111111
`
`1111111111111111111111111111111111111111111111111111111111111
`US007616955B2
`
`c12) United States Patent
`Kim
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,616,955 B2
`Nov. 10, 2009
`
`(54) METHOD AND SYSTEM FOR BITS AND
`CODING ASSIGNMENT UTILIZING EIGEN
`BEAMFORMING WITH FIXED RATES FOR
`CLOSED LOOP WLAN
`
`(75)
`
`Inventor: Joonsuk Kim, San Jose, CA (US)
`
`(73) Assignee: Broadcom Corporation, Irvine, CA
`(US)
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 636 days.
`
`(21) Appl. No.: 11/052,389
`
`(22) Filed:
`
`Feb.7,2005
`
`(65)
`
`Prior Publication Data
`
`US 2006/0105767 Al
`
`May 18,2006
`
`Related U.S. Application Data
`
`(60) Provisional application No. 60/627,467, filed on Nov.
`12,2004.
`
`(51)
`
`Int. Cl.
`G06F 15116
`(2006.01)
`(52) U.S. Cl. ...................................... 455/434; 455/41.2
`(58) Field of Classification Search .............. 455/67.14,
`455/62, 63.3, 134, 138, 139, 423, 557, 434,
`455/41.2; 370/248, 346, 468
`See application file for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`12/1991 Mahany eta!.
`6/1995 Mahany
`8/1999 Kleider eta!.
`.............. 375/225
`5/2005 Polley eta!. ................ 455/105
`
`5,070,538 A
`5,425,051 A
`5,940,439 A *
`2005/0113041 A1 *
`* cited by examiner
`Primary Examiner-Sam Bhattacharya
`(7 4) Attorney, Agent, or Firm-McAndrews, Held & Malloy
`
`(57)
`
`ABSTRACT
`
`A method and system for bits and coding assignment utilizing
`Eigen beamforming with fixed rates for a closed loop WLAN
`is provided. Aspects of the method for communicating infor(cid:173)
`mation in a communication system may comprise transmit(cid:173)
`ting data via a plurality of radio frequency (RF) channels
`utilizing a plurality of transmitting antennas and receiving
`feedback information related to the plurality ofRF channels.
`Bits may be assigned for transmission via at least one of the
`plurality ofRF channels based on the feedback information.
`At least a portion of subsequent data having at least a first
`coding rate based on the assignment of bits may be transmit(cid:173)
`ted via at least one of the plurality of RF channels. The
`method may also comprise receiving data via a plurality ofRF
`channels utilizing a plurality of receiving antennas, and trans(cid:173)
`mitting feedback information related to the plurality of RF
`channels.
`
`30 Claims, 8 Drawing Sheets
`
`100a-----v
`
`~101a
`
`SONY EX. 1001
`Page 1
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`SONY EX. 1001
`Page 2
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`SONY EX. 1001
`Page 3
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`Figure 1c
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`Beamforming
`
`u· Matrix
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`End/
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`Antenna Front
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`• • • 116n
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`End/
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`Antenna Front
`
`116a
`
`100c--v
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`VMatrix
`
`Beamforming
`
`SONY EX. 1001
`Page 4
`
`

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`U.S. Patent
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`Nov. 10, 2009
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`
`Transmitting Station
`
`Allocation Information to
`
`Bit Allocation and Coding Rate
`Receiving Station Feeds Back
`
`510
`
`Modes
`
`Differences Among Spatial
`
`Signal to Noise Ratio
`
`Compensate for Residual
`Convolutional Coding to
`
`Set Coding Rate for Binary
`
`SOB
`
`Across Spatial Modes
`
`Determine Allocation of B Bits
`
`Use Aslanis Formula to
`
`506
`
`;---------111>1 Compute Geometric Mean SNR
`
`for Each of M Spatial Modes
`
`504
`
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`
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`
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`
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`
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`M Transmit Antenna;
`
`SONY EX. 1001
`Page 9
`
`

`

`US 7,616,955 B2
`
`1
`METHOD AND SYSTEM FOR BITS AND
`CODING ASSIGNMENT UTILIZING EIGEN
`BEAMFORMING WITH FIXED RATES FOR
`CLOSED LOOP WLAN
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS/INCORPORATION BY
`REFERENCE
`
`This application makes reference to, claims priority to, and
`claims the benefit of U.S. Provisional Application Ser. No.
`60/627467 filed on Nov. 12, 2004.
`This application also makes reference to U.S. patent appli(cid:173)
`cation Ser. No. 11/052,353 filed Feb. 7, 2005.
`All of the above stated applications are hereby incorpo(cid:173)
`rated herein in their entirety.
`
`FIELD OF THE INVENTION
`
`Certain embodiments of the invention relate to wireless
`networking. More specifically, certain embodiments of the
`invention relate to a method and system for bits and coding
`assignment utilizing Eigen beamforming with fixed rates for
`a closed loop wireless local area network (WLAN).
`
`BACKGROUND OF THE INVENTION
`
`The Institute for Electrical and Electronics Engineers
`(IEEE), in resolution IEEE 802.11, also referred as "802.11",
`has defined a plurality of specifications which are related to
`wireless networking. With current existing 802.11 standards,
`such as 802.11(a),(b ),(g), which can support up to 54 Mbps
`data rates, either in 2.4 GHz or in 5 GHz frequency bands, the
`IEEE standards body created a new task group, 802.11n, to
`support higher than 100 Mbps data rates. Among them are 35
`being discussed specifications for "closed loop" feedback
`mechanisms by which a receiving station may feed back
`information to a transmitting station to assist the transmitting
`station in adapting signals, which are sent to the receiving
`station. In closed loop feedback systems, a transmitting sta(cid:173)
`tion may utilize feedback information from a receiving sta(cid:173)
`tion to transmit subsequent signals in what is called "beam(cid:173)
`forming". Beamforming is a technique to steer signals to a
`certain direction for the receiver to receive it more reliably
`with less noise and interference. Compounded with demands
`for new features and capabilities, various proposals for new
`802.11n based feedback mechanisms are emerging to address
`the demand for these new features and capabilities. For
`example, there exists a demand for the introduction of new
`capabilities, which may enable a receiving mobile terminal to
`feedback pertinent information to a transmitting mobile ter(cid:173)
`minal. This feedback of pertinent information may enable the
`transmitting mobile terminal to adapt its mode of transmis(cid:173)
`sion based upon the feedback information provided by the
`receiving mobile terminal. As with any communication sys- 55
`tern, a major goal is to enable the transmitting mobile station
`to achieve a higher information transfer rate to the receiving
`mobile terminal, while simultaneously achieving a lower
`packet error rate (PER). Notwithstanding, there are no exist(cid:173)
`ing methodologies that adequately address these shortcom- 60
`ings and the demand for these new features and capabilities in
`WLANs.
`Further limitations and disadvantages of conventional and
`traditional approaches will become apparent to one of skill in
`the art, through comparison of such systems with some
`aspects of the present invention as set forth in the remainder of
`the present application with reference to the drawings.
`
`2
`BRIEF SUMMARY OF THE INVENTION
`
`Certain embodiments of the invention may be found in a
`method and system for bits and coding assignment utilizing
`5 Eigen beamforming with fixed rates for a closed loop WLAN.
`Aspects of the method for communicating information in a
`communication system may comprise transmitting data via a
`plurality of radio frequency (RF) channels utilizing a plural(cid:173)
`ity of transmitting antennas and receiving feedback informa-
`10 tion related to the plurality of RF channels. Bits may be
`assigned for transmission via at least one of the plurality of
`RF channels based on the feedback information, and at least
`a portion of subsequent data having at least a first coding rate
`based on the assignment of bits may be transmitted via the at
`15 least one of the plurality ofRF channels.
`The method may further comprise coding at least a portion
`of the assigned bits utilizing the first coding rate. The first
`coding rate may be computed based on received feedback
`information for transmitting at least a portion of the subse-
`20 quent data. The received feedback information may be based
`on channel estimation information for at least a portion of the
`plurality ofRF channels and/or signal to noise ratio informa(cid:173)
`tion for at least a portion of the plurality ofRF channels.
`In one aspect of the invention, the signal to noise ratio may
`25 be computed based on at least one transmitted tone for at least
`one of the plurality ofRF channels. At least a second coding
`rate may be computed based on the received feedback infor(cid:173)
`mation for transmitting at least a remaining portion of the
`subsequent data. At least a portion of the assigned bits may be
`30 coded utilizing the second coding rate. The method may
`further comprise transmitting at least the second coding rate
`via at least one of the plurality ofRF channels. Bits may be
`reassigned for transmission based on updated received feed-
`back information related to the plurality ofRF channels.
`In another embodiment of the invention, a method for
`communicating information in a communication system is
`provided. The method may comprise receiving data via a
`plurality of RF channels utilizing a plurality of receiving
`antennas. Feedback information related to the plurality ofRF
`40 channels may be transmitted and the transmitted feedback
`information may be utilized to assign bits for transmission via
`at least one of the plurality ofRF channels. At least a portion
`of subsequent data having at least a first coding rate may be
`transmitted based on the assignment ofbits via the at least one
`45 of the plurality ofRF channels.
`In one aspect of the invention, at least a portion of the
`assigned bits may be coded utilizing the first coding rate. The
`first coding rate may be computed based on the transmitted
`feedback information for transmitting at least a portion of the
`50 subsequent data. The transmitted feedback information may
`be based on channel estimation information for at least a
`portion of the plurality ofRF channels and/or signal to noise
`ratio information for at least a portion of the plurality ofRF
`channels.
`In one aspect of the invention, the signal to noise ratio may
`be computed based on at least one transmitted tone for at least
`one of the plurality ofRF channels. At least a second coding
`rate may be computed based on the transmitted feedback
`information and utilized for transmitting at least a remaining
`portion of the subsequent data. At least a portion of the
`assigned bits may be coded utilizing the second coding rate.
`The method may further comprise receiving at least the
`remaining portion of the subsequent data having at least the
`second coding rate via at least one of the plurality of RF
`65 channels. Bits may be reassigned for transmission based on
`updated transmitted feedback information related to the plu(cid:173)
`rality ofRF channels.
`
`SONY EX. 1001
`Page 10
`
`

`

`US 7,616,955 B2
`
`3
`Certain aspects of the system for communicating informa(cid:173)
`tion in a communication system may comprise a transmitter
`that transmits data via a plurality of RF channels utilizing a
`plurality of transmitting antenna. The transmitter may be
`adapted to receive feedback information related to the plural-
`ity ofRF channels and assign bits for transmission via at least
`one of the plurality of RF channels based on the feedback
`information. The transmitter may transmit at least a portion of
`subsequent data having at least a first coding rate based on the
`assignment of bits via the at least one of the plurality of RF 10
`channels.
`The system may further comprise a processor that codes at
`least a portion of the assigned bits utilizing the first coding
`rate. The processor may compute the first coding rate in the
`transmitter based on the received feedback information for 15
`transmitting at least a portion of the subsequent data. The
`received feedback information may be based on channel esti(cid:173)
`mation information for at least a portion of the plurality ofRF
`channels and/or signal to noise ratio information for at least a
`portion of the plurality ofRF channels.
`In one aspect of the invention, the signal to noise ratio may
`be computed based on at least one transmitted tone for at least
`one of the plurality ofRF channels.A processor may compute
`at least a second coding rate in the transmitter based on the
`received feedback information, which is utilized for transmit- 25
`ting at least a remaining portion of the subsequent data. The
`system may further comprise a coding processor that may
`code at least a portion of the assigned bits utilizing the second
`coding rate in the transmitter. The transmitter may be adapted
`to transmit at least the remaining portion of the subsequent 30
`data having at least the second coding rate via at least one of
`the plurality of RF channels. The transmitter may reassign
`bits for transmission based on updated received feedback
`information related to the plurality of RF channels.
`These and other advantages, aspects and novel features of 35
`the present invention, as well as details of an illustrated
`embodiment thereof, will be more fully understood from the
`following description and drawings.
`
`BRIEF DESCRIPTION OF SEVERAL VIEWS OF
`THE DRAWINGS
`
`FIG. la is an exemplary block diagram of a transmitter and
`a receiver in a MIMO system, in accordance with an embodi(cid:173)
`ment of the invention.
`FIG. lb is an exemplary block diagram of a transmitter
`with adaptive modulation and a corresponding receiver with
`adaptive demodulation for a MIMO system, in accordance
`with an embodiment of the invention.
`FIG.lc is an exemplary block diagram of a transmitter with
`adaptive modulation and coding, and a corresponding
`receiver with adaptive demodulation and decoding for a
`MIMO system, in accordance with an embodiment of the
`invention.
`FIG. 2 is an exemplary diagram illustrating Eigen beam(cid:173)
`forming in accordance with an embodiment of the invention.
`FIG. 3a is an exemplary histogram of probability density
`versus signal to noise ratio (SNR) for the square of singular
`value differences between the largest and the second largest
`singular values in the 2x2 system in RF channels of type
`channel B with rms delay spread of 15 ns as defined in IEEE
`802.11n, in accordance with an embodiment of the invention.
`FIG. 3b is an exemplary histogram of probability density
`versus signal to noise ratio (SNR) for the square of singular
`value differences between the largest and the second largest
`singular values in the 2x2 system in RF channels of type
`
`4
`channel D with rms delay spread of 50 ns as defined in IEEE
`802.11 n, in accordance with an embodiment of the invention.
`FIG. 4 is an exemplary diagram illustrating packet error
`rate (PER) versus SNR for various coding rates in binary
`convolutional coding (BCC), which may be utilized in con(cid:173)
`nection with an embodiment of the invention.
`FIG. 5 is a flow chart illustrating exemplary steps for bit
`and coding rate assignment using Eigen beamforming m
`accordance with an embodiment of the invention.
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`Certain embodiments of the invention may be found in a
`method and system for bits and coding assignment utilizing
`Eigen beamforming with fixed rates for a closed loop WLAN.
`Adaptive antenna and adaptive beamforming may be utilized
`to address at least some of the problems associated with signal
`loss of a transmitted signal as it traverses a communication
`link or medium. Adaptive antenna and adaptive beamforming
`20 utilizes various techniques to reduce interference within a
`communication medium. For example, adaptive antenna and
`adaptive beamforming may transmit directional signals to a
`receiving communication device via a narrow beam so as to
`reduce PER over the transmission medium. The reduced PER
`may result in much higher data rates and increased system
`capacity.
`In accordance with an embodiment of the invention, utiliz(cid:173)
`ing singular value decomposition (SVD), Eigen beamform(cid:173)
`ing may be applied to provide greater spatial spectrum effi(cid:173)
`ciency. Diagonalized singular values (D) may be utilized to
`provide better space mode with better signal quality. Further(cid:173)
`more, by assigning more bits on better space mode, the prob-
`ability of information loss in transmitted signals may be
`reduced.
`FIG. la is an exemplary block diagram of a transmitter and
`a receiver in a MIM 0 system, in accordance with an embodi(cid:173)
`ment of the invention. With reference to FIG. 1 is shown a
`transmitter lOOa and a receiver lOla. The transmitter lOOa
`may comprise a coding block 102, a puncture block 104, an
`40 interleaver block 106, a plurality of mapper blocks 108a ...
`l08n, a plurality of inverse fast Fourier transform (IFFT)
`blocks 11 Oa ... 11 On, a beamforming V matrix block 112, and
`a plurality of digital/analog (D/A) conversion/antenna front
`end blocks 114a ... 114n. The receiver lOla may comprise a
`45 plurality of antenna front end/analog/digital (A/D) conver(cid:173)
`sion blocks 116a ... 116n, a beamforming U* matrix block
`118, a plurality of fast Fourier transform (FFT) blocks
`120a ... 120n, a channel estimates block 122, a plurality of
`equalizer blocks 124a . . . 124n, a plurality of demapper
`50 blocks 126a ... l26n, a deinterleaver block 128, a depuncture
`block 130, and a Viterbi decoder block 132.
`In the transmitter lOOa, the coding block 102 may trans(cid:173)
`form received binary input data blocks by applying a forward
`error correction (FEC) technique such as, for example, binary
`55 convolutional coding (BCC). The application of FEC tech(cid:173)
`niques, also known as "channel coding", may improve the
`ability to successfully recover transmitted data at a receiver
`by appending redundant information to the input data prior to
`transmission via an RF channel. The ratio of the number of
`60 bits in the binary input data block to the number of bits in the
`transformed data block may be known as the "coding rate".
`The coding rate may be specified using the notion i6/t6 , where
`t6 represents the total number ofbits which comprise a coding
`group of bits, while i6 represents the number of information
`65 bits that are contained in the group of bits t6 . Any number of
`bits t6 -i6 may represent redundant bits which may enable the
`receiver lOla to detect and correct errors introduced during
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`5
`transmission. Increasing the number of redundant bits may
`enable greater capabilities at the receiver to detect and correct
`errors in information bits. The penalty for this additional error
`detection and correction capability may result in a reduction
`in the information transfer rates between the transmitter lOOa 5
`and the receiver lOla.
`The puncture block 104 may receive transformed binary
`input data blocks from the coding block 102 and alter the
`coding rate by removing redundant bits from the received
`transformed binary input data blocks For example, if the
`coding block 102 implemented a 1h coding rate, 4 bits of data
`received from the coding block 102 may comprise 2 informa(cid:173)
`tion bits, and 2 redundant bits. By eliminating 1 of the redun(cid:173)
`dant bits in the group of 4 bits, the puncture block 104 may
`adapt the coding rate from 1h to 2A The interleaver block 106 15
`may rearrange bits received in a coding rate-adapted data
`block from the puncture block 104 prior to transmission via
`an RF channel to reduce the probability of uncorrectable
`corruption of data due to burst of errors, impacting contigu(cid:173)
`ous bits, during transmission via an RF channel. The output 20
`from the interleaver block 106 may also be divided into a
`plurality of streams where each stream may comprise a non(cid:173)
`overlapping portion of the bits from the received coding rate(cid:173)
`adapted data block. Therefore, for a given number of bits in
`the coding rate-adapted data block, bd6, a given number of 25
`streams from the interleaver block 106, n5
`,, and a given num(cid:173)
`ber ofbits assigned to an individual stream i by the interleaver
`block 106, bs,(i):
`
`equation [1]
`
`6
`signals generated may be equal to the number of transmitting
`antenna at the transmitter lOOa. Each signal in the plurality
`generated by the beamforming V block 112 may comprise a
`weighted sum of at least one of the received composite
`OFDM signals from the IFFT blocks 110a ... 110n. The
`plurality of D/A conversion/antenna front end blocks
`114a ... 114n may receive the plurality of signals generated
`by the beamforming V matrix block 112, converting the digi(cid:173)
`tal signal representation received from the beamforming V
`10 matrix block 112 to an analog RF signal which may be ampli(cid:173)
`fied and transmitted via an antenna. The plurality of D/A
`conversion/antenna front end blocks 114a ... 114n may equal
`the number of transmitting antenna at the transmitter lOOa.
`Each D/A conversion/antenna front end block 114a . .. 114n
`may receive one of the plurality of signals from the beam(cid:173)
`forming V matrix block 112 and may utilize an antenna to
`transmit one RF signal via an RF channel.
`In the receiver lOla, the plurality antenna front end/AID
`conversion blocks 116a ... 116n may receive analog RF
`signals via an antenna, converting the RF signal to baseband
`and generating a digital equivalent of the received analog
`baseband signal. The digital representation may be a complex
`quantity comprising I and Q components. The number of
`antenna front end/AID conversion blocks 116a ... 116n may
`be equal to the number of receiving antenna at the receiver
`lOla. The beamforming U* block 118 may apply the beam-
`forming technique to the plurality of digital signals received
`from the plurality of antenna front end/AID conversion
`blocks 116a ... 116n. The beamforming U* block 118 may
`30 generate a plurality of signals where the number of signals
`generated may be equal to the number of streams utilized in
`generating the signals at the transmitter lOOa. Each signal in
`the plurality generated by the beamforming U* block 118
`may comprise a weighted sum of at least one of the digital
`35 signals received from the antenna front end/ AID conversion
`blocks 116a ... 116n. The plurality ofFFT blocks 120a ...
`120n may receive a plurality of signals from the beamforming
`U* block 118. The plurality ofFFT blocks 120a ... 120n may
`be equal to the number of signals generated by the beamform-
`40 ing U* block 118. Each FFT block 120a ... 120n may receive
`a signal from the beamforming U* block 118, independently
`applying ann-point FFT technique, demodulating the signal
`by a plurality of carrier signals based on the n sub-band
`frequencies utilized in the transmitter 1 OOa. The demodulated
`45 signals may be mathematically integrated over one sub band
`frequency period by each of the plurality of FFT blocks
`120a ... 120n to extract then symbols from contained in each
`of the plurality of OFDM signals received by the receiver
`lOla.
`The channel estimates block 122 may utilize preamble
`information contained in the received RF signal to compute
`channel estimates. The plurality of equalizer blocks 124a ...
`124n may receive symbols generated by the plurality ofFFT
`blocks 120a ... 120n. The plurality of equalizer blocks
`124a ... 124n may be equal to the number of FFT blocks
`120a . .. 120n. Each of the equalizer blocks 124a ... 124n
`may receive a signal from one of the FFT blocks 120a ...
`120n, independently processing the signal based on input
`from the channel estimates block 122 to recover the symbol
`originally generated by the transmitter lOOa. Each equalizer
`block 124a ... 124n may comprise suitable logic, circuitry,
`and/or code that may be adapted to transform symbols
`received from an FFT block 120a ... 120n to compensate for
`fading in the RF channel. The plurality of demapper blocks
`l26a ... l26n may receive symbols from the plurality of
`equalizer blocks 124a ... 124n, reverse mapping each symbol
`to a plurality of bits by applying a demodulation technique,
`
`The plurality of mapper blocks 108a ... l08n may com(cid:173)
`prise a number of individual mapper blocks which is equal to
`the number of individual streams generated by the interleaver
`block 106. Each individual mapper block 108a . .. l08n may
`receive a plurality of bits from a corresponding individual
`stream, mapping those bits into a "symbol" by applying a
`modulation technique based on a "constellation" utilized to
`transform the plurality of bits into a signal level representing
`the symbol. The representation of the symbol may be a com(cid:173)
`plex quantity comprising in-phase (I) and quadrature (Q)
`components. The mapper block 108a ... l08n for stream i
`may utilize a modulation technique to map a plurality of bits,
`bs,(i), into a symbol.
`The plurality of IFFT blocks 110a . .. 110n may receive
`symbols from the plurality of mapper blocks 108a . .. l08n 50
`where each IFFT block, such as 110a, may receive a symbol
`from a corresponding mapper block, such as 1 08a. Each IFFT
`block 110a ... 110n may subdivide the bandwidth of the RF
`channel into a plurality of n sub-band frequencies to imple(cid:173)
`ment orthogonal frequency division multiplexing (OFDM), 55
`buffering a plurality of received symbols equal to the number
`of sub-bands. Each buffered symbol may be modulated by a
`carrier signal whose frequency is based on that of one of the
`sub-bands. Each of the IFFT blocks 110a ... 110n may then
`independently sum their respective buffered and modulated 60
`symbols across the frequency sub-bands to perform an
`n-point IFFT thereby generating a composite OFDM signal.
`The beamforming V matrix block 112 may apply the beam(cid:173)
`forming technique to the plurality of composite OFDM sig(cid:173)
`nals, or "spatial modes", generated from the plurality ofiFFT 65
`blocks 110a ... 110n. The beamforming V matrix block 112
`may generate a plurality of signals where the number of
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`US 7,616,955 B2
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`7
`based on the modulation technique utilized in generating the
`symbol at the transmitter 100, to transform the symbol into a
`plurality of bits. The plurality of demapper blocks 126a ...
`l26n may be equal to the number of equalizer blocks
`124a ... 124n, which may also be equal to the number of 5
`streams in the transmitter lOOa.
`The deinterleaver block 128 may receive a plurality of bits
`from each of the demapper blocks 126a ... l26n, rearranging
`the order of bits among the received plurality of bits. The
`deinterleaver block 128 may rearrange the order of bits from 10
`the plurality of demapper blocks 126a . . . l26n in, for
`example, the reverse order of that utilized by the interleaver
`106 in the transmitter 100. The depuncture block 130 may
`insert "null" bits into the output data block received from the
`deinterleaver block 128 that were removed by the puncture 15
`block 104. The Viterbi decoder block 132 may decode a
`depunctured output data block, applying a decoding tech(cid:173)
`nique which may recover the binary data blocks that were
`input to the coding block 102.
`FIG. lb is an exemplary block diagram of a transmitter 20
`with adaptive modulation and a corresponding receiver with
`adaptive demodulation for a MIMO system, in accordance
`with an embodiment of the invention. With reference to FIG.
`lb is shown a transmitter lOOb, and a receiver lOlb. The
`transmitter lOOb may comprise a transmit modulation control 25
`block 136, and a plurality of blocks as shown in the transmit-
`ter lOOa (FIG.la). The receiver lOlb may comprise a receive
`demodulation control block 134, and a plurality of blocks as
`shown in the receiver lOla (FIG. la). The transmit modula(cid:173)
`tion control block 136 may enable control over the selection 30
`of modulation techniques utilized in the transmitter 1 OOb. The
`receive demodulation control block 134 may enable control
`over the selection of demodulation techniques utilized in the
`receiver lOlb. In operation, the transmit modulation control
`block 136 may enable control of modulation techniques 35
`applied by each of the plurality of mapper blocks 108a ...
`l08n individually, on a per-stream basis. The receive
`demodulation control block 134 may enable control of
`demodulation techniques applied by each of the plurality of
`demapper blocks 126a ... l26n individually, on a per-stream 40
`basis.
`In operation, per-stream control of the mapper blocks
`l08a ... l08n may control the number of bits assigned to one
`or more individual streams, bs,(i), to ensure that the sum of
`bits across the plurality of streams equals the aggregate num- 45
`ber ofbits in the coding rate-adapted data block, bd6 , as shown
`in equation[ 1].
`FIG.lc is an exemplary block diagram of a transmitter with
`adaptive modulation and coding, and a corresponding
`receiver with adaptive demodulation and decoding for a 50
`MIMO system, in accordance with an embodiment of the
`invention. With reference to FIG. lc is shown a transmitter
`lOOc, and a receiver lOlc. The transmitter lOOc may com(cid:173)
`prise a plurality of puncture blocks 1 OS a ... 1 05n, a plurality
`of interleaver blocks 107 a ... 1 07n, a transmit coding control
`block 140, and a plurality of blocks as shown in the transmit(cid:173)
`ter lOOb (FIG. lb). The receiver lOlc may comprise a plural-
`ity of deinterleaver blocks 129a . . . l29n, a plurality of
`depuncture blocks 13la ... 13ln, a receive coding control
`block 138, and a plurality of blocks as shown in the receiver
`lOlb (FIG. lb).
`In the transmitter lOOc, puncture and interleaving may be
`performed individually