying out constellation mapping to the interlaced bits to generate constellation points, D, interlacing and mapping the points onto a time frequency plane of a multi-frame including multiple data frames to get an even better time diversity result , at the same time, bit information in a LDPC coding block can be scattered to irrelated data subcarriers by interlacing among LDPC coding blocks and interlaced mapping of constellation and different modulation steps can be processed together.

The invention discloses a trellis code modulated (TCM) code modulation method, and is to solve the problem of poor entirety of the prior TCM codes. The invention comprises the following steps. Firstly, a square QAM planisphere with the modulation order number larger than 4 is used as a constellation mapping scheme so that after the codes on a way I and a way Q of the constellation mapping scheme are mapped, and bit blocks are arranged repeatedly on a periodic basis on the ways I and Q, and corresponding uncoded bit blocks are different after each repeated arrangement on a periodic basis. Constellation indices including coded bit blocks and uncoded bit blocks are acquired according to original bit message block. Signaling points in the constellation mapping scheme according to the constellation indices are determined as the final emissive TCM signals. As the coded bit blocks are repeatedly arranged on a periodic basis, and corresponding uncoded bit blocks are different from each other, mappings of symbols for parallel paths on the way Q of the constellation mapping scheme are uniform, and the entirety of TCM codes can be improved.

An uplink scheduling apparatus and method in a communication system are provided. In the uplink scheduling method, a scheduling metric is calculated for each Mobile Station (MS). An MS with a high priority level is selected according to the calculated scheduling metric. The number of subchannels and a product of a modulation order and coding rate (MPR) are extracted according to input variables for the selected MS. The number of subchannels to be allocated to the selected MS is determined according to the MPR and the subchannels are allocated to the selected MS. The scheduling metric is updated for the each MS.