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US 10,097,674 B2Granted
Single user OFDM with bit loading in wireless communications
AssigneeIntel Corporation
InventorsLaurent Cariou, Carlos Cordeiro
Life of this patent
Estimating the term…
Abstract
In single user OFDM wireless communication, the serial bit stream in a Medium access control Protocol Data Unit (MPDU) to be transmitted may be split up and routed in parallel through different encoding modules. In one embodiment the entire bit stream may be processed through an LDPC, and the output of the LDPC module split up before being routed to different Modulation Modules that each select a separate MCS for the associated sub-band. In another embodiment the bit stream may be split up before being processed separately through multiple LDPC modules, and the output of each LDPC module may then be routed to a different associated Modulation Module for selection of a separate MCS for the associated sub-band.
Claims17
A wireless communications device having a processor and a memory, the wireless communications device configured to:
- create a medium access control protocol data unit (MPDU);
- separate the MPDU into first and second groups of bits;
- subsequent to said separation of the MPDU into first and second groups of bits, apply a first low density parity check (LDPC) code by a first LDPC module to the first group of bits to produce a first bit string to be transmitted on a first sub-band;
- subsequent to said separation of the MPDU into first and second groups of bits, apply a second LDPC code by a second LDPC module to the second group of bits to produce a second bit string to be transmitted on a second sub-band;
- apply a first modulation and coding scheme (MCS) to the first bit string to produce a first MCS output;
- apply a second MCS to the second bit string to produce a second MCS output;
- map the first and second MCS outputs to a vector representing different sub-carriers of an orthogonal frequency division multiplex (OFDM) modulation, at sub-carrier locations corresponding to the first and second sub-bands;
- and
- transmit an OFDM symbol on the first and second sub-bands;
- wherein the first group of bits is to have a first number of bits equal to:
- (a number of sub-carriers on the first sub-band multiplied by a first number of bits intended per MCS symbol for the first sub-band) divided by (a first coding rate for the first sub-band), and wherein the second group of bits has a second number of bits equal to:
- (a number of sub-carriers on the second sub-band multiplied by a second number of bits intended per MCS symbol for the second sub-band) divided by (a second coding rate for the second sub-band).
9 more elements
A non-transitory computer-readable non-transitory storage medium that contains instructions, which when executed by one or more processors result in performing operations comprising:
- creating a medium access control protocol data unit (MPDU);
- separating the MPDU into first and second groups of bits;
- subsequent to said separation of the MPDU into first and second groups of bits, applying a first low density parity check (LDPC) code to the first group of bits to produce a first bit string to be transmitted on a first sub-band;
- subsequent to said separation of the MPDU into first and second groups of bits, applying a second LDPC code to the second group of bits to produce a second bit string to be transmitted on a second sub-band;
- applying a first modulation and coding scheme (MCS) to the first bit string to produce a first MCS output;
- applying a second MCS to the second bit string to produce a second MCS output;
- mapping the first and second MCS outputs to a vector representing different sub-carriers of an orthogonal frequency division multiplex (OFDM) modulation, at sub-carrier locations corresponding to the first and second sub-bands;
- and
- transmitting an OFDM symbol on the first and second sub-bands;
- wherein the first group of bits has a first number of bits equal to:
- (a number of sub-carriers on the first sub-band multiplied by a first number of bits intended per MCS symbol for the first sub-band) divided by (a first coding rate for the first sub-band), and wherein the second group of bits has a second number of bits equal to:
- (a number of sub-carriers on the second sub-band multiplied by a second number of bits intended per MCS symbol for the second sub-band) divided by (a second coding rate for the second sub-band).
9 more elements
A wireless communications device having means to:
- create a medium access control protocol data unit (MPDU);
- separate the MPDU into first and second groups of bits;
- subsequent to said separation of the MPDU into first and second groups of bits, apply a first low density parity check (LDPC) code to the first group of bits to produce a first bit string to be transmitted on a first sub-band;
- subsequent to said separation of the MPDU into first and second groups of bits, apply a second LDPC code to the second group of bits to produce a second bit string to be transmitted on a second sub-band;
- apply a first modulation and coding scheme (MCS) to the first bit string to produce a first MCS output;
- apply a second MCS to the second bit string to produce a second MCS output;
- map the first and second MCS outputs to a vector representing different sub-carriers of an orthogonal frequency division multiplex (OFDM) modulation, at sub-carrier locations corresponding to the first and second sub-bands;
- and
- transmit an OFDM symbol on the first and second sub-bands;
- wherein the first group of bits is to have a first number of bits equal to:
- (a number of sub-carriers on the first sub-band multiplied by a first number of bits intended per MCS symbol for the first sub-band) divided by (a first coding rate for the first sub-band), and wherein the second group of bits has a second number of bits equal to:
- (a number of sub-carriers on the second sub-band multiplied by a second number of bits intended per MCS symbol for the second sub-band) divided by (a second coding rate for the second sub-band).
9 more elements
A wireless communications device having a processor and a memory, the wireless communications device configured to:
- receive an orthogonal frequency division multiplex (OFDM) symbol over multiple sub-bands;
- translate the OFDM symbol into multiple signals, each signal representing a separate one of the multiple sub-bands;
- process each of the multiple signals with a separate modulation and coding scheme (MCS) to produce multiple demodulated bit strings;
- process each of the multiple demodulated bit strings through a separate reverse low density parity check (LDPC) code to produce multiple groups of bits;
- and
- combine the multiple groups of bits into a medium access control protocol data unit (MPDU);
- wherein each of the multiple group of bits is to have a quantity of bits equal to:
- (a number of sub-carriers on an associated sub-band) multiplied by (a number of bits intended for an associated MCS symbol) divided by (a first coding rate for the associated sub-band).
5 more elements
A non-transitory computer-readable non-transitory storage medium that contains instructions, which when executed by one or more processors result in performing operations comprising:
- receiving an orthogonal frequency division multiplex (OFDM) symbol over multiple sub-bands;
- translating the OFDM symbol into multiple signals, each signal representing a separate one of the multiple sub-bands;
- processing each of the multiple signals with a separate modulation and coding scheme (MCS) to produce multiple demodulated bit strings;
- processing each of the multiple demodulated bit strings through a separate reverse low density parity check (LDPC) code to produce multiple groups of bits;
- and
- combining the multiple groups of bits into a medium access control protocol data unit (MPDU);
- wherein each of the multiple group of bits has a quantity of bits equal to:
- (a number of sub-carriers on an associated sub-band) multiplied by (a number of bits intended for an associated MCS symbol) divided by (a first coding rate for the associated sub-band).
5 more elements
Dependencies are inferred from the claim text.