WO2016157510A1

WO2016157510A1 - A communication system and a transmitter

Info

Publication number: WO2016157510A1
Application number: PCT/JP2015/060535
Authority: WO
Inventors: James Awuor Okello
Original assignee: Nec Corporation
Priority date: 2015-03-27
Filing date: 2015-03-27
Publication date: 2016-10-06

Abstract

A method or a system for processing multiple streams of data by means of putting an identification on data at a transmitter in order to uniquely define the streams without adding specific redundant data such as pilot symbols to identify a transmitter' antenna; transmitting the processed data using at least one transmitter' antenna or one transducer through a medium, or storing the processed stream of data on a medium; and receiver for the receiving the transmitted or stored streams of data; where the transmitter includes a unit for generating phases that rotates the phases of modulated streams of data in such a manner that each stream has phases that changes with time, and do not correspond to originally modulated symbols in a stream. The transmitter may also have a matrix generator that combines at least two modulated symbols in a stream. On the other hand, the receiver has a signal separation unit or process with a unit for generating phases that are a conjugates of inverse of the phases that were used at transmitter side.

Description

Title of Invention: A COMMUNICATION SYSTEM AND A

TRANSMITTER

Technical Field

[0001] The present invention relates to a communication system and a transmitter. The

present invention relates to a system for assigning ID and transmitting data in the communications system with multiple transmitting modules.

Background Art

[0002] In a general communications system, data or signals to be transmitted are pre- processed to suit the medium through which the data is to be transmitted or stored. While the mode of data pre-processing for transmission may involve different methods depending on technology generation of a system, and the application of the communication system, a general approach is to divide the process through distinct layers with unique operations.

[0003] In the PL1 or PL2, channel coded data are processed in channel coding postprocessor, by possibly pruning off some bits to reduce coding rate, scrambling the pruned data, performing interleaving before symbol mapping of bits to a modulation scheme such as BPSK, QPSK, DQPSK among many possibilities. In the PL3, a tag is provided for each stream, where the tag is implemented using filters. In the PL4, each stream after modulation or mapping of bits to symbols such as BPSK, QPSK, and 16QAM is provided with a filter followed by a process that performs data scrambling and or interleaving.

[0004] NPL17 teaches about multiplying different streams of data using different phases. In this case, the different streams refer to parallel data streams that are mapped to different subcarriers of OFDM symbol. It is a kind of spread spectrum coded OFDM. In PL5, it talks about applying different phase rotation to different antennas. Further, these different phases are applied to a preamble (data or signal known by the receiver) rather than the data symbols. Further, as in NPL17, PL5 considers all the pilot symbols that are mapped on an OFDM symbol. Basically, the multiplications results in creating of delay spread that is different from each of the transmitting antenna. At the receiver, the known preamble and different phase shifts are used to estimate channel from each of the transmitting antennas. PL6 applies to HARQ, where blocks of data arc created. PL7 teaches about a method of multiplexing data with some known data that aids in identifying the target transmitted packets.

Citation List

Patent Literature [0005] [PL1] Japanese Patent Laid-Open No.Hl 1-2150921

[PL2] Japanese Patent Laid-Open No.H05-219488

[PL3] US Patent Publication No.7,760,758

[PL4] US Patent Publication No.8,411,779

[PL5] Japanese Patent Laid-Open No.2011-50061

[PL6] International Publication No.WO2008/050453

[PL7] Japanese Patent Laid-Open No.2005-318107

NON-PATENT LITERATURE

[0006] [NPL1] Part 11 : Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, IEEE Std 802.11, 1999 Edition, pp. iii.

[NPL2] Ki-Ho Kong, Yong-Wook Kim, Suki Kim, and Kwang-Hyun Baek, Senior Member, "A Power-Efficient Digital Amplifier Using Input Dependent Bit Flipping for Portable Audio Systems ," IEEE Transactions on Consumer Electronics, vol.56, no. 4, pp. 2406-2410, November 2010.

[NPL3] ITU towards "IMT for 2020 and beyond," www.itu.int, study groups, SG 5.

[NPL4] The Mobile Broadband Standard, www.3gpp.org

[NPL5] L. Hanzo, Y. Akhtman, L. Wang and M. Jiang, MIMO-OFDM for LTE, Wi- Fi and WiMAX - Coherent Versus Ncoherent and Cooperative Turbo-Transceivers, IEEE Wiley, Amazon Kindle Edition.

[NPL6] G.J. Foschini and M.J. Gans, "On limits of wireless communications in a fading environment when using multiple antennas," Wireless Personal Communications, vol. 6, pp. 311-335, 1998.

[NPL7] Vincent K. N. Lau, Yu-Kwong Ricky Kwok, Channel Adaptive Technologies and Cross Layer Designs for Wireless Systems with Multiple Antennas, Wiley Series in Telecommunication and Signal Processing, a John G. Proakis, Series Edition, pp.17- 18.

[NPL8] L. Hanzo, T.H. Liew, B.L.Yeup, Turbo Coding, Turbo Equalization and Space-Time Coding for Transmission over Fading Channels.

[NPL9] L. Hanzo, T.H. Liew, B.L.Yeup, Turbo Coding, Turbo Equalization and Space-Time Coding for Transmission over Fading Channels.

[NPL10] M.A. Khojastepour, W. Xiaodong, M. Madihian, "Design of Multiuser Downlink Linear MIMO Precoding Systems With Quantized Feedback," IEEE

Transactions on Vehicular Technology, vol.58 , Issue: 9 , pp. 4828 - 4836, 2009.

[NPL11] D.J. Dechene, A. Shami, "Energy Efficient Quality of Service Traffic Scheduler for MIMO Downlink SVD Channels," IEEE Transactions on Wireless Communications, vol.9, issue: 12, pp.3750 - 3761 , 2010.

[NPL12] L. Hanzo, M. Munster, B.J. Choi, T. Keller, OFDM and MC-CDMA for Broadband Multi-User Communications, WLANS and Broadcasting, IEEE Wiley. [NPL13] Xu Zhu, R.D. Murch, "Performance analysis of maximum likelihood detection in a MIMO antenna system," IEEE Transactions on Communications, vol. 50, issue.2, pp.187-191, 2002.

[NPL14] H. Claussen, H.R. Karimi, B. Mulgrew, "Layered encoding for 16- and 64-QAM iterative MIMO receivers," 5th European Personal Mobile Communications Conference, pp. 511 - 515, 2003.

[NPL15] A. Belouchrani and M.G. Amin, "Blind source separation based on time- frequency signal representation," EEEE Transactions on Signal Processing, Vol. 46, No.11 , pp. 2888-2897, November 1998.

[NPL16] Y. Li and K.J.R. Liu, "Adaptive blind source separation and equalization for Multiple-Input/Multiple-Output systems," IEEE Transactions on Information Theory, Vol.44, No.7, pp. 2864-2876, November 1998.

[NPL17] IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 51, NO. 7, pp.1123-1134, JULY 2003.

Summary of Invention

Technical Problem

[0007] The symbol mapping of the PL1 or PL2 could also be delayed and implemented in the following processing stages such as within the subcarrier mapping unit. A problem with using a linear filter as a tagging filter as indicated in the PL3 or PL4, is that such a method result in poor performance in mobile communication where channel characteristics of the medium 300 changes with time, such as in a case where a terminal is located in a moving car or train. This is due to their inherent delay within a filter.

[0008] In PL5, the phase difference between adjacent subcarrier must have a fixed phase.

The phase rotator as defined in PL5 changes with time (k), and need not have equal phase difference between adjacent subcarriers. The PL5 does not teach how

transmitted data can be detected at the receiver using multiple receiving antennas without using pilot or preamble symbols. The method of PL7 cannot be used to implement blind channel identification.

[0009] The present invention enables to provide a technique of solving the above-described problem.

Solution to Problem

[0010] One aspect of the present invention provides a communications system comprising:

a transmitter for-transmitting at-least one-stream of-signals through, a communication channel or a communication medium that is being shared with at least another transmitter or another stream; and

a receiver for receiving said at least one stream of signals from said transmitter, wherein said transmitter comprises: a divider that divides said at least one stream into at least one sub-stream to create a two dimensional map of data with sub-stream dimension having a sub-stream index and a time dimension having a time domain index;

a pre-processing unit that pre-processes said sub-streams; and

a post-processing unit that post-processes said pre-processed sub-streams using at least a filter,

wherein said pre-processing unit comprises:

a classifying unit that classifies data into groups of either scalar comprising a single subcarrier or vectors comprising multiple subcarrier, a second step of multiplying scalar groups using a phase rotator, and vector groups using matrices, and

wherein said receiver comprises:

a classifying unit that classifies received sub-streams from at least one receiving module using the same classification as the target stream of the transmitter; and at least one of a generation unit that generates a sequence of phases for multiplying scalar groups, and a creation unit that creates matrices for multiplying with the vector groups.

Another aspect of the present invention provides a communications system comprising:

a transmitter for transmitting at least one stream of signals through a communication channel or a communication medium that is being shared with at least another transmitter another stream; and

a receiver for receiving said at least one stream of signals from said transmitter, wherein said transmitter comprises:

a divider that divides said at least one stream into at least one sub-stream to create a two dimensional map of data with sub-stream dimension having a sub-stream index and a time dimension having a time domain index;

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

a classifying unit that classifies data into groups by including only one data sample in each of a first set of groups within which there is only one sub-stream index and one time domain index, and further creating a major group that includes at least two of said first set of groups with said first set of groups in the major group having same sub- stream index; and

a processing unit that processes said grouped data by creating a sequence of predetermined random phases having values within the range of zero and mathematical symbol 2pi, using said phases to generate a sequence of length equaling time domain index of said major group, with the resulting sequence being unique from at least a second major group of at least a second stream having the same sub-stream index as the first stream, and sharing the same channel as said first stream, using complex exponent of said sequence of phases to multiply and rotate phases of said data within said major group with same sub-stream index, and

wherein said receiver comprises:

a classifying unit that classifies received sub-streams from at least one receiving module into groups and major groups using the format of the transmitter; and a generation unit that generates a sequence of phases similar to the transmitter using pre-determined random phases having values within the range of zero and mathematical symbol 2pi, and

said receiver, in a first step, multiplies said received major groups from at least one receiving module with a sequence comprising complex conjugate of said complex exponent of said phases to generate modified sub-streams and, in a second step, combines with weighting factor, said modified sub-streams having the same sub- stream index and having been obtained from at least one of the receiving modules.

Still other aspect of the present invention provides a communications system comprising:

a transmitter for transmitting at least one stream of signals through a communication channel or a communication medium that is being shared with at least another transmitter or another stream; and

a divider that divides said at least one stream into at least two sub-stream to create a two dimensional map of data with sub-stream dimension having a sub-stream index and a time dimension having a time domain index;

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

a classifying unit that classifies data into a first set of groups with each said first set of groups including at least two data samples, said first set of groups each having at least two sub-stream indices and one time domain index to create a frequency domain vector, and further creating a major group that includes at least two of said first set of groups with all the groups in the major group having the same at least two sub-stream index; and

a processing unit that processes said grouped data by creating pre-determined random matrices, using said matrices for each time index to generate a sequence of matrices having a time domain length equaling time domain length of said major group, resulting said sequence of matrices being unique from at least a second sequence of matrices of a second major group of at least a second stream having the same said two sub-stream indices as the first stream's two sub-stream indices, said second stream sharing the same channel as said first stream, using said sequence of matrices having said at least two sub-stream indices to multiply said frequency domain vector, generating a matrix-modified at least two sub-stream of data with at least two indices of sub-stream and

wherein said receiver comprises:

a classifying unity that classifies received sub-streams from at least one receiving module into a first set of groups and major groups using the format of the transmitter to create a frequency domain vector; and

a generation unit that generates a sequence of matrices similar to the transmitter using pre-determined random matrices, and

said receiver, in a first step, multiplies said received frequency domain vector within major groups from at least one receiving module with a sequence comprising inverses of said sequence of matrices to generate modified sub-streams and, in a second step, combines with weighting factor, said modified sub-streams having the same sub- stream index and having been obtained from at least one of the receiving modules.

Yet other aspect of the present invention provides a communications system comprising:

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

a classifying unit that classifies data into a first set of groups with each said first set of groups including at least two data samples, said a first set of groups having at one sub-stream index and at least two time domain indices to create a time domain vector, and further creating a major group that includes at least one of said first set of groups with same sub-stream index; and a processing unit processes said grouped data by creating pre-determined random matrices having at least two time domain indices, using said matrices for each of said least two time domain indices to generate a sequence of matrices having same sub- carrier index as the major group, resulting said sequence of matrices being unique from at least a second sequence of matrices of a second major group of at least a second stream having the same said one sub-stream index as the first stream's sub-stream index, said second stream sharing the same channel as said first stream, using said sequence of matrices having said at least two time domain indices to multiply said frequency domain vector, generating a matrix-modified at sub-stream of data, and wherein said receiver comprises:

a classifying unit that classifies received sub-streams from at least one receiving module into a first set of groups and major groups using the format of the transmitter to create a time domain vector; and

said receiver, in a first step, multiples said received time domain vector within major groups from at least one receiving module with a sequence comprising inverses of said sequence of matrices to generate modified sub-streams and, in a second step, combines with weighting factor, said modified sub-streams having the same sub-stream index and having been obtained from at least one of the receiving modules.

Still yet other aspect of the present invention provides a communications system comprising:

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

a classifying unit that classifies data on two dimensional space of sub-stream domain and time domain into groups using a combination of at least two of methods of creating groups, processing the sections of said two dimensional space according to grouping format such that section of said map grouped are processed, wherein said receiver comprises:

a grouping unit that groups data on received sub-streams that have been mapped onto a two dimensional map such that each section of said two dimensional map is grouped according to the grouping format of the transmitter from which data is received.

[0015] Still yet other aspect of the present invention provides a transmitter for transmitting at least one stream of signals through a communication channel or a communication medium that is being shared with at least another transmitter or another stream, wherein said transmitter comprises:

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

a classifying unit that classifies data into groups by including only one data sample in each of a first set of groups within which there is only one sub-stream index and one time domain index, and further creating a major group that includes at least two of said first set of groups having said groups with same sub-stream index; and

a processing unit that processes said grouped data by creating pre-determined random phases within the range of zero and mathematical symbol 2pi, using said phases to generate a sequence of length equaling time domain index of said major group with the resulting sequence being unique from at least a second major group of at least a second stream having the same sub-stream index as the first stream and sharing the same channel as said first stream, using complex exponent of said phases to multiply and rotate phases of said data with same sub-stream index.

[0016] Still yet other aspect of the present invention provides a transmitter for transmitting at least one stream of signals through a communication channel or a communication medium that is being shared with at least another transmitter or another stream, wherein said transmitter comprises:

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

a classifying unit that classifies data into a first set of groups with each said first set of groups including at least two data samples, said first set of groups having at least two sub-stream indices and one time domain index to create a frequency domain vector, and further creating a major group that includes at least two of said first set of groups with same at least two sub-stream index; and

a processing unit that processes said grouped data by creating pre-determined random matrices, using said matrices for each time index to generate a sequence of matrices having a time domain length equaling time domain length of said major group, resulting said sequence of matrices being unique from at least a second sequence of matrices of a second major group of at least a second stream having the same said two sub-stream indices as the first stream's two sub-stream indices, said second stream sharing the same channel as said first stream, using said sequence of matrices having said at least two sub-stream indices to multiply said frequency domain vector, generating a matrix-modified at least two sub-stream of data.

Still yet other aspect of the present invention provides a transmitter for transmitting at least one stream of signals through a communication channel or a communication medium that is being shared with at least another transmitter or another stream, wherein said transmitter comprises:

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

a classifying unit that classifies data into a first set of groups with each said first set of groups including at least two data samples, said first set of groups having at one sub-stream index and at least two time domain indices to create a time domain vector, and further creating a major group that includes at least one of said first set of groups with same sub-stream index; and

a processing unit that processes said grouped data by creating pre-determined random matrices having at least two time domain indices, using said matrices for each of said least two time domain indices to generate a sequence of matrices having same sub- carrier index as the major group, resulting said sequence of matrices being unique from at least a second sequence of matrices of a second major group of at least a second stream having the same said one sub-stream index as the first stream's sub-stream index, said second stream sharing the same channel as said first stream, using said sequence of matrices having said at least two time domain indices to multiply said frequency domain vector, generating a matrix-modified at sub-stream of data. [0018] Still other aspect of the present invention provides a transmitter for transmitting at least one stream of signals through a communication channel or a communication medium that is being shared with at least another transmitter or another stream, wherein said transmitter comprises:

a dividing unit that divides said at least one stream into at least one sub-stream to create a two dimensional map of data with sub-stream dimension having a sub-stream index and a time dimension having a time domain index;

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

a classifying unit that classifies data on two dimensional space of sub-stream domain and time domain into groups using a combination of at least two of methods of creating groups, processing the sections of said two dimensional space according to grouping format such that section of said map grouped are processed, section of said map grouped are processed, and section of said map grouped are processed.

Advantageous Effects of Invention

[0019] According to the present invention, channel capacity in a communication system can be improved by avoiding or minimizing transmission of pilot symbols, or multiplexing signals using ID.

Brief Description of Drawings

[0020] [fig.lA]Fig. 1A is a block diagram illustrating fundamental constitution of a communication system with a transmitter unit having at least one transducer for converting signals to a suitable format for transmitting through a medium, or storage on a medium, and a receiver unit with at least one transducer for converting information or signals transmitted through a medium, or storage medium.

[fig.lB]Fig. IB is a block diagram illustrating the transmitting unit or system with multiple modules each having at least one transducer for transforming signals or data to a suitable format for transmitting through a medium, or storage on a medium, and a link that enables exchange of information between the modules.

[fig.lC]Fig. 1C is a block diagram illustrating the receiving unit or system with multiple modules each having at least one transducer for transforming signals or data from a medium or a storage device, for further processing.

[fig.2]Fig. 2 is a block diagram of a generalized baseband (BB) and radio frequency (RF) unit based on orthogonal frequency division multiplexing (OFDM) and transmissions in parallel of at least two streams.

[fig.3]Fig. 3 is a diagram of an OFDM frame of one of the data streams illustrating time domain and frequency domain in an OFDM frame, and example of subcarriers used to transmit pilot symbols that are used by a receiver unit to estimate channel or medium characteristics.

[fig.4]Fig. 4 is a block diagram of a generalized receiver for receiving simultaneously at least two signal streams, and processing the streams based on orthogonal frequency division multiplexing (OFDM), and constituting a channel estimation and equalization unit.

[fig.5]Fig. 5 is a block diagram of generalized prior art (technology) for channel estimation and equalization unit in an OFDM receiver with channel estimation being done using a pilot data received on number of subcarriers, and channel equalizer and interference cancellation or reduction unit or process.

[fig.6]Fig. 6 is the block diagram showing a generalized baseband model for tagging in a multiple-input multiple-output (MIMO) system with optional post-tagging processing that could include an interleaver and a scrambler as detailed explained in prior inventions.

[fig.7A]Fig. 7A is a block diagram of classifying the subcarriers according to this invention.

[fig.7B]Fig. 7B is a block diagram of classifying the subcarriers according to this invention where different streams could have classification of subcarriers in groups that do not completely overlap according to this invention. It also indicates a diagram of an OFDM frame of one of the data streams illustrating time domain and frequency domain in an OFDM frame, and example of location of a single subcarrier, at least two subcarriers along time domain, at least two subcarrier along frequency domain that can be tagged individually or jointly in case of multiple subcarriers, and it also indicates example of how different vectors can be generated by selecting different subcarriers within a region of an OFDM frame.

[fig.8]Fig. 8 is a block diagram illustrating a tagging scheme using random phases hereafter called a tagging phase (TP), for tagging data streams on OFDM subcarriers in a transmitting unit with at least two data streams.

[fig.9]Fig. 9 is a block diagram illustrating a generalized baseband model for tagging in a multiple-input multiple-output (MIMO) transmitting system using tagging matrix and at least two subcarriers in the frequency domain of OFDM frame.

[fig.lO]Fig. 10 is a block diagram illustrating a generalized baseband model for tagging in a multiple-input multiple-output (MIMO) transmitting system using tagging matrix and two subcarriers in the time domain of OFDM frame.

[fig.l l]Fig. 11 is a block diagram that illustrates how different modes using matrices (time domain, frequency domain) and phases can be combined into a single transmitting system. [fig.l2]Fig. 12 is a block diagram illustrating a section of OFDM receiver with at least two OFDM streams and inverse tagging phase (ITP), for equalizing and removing interference from target subcarriers that were transmitted using an OFDM transmitting unit with tagging phases.

[fig.l3]Fig. 13 is an alternative block diagram illustrating a section of OFDM receiver with at least two OFDM streams and inverse tagging phase (ITP), for equalizing and removing interference from target subcarriers that were transmitted using an OFDM transmitting unit with tagging phases.

[fig.l4]Fig. 14 is a block diagram illustrating a section of OFDM receiver with at least two OFDM streams and inverse tagging matrix (ITM), for equalizing and removing interference from target subcarriers that were transmitted using an OFDM transmitting unit with tagging matrices on OFDM frame along frequency domain, with receiver combining signals after removing the ID.

[fig.l4A]Fig. 14A is a block diagram illustrating a section of OFDM receiver with at least two OFDM streams and inverse tagging matrix (ITM), for equalizing and removing interference from target subcarriers that were transmitted using an OFDM transmitting unit with tagging matrices on OFDM frame using a vector created along frequency domain.

[fig.l5]Fig. 15 is a block diagram illustrating a section of OFDM receiver with at least two OFDM streams and inverse tagging matrix (ITM), for equalizing and removing interference from target subcarriers that were transmitted using an OFDM transmitting unit with tagging matrices on OFDM frame using a vector created a long time domain. Description of Embodiments

[0021] Preferred embodiments of the present invention will now be described in detail with reference to the drawings. It should be noted that the relative arrangement of the components, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless it is specifically stated otherwise.

[0022] These embodiments relate to a method for use in transmitting multiple streams of data and a method for receiving signal in a system where multiple streams of data are transmitted through the same medium or channel, wherein all the streams use the same channel, and where same channel refers to sharing the same frequency, same spreading code as in code division multiple access (CDMA), same space as in a sector or cell of a cellular system, and same time slot, with a receiver that does not use any redundant data such as pilot symbols for channel identification, equalization or signal separation. The invention also relates to any systems that can be modeled as a multiple-input multiple-output, a corresponding signal processing device, a corresponding signal processing system and a corresponding software application. More specifically, it relates to a technique for improving channel capacity in a communication system by avoiding or minimizing transmission of pilot symbols, or multiplexing signals using ID.

[0023] (Precursor Technology)

The precursor technology for the present embodiments will be mentioned thereinafter before the description of the embodiments

[0024] In a general communications system, data or signals to be transmitted are pre- processed to suit the medium through which the data is to be transmitted or stored. While the mode of data pre-processing for transmission may involve different methods depending on technology generation of a system, and the application of the communication system, a general approach is to divide the process through distinct layers with unique operations. In one of the examples of a communication system such as a wireless local area network (WLAN) NPL1, there is provided a MAC layer that schedules data to be transmitted and physical layer (PHY) that processes the data to a mode suitable for transmission. The PHY layer is further divided into baseband (BB) processing and radio frequency (RF) processing. While previous methods of implementation implied RF processing is in an analogue domain, recent advancement in digital signal processing has enabled part of RF processing to be done using efficient digital signal processing technology, such as in digital amplifier NPL2.

[0025] Further, international telecommunication union radio communication (ITU-R) has been advancing technologies that enable efficient usage of radio spectrum NPL3, by encouraging development of future radio communication technologies which efficiently utilize radio frequency spectrum. Some of the technologies that have been identified to date that enable this advancement include the long term evolution (LTE) technology that was developed by the third generation partnership project (3GPP) standardization organization NPL4. LTE standard among other related standards, includes orthogonal frequency division multiplexing (OFDM) technology that was first proposed by Chang NPL5, otherwise known as Discrete Multi-Tone transmission, and a Multi-Input Multi-Output (MIMO) that enables transmission of multiple streams of data using the same channel. It has been taught by Foschini NPL6 that the more transmit antennas and receive antennas we use in a wireless communication, the greater the channel capacity. In fact, channel capacity between two terminals increases linearly as a function of number of transmit antennas, when number of receive antenna are the same as number of transmit antennas.

[0026] In an OFDM system, frequency is divided into a number of orthogonal frequency channels, otherwise known as subcarriers, where in a frequency selective channel NPL7, each of the OFDM subcarriers can be considered to be experiencing a flat fading. Therefore, a signal yi(k) of a receiver at OFDM subcarrier with index "1" modeled mathematically as in Eq.(l).

[Math.l]

y_l(k) = x_l(k)h _l+s_l(k) ^■■■ (1 )

where Xi(k) is the signal that was mapped to subcarrier with index "1", h,(k) is the channel gain or loss experienced at subcarrier with index "1" and Si(k) is the noise at the receiver experienced at subcarrier with index "1", and "k" is a time index of OFDM symbol.

[0027] On the other hand in MIMO-OFDM, signals transmitted by multiple antennas are processed using OFDM, while the receiver implements inverse OFDM operation. Fig. 1 A is a block diagram illustrating an example of fundamental constitution of a communication system with a transmitter 100 with transmission system 120 having at least one transmitting antenna (or transmitting module), antenna#l 190, or antenna#2 191 for converting signals 103,105 to a format 301,303 suitable for transmitting through a medium 300, which in a MIMO-OFDM wireless system is space, and a receiver system 200 with at least one antenna, antenna#l 290, or antenna#M 291 for converting information or signals transmitted through air (or other medium) 302, 304 into a format 203, 205 that can be processed further by a receiver unit 220 in order to retrieve the target originally transmitted signals signal#l 102, or signal#N 104. These two signals respectively correspond to signal#3 202 and signal#4 204 at the receiver.

[0028] In this present innovation, and as an example, it is considered in general that a

transmitter 100 with a transmitting system 120 has "M" antennas, antenna#l 190 to antenna#M 191, which are used at the transmitter, and "N" antennas, antenna#l 290 to antenna#M 291, which are used at the receiver side. In this case and while taking into account flat fading on each subcarrier of an OFDM symbol marked as symbol "k", and that multiple receiver antennas are used, and therefore signals received by all the receive antennas at subcarrier index "1" can be modeled mathematically with the receiver system 220 as in Eq.(2).

[Math.2]

where x_m,i(k) is the signal that was mapped to antenna of transmission module with index "m", subcarrier with index "1" of the "k*" OFDM symbol, h_{n m l}(k) is the channel gain or loss experienced at subcarrier with index "1" between the "m⁴" transmit antenna and "n^th" receive antenna, and s_n ,(k) is the noise at the receiver experienced at subcarrier with index "1" of the "n*" receive antenna.

[0029] While Eq.(2) illustrates a single MIMO system, the transmitter 100 could be constituted of at least two transmitting subunits (or sub-systems), unit#l 121 and unit#2 122, as shown in Fig. IB, where unit#l has at least one transmit antenna 190, and unit#2 also has at least one transmit antenna 192. These two units, unit#l 121 and unit#2 122, could be co-located or distributed in space, but can have the possibility to exchange information using a link 120-1; the link 120-1 of which could be wireless, optical or any other media that enables communication between the two units 121, 122. This kind of implementation is normally referred to as coordinated transmission NPL5. An alternative name includes coordinated multipoint (CoMP) transmission.

[0030] Similarly, as shown in Fig. 1C, the receiver 200 with a receiving unit 220, could be implemented using at least two receiving sub-units, sub-unit#l 221 and subunit#2 222. As in the case of transmitting unit 120 in Fig. IB, the receiving subunits in Fig. 1C are implemented using a method where, sub-unit#l 221 has at least one receiving antenna 290, while subunit#2 has at least one receiving antenna 292. Further, the two subunits, subunit#l 221 and subunit#2 222, could be co-located or distributed in space, but could also have the possibility to exchange information using a link 220-1 ; the link 220-1 of which could be wireless, optical or any other media that enables communication between the two subunits, subunit#l 221, and subunit#2 222. This kind of implementation is normally referred to as coordinated reception, or alternatively as coordinated multipoint (CoMP) reception.

[0031] Fig. 2 is a block diagram illustrating additional details on one of the methods for implementing transmitting unit 120 in Fig. 1, or subunit 121, 122 in Fig. IB. In practice, the mode of implementation varies from one system to another, as it will be apparent to anyone who has expertise in this field of invention. In Fig. 2, there is a preprocessing unit 1201, also considered as MAC unit that receives signals 102, 104 to be

transmitted, and schedules, adds headers or even concatenate blocks of data to generate at least one data stream 1241 with blocks of data for processing in a baseband area. The data stream 1241 from MAC could then be scrambled using a scrambler 1202. The Cyclic Redundancy Check(CRC) check bits are added to the blocks of data 1242 so as to enable detection of errors at the receiver 220. In addition, depending on channel condition of the medium 300, blocks of data 1243 with CRC bits could be joined to create larger blocks, or broken down into sub-blocks, in a channel coding preprocessing unit 1204, with the resulting blocks 1244 being coded with a coding scheme 1205 such as convolution coding NPL8, Turbo coding NPL8 or any other channel coding method. Further, channel coded data 1245 are processed in channel coding post-processor 1206, by possibly pruning off some bits to reduce coding rate, scrambling the pruned data, performing interleaving [PL1, PL2] before symbol mapping of bits to a modulation scheme such as BPSK, QPSK, DQPSK among many possibilities. Note that symbol mapping could also be delayed and implemented in the following processing stages such as within the subcarrier mapping unit 1208.

[0032] Since this patent considers transmission using at least one stream and a second

transmitter (or multiple streams), channel coded and post-processed data 1246 as indicated in Fig. 2, are mapped to at least two streams using a sublayer mapping unit

1207 to generate at least two streams of data, data#l 1247 and data#2 1248. Alternatively, a second stream could be generated separately using a second signal 1241 from the processing using 1201, or from a different transmitter unit 122, where unit#l 121 and unit#2 may or may not coordinate using the link coordination route 120-1. Further, the respective at least two streams, stream#l 1247, and stream#2 1248, are mapped to subcarriers of an OFDM symbol using a subcarrier mapping unit 1208. As said earlier, it is possible to consider a single stream.

[0033] Now, if data bits have not been mapped to a modulation scheme such as BPSK,

QPSK, DQPSK, among many possibilities within the channel coding post-processor 1206 (or channel sublayer mapping unit (1207), the bits will be mapped to a modulation scheme within subcarrier mapping unit 1208. The subcarrier mapping unit

1208 generates multiple modulated data for different subcarriers, with the mapping index corresponding to physical subcarrier index, or a logical subcarrier index. In addition, pilot symbols are mapped at specific subcarriers, and OFDM symbols, in order to enable channel estimation associated with each stream of data as illustrated in an example provided in Fig. 3, where in this example, subcarriers 401-1 are used to map pilot symbols of one stream, while subcarriers 401-2 are used to map pilot symbols of a second stream. Fig. 3, 20 also illustrates the direction of frequency domain 460 with some of subcarriers' indices 460-1, 460-2 and 460-5 provided, where these indices could be logical or physical as explained earlier. Further, it illustrates the time domain 440 that defines OFDM symbol index, such as index number 1, 440-1, and index number 9, 440-9. These indices shall also be referred to as the time index.

[0034] An optional precoding unit 1210 in Fig. 2 could also be provided to optimize

transmission using a precoding matrix NPL9 that is related to channel 300 characteristics. Alternatively, the precoding unit 1210 could be used independently as a tagging unit as will be evident in later description, or by using channel related information such as in the case of singular value decomposition approach NPL11. In 3 GPP standard, and IEEE WLAN standard, these channel related information are estimated using pilot symbols. The precoding unit generates data ranging from data#l 1254, to data#L 1255 that are mapped to OFDM subcarriers. An OFDM operation using IFFT or any other filter bank is performed on a block of data 440-1, 440-9 and any other block of data mapped to a two dimensional space of an OFDM subcarrier as shown of Fig. 3, and addition of Cyclic Prefix is performed on precoded data 1254 to

1255, in order to generate OFDM symbols 1258 that are processed further in a Post- OFDM processing unit 1213, as shown in Fig. 2. The first block of data 440-1 in Fig. 3 can be consider has generating the first OFDM symbol, while the ninth block of data 440-9 can be considered has generating the ninth OFDM symbol, or an OFDM symbol at the ninth time index. OFDM symbols 1258 are then processed in the post-OFDM processing unit 1213 in Fig. 2. This unit 1213 could include a second filter for limiting the frequency band of OFDM symbols in addition to sub-band filter of OFDM, an oversampling unit, an amplifier, a predistortion unit and modulation to a carrier frequency specified for the target application, resulting in at least one analogue signals, signal#l 103 or signal#2 105 which are then transmitted using at least one antenna 190 as shown in Fig.1.

[0035] At the receiver 220 whose details are provided in example of Fig. 4, at least two signals, signal#l 203 and signal#2 205 are received, and each is processed by a pre- OFDM processing unit 2213 to generate digital baseband (BB) signals, signal#l 2258 and signal#2 2259. The pre-OFDM processing unit 2213 of the receiver 220 includes but not limited to functions such as amplifiers, gain control, frequency and clock synchronization, filters to reject unwanted signals in a different frequency band and analogue to digital converter. The resulting signal 2258 is then processed using an inverse OFDM processing unit 2211, where cyclic prefix or a guard interval is removed from synchronized OFDM symbols, before implementing FFT (or inverse sub-band filtering) operation to generate multiple signals corresponding to each subcarrier of an OFDM symbol as illustrated in Fig. 3. There is at least two signals or data (2254 to 2255) from inverse OFDM 2211 of the first stream, and the output from inverse OFDM 221 1 comprising at least two outputs (or subcarrier), output#l 2254 and output#2 2255. Corresponding outputs, output#l 2254 and output#3 2256, are jointly processed in a channel estimation and equalization unit 2210 to generate at least two data sub-streams, sub-stream#l 2250 and sub-stream#2 2251, and another at least two data streams, sub-stream#3 2252 and sub-stream#3 2253, corresponding to signals of at least two streams 1247 and 1248 that were mapped to OFDM and CP (Cyclic Prefix) processing unit 1211, 1212 at the transmitter.

[0036] In one of examples 400, as shown in Fig. 5, the channel estimation and equalization unit 2210 utilizes pilot symbols such as symbols mapped to 401-1 of Fig. 3 for the first stream, and 401-2 for the second stream as illustrated in Fig. 3 in order to estimate channel 300 characteristics using a channel estimation unit 406 in Fig. 5. The channel estimation unit generates at least one channel matrix 407 for subcarriers of interest within the OFDM symbols or frames. Fig. 5 illustrates one of the methods for channel estimation and interference cancellation or equalization. In this example Fig. 5, channel estimation unit 400 selects only data 401, 402 that were mapped to pilot locations 401-1, 401-2, for the case of two streams, or 401-1, 401-2, 401-3, 401-4, 401-5 for the case of five streams. Methods for channel estimation are well documented in literature NPL5, NPL12. Channel equalization unit 408 equalizes data on at least one subcarrier, subcarrier 2254 to subcarrier 2255, and subcarrier 2256 to subcarrier 2257, to generate desired data 411 to data 412 corresponding to first stream 2250, and desired first data 413 to desired another data 414 corresponding to the second stream. In practice, channel equalization may be done by zero forcing (ZF), minimum mean square error (MMSE), maximum likelihood detection (MLD) NPL13, or any other method, including recursive methods NPL14 that refine the quality of estimated channel matrices 407, by getting a feedback 405 of correctly or partially decoded data from the channel decoding unit 2205, and included in channel estimation unit 405, or channel equalization and interference cancellation unit 408 in order to improve performance.

[0037] Equalized data, first group of first data stream 2250 to last data stream 2251, and a second group of first data 2252 to the last data 2253 are demapped from the subcarriers to obtain streams 2247 and 2248 of received data. The demapper could also include a process for creating soft bits from modulated symbols. The at least two streams 2247 and 2248 are further combined in a channel sublayer demapping unit 2207 to create a single stream 2246 with at least one block of channel coded data. The single stream 2246 with at least one block of channel coded data could involve further processing in the channel decoding pre-processing unit 2206, where deinterleaving, descrambling, and division into necessary number of channel coded blocks that were individually decoded in the channel decoding unit 2205 to generate blocks of data bits that could be divided further into smaller blocks in a channel decoding post-processing unit 2204 to generate smaller blocks 2243 for checking error. For each block 2243, CRC bits are checked using a CRC check and removal unit 2203. If no error is reported, the smaller blocks 2243 could be used to refine channel estimation in the channel estimation unit. The error free blocks could also be used in successive interference equalization as a signal 405 as shown in Fig. 5 to improve performance of a MIMO system.

[0038] As was illustrated in Fig. 3, the more streams are transmitted, or the more transmit antennas are used, the more subcarrier need to be allocated for pilot symbols. This creates a problem where subcarriers that could be used to carry data ends up being used by pilot symbols hence reducing the maximum possible rate of data transmission. While several methods have been invented NPL15, NPL16 to avoid using pilot symbols, these methods do not directly separate the transmitted streams into a known format, resulting in what is known as permutation or ambiguity in antenna or stream domain[PL3][PL4]. Thus, after blind channel estimation and equalization in unit 2210, data 2250 at the receiver may not correspond to data 1250 at the transmitter. The same applies to other subcarriers, such that data 2252 may not correspond to data 1252 at the transmitter. Thus, retrieving the individual streams 1247, 1248 using a blind method results in streams 2247 and 2248 where data in the first stream 2247 contains both data from first stream 1247 and the second stream 1248. This problem is referred to as permutation or ambiguity in antennas, or ambiguity in streams of transmitted data.

[0039] (Problems of the precursor technologies)

In one of the prior inventions that provides solutions to permutation problem, a tag is provided for each stream, where the tag is implemented using filters PL3. In another method, each stream after modulation or mapping of bits to symbols such as BPSK, QPSK, and 16QAM is provided with a filter followed by a process that performs data scrambling and or interleaving [PL4], a combination of filter and at least scrambling or interleaving, or both scrambling and interleaving contributing to a tag that is used in identifying a target stream. These two methods can be generalized as tagging based approach, and one of the examples of implementing the transmitter is provided in Fig. 6, where the tagging unit 120-3 performs the tagging process on each subcarrier. In this figure there is tagging filter (TF) 120-1 that filters data 1250 that have been mapped to subcarriers of OFDM symbol. The filtered data 1250-1 are further processed using optional post tagging filter (TF) processing that comprises a scrambler or an interleaver, or both a scrambler and an interleaver. A problem with using a linear filter as a tagging filter as indicated in [PL3][PL4] is poor performance in mobile communication where channel characteristics of the medium 300 changes with time, such as in a case where a terminal is located in a moving car or train. This is due to their inherent delay within a filter.

[0040] Thus, the major problem which this innovation intends solves is to avoid or minimize the use of pilot symbols in a communication system, since the position occupied by such symbols can be used to transmit data, hence improving on the data rate. An additional problem is to avoid the problem of permutation in a multiple-input multiple- output system, where pilot symbols are not used to estimate channel. A third problem is reducing delay of signal processing where there is provided at least one transmitter sharing a communication channel with at least a second transmitter.

[0041] Therefore, the object of the present invention is to provide a blind channel estimation and equalization of a multi-stream communication systems using a method or program or apparatus that can perform blind equalization and separate streams at a receiver, or retrieve only the desired stream without having a situation where data components of at least a second stream are still available in the first desired stream. The objective of this invention is also to provide a blind channel estimation and equalization of a multi- stream in a communication system using a method or program or apparatus that can perform blind equalization and separate streams at a receiver that is in motion, hence creating an environment with time selective fading where the channel 300 changes fast.

[0042] (Structure of the embodiments)

According to the first aspect of this invention, there is provided a block or frame of OFDM symbols or symbols of a sub-bank filter, constituting at least two OFDM symbols, the OFDM operation of which can be done using FFT, IFFT or any kind of multi-band filtering with each band considered as a subcarrier, where in first frame of OFDM symbol corresponding to one stream of data, there are at least one subcarriers, and at least two symbols, and the subcarriers can be classified as a scalar with at least a single subcarrier (460-1,440-1) as indicated in example of Fig. 7, or as vector with at least two frequency domain subcarriers (460-8:460-9,440-1), or as vector with at least two time domain subcarriers (460-1,440-4:440-5), or at least two frequency domain subcarriers and at least two time domain subcarriers (460-8:460-9,440-12:440-13) as in the case of vector-A and vector-B; in the second frame of OFDM symbols corresponding to second stream of data if available, there is at least one subcarriers, and the subcarriers classified as a scalar with a single subcarrier (460-1,440-1) as indicated in Fig. 7A as an example, or as vector with at least two frequency domain subcarriers (460-8:460-9,440-1), or as a vector with at least two time domain subcarriers

(460-1,440-4:440-5), or at least two frequency domain subcarriers and at least two time domain subcarriers (460-8:460-9,440-12:440-13) to create as example two vectors, vector-A and vector-B; wherein the positions of single subcarrier classification in one stream do not match in frequency and time to a single subcarrier classification of the second stream, the positions of at least two frequency domain subcarriers classification in one stream do not match in frequency and time to two frequency domain subcarriers classification of the second stream, and the positions of at least two time domain sub- carriers classification in one stream do not match in frequency and time to two time domain subcarriers classification of the second stream.

[0043] In one of the example 20-2 based on Fig. 7A and classifications with least two

frequency domain subcarriers and at least two time domain subcarriers

(460-8:460-9,440-12:440-13), a first stream may use vector-A and vector-B each with two entries, while a second stream may use all the subcarrier in the said classification to create a four dimensional vector.

[0044] In a second example 20-2 as exemplified in Fig. 7B, a first data stream will use scalar pattern (classifications) to group subcarrier (460-1,440-1) and a second subcarrier (460-2,440-1) as two different groups, while a second data stream will create a group of subcarrier (460-1:460-2,440-1) such that the overlapping groupings of subcarriers for each stream are different to at least a second stream at the same subcarrier index and time domain index.

[0045] In another example of grouping 20-2, as exemplified in Fig. 7B, a first data stream will group subcarriers (460-5:460-6,440-7:440-8) as one group with two time domain groups, while a second data stream will group subcarriers (460-5:460-6,440-7:440-8) with two frequency domain groups such that the partially overlapping groupings of subcarriers for each stream do not overlap in grouping format (or scalar or vector patter) with at least a second stream.

[0046] According to the second aspect of this invention, there is provided a block or frame of OFDM symbols or symbols of a sub-bank filter, constituting at least two OFDM symbols, the OFDM operation of which can be done using FFT, IFFT or any kind of multi-band filtering with each band considered as a subcarrier; the subcarriers of which are grouped according to the first aspect of this invention; wherein the positions of single subcarrier classification (scalar) in one stream match in frequency and time to a single subcarrier classification (scalar) of the second stream, or the positions of at least two frequency domain subcarriers classification in one stream (vector) match in frequency and time to two frequency domain subcarriers classification (vector) of the second stream, or the positions of at least two time domain subcarriers classification (vector) in one stream match in both frequency and time to subcarriers classification (vector) of the second stream.

[0047] In one of the examples 20-2 of the second aspect as exemplified in Fig. 7B, a first data stream has a subcarrier grouping (460-1,440-1), while a second data stream will create a group of subcarrier (460-1,440-1) such that the groupings overlap.

[0048] According to a third aspect of this invention as illustrated in Fig. 8, there is provided a first processor 501 or a first program 501 that generates a sequence phases 502, a second processor that shifts the phases of modulated symbols on first subcarrier 1250 of a first stream from the subcarrier mapping processor 1208; wherein the stream of phases 502-1 that that are used to shift data in one of the subcarriers 1250 of a first stream 1247 is different from the stream of phases 502-2 that that are used to shift data in one a subcarriers 1252 of at least a second stream 1248, and the said at least one subcarrier 1252 may or may not corresponds in frequency band of the said at least one subcarrier 1250 of the first stream; and phase shifted data are processed in OFDM processor 1211, 1212, or preprocessed within 504 before processing in OFDM processor 1211, 1212.

[0049] According to a fourth aspect 42 of this invention as illustrated in Fig. 9, there is provided a first processor 511 or a first program 511 that generates a sequence of matrices 512, a second processor 514-2 that multiplies a matrix within the matrix stream 512 and a vector 514-1 of modulated symbols 1250 from the subcarrier mapping processor 1208; wherein the stream of matrices 512-1 that are used to multiply a vector created from modulated data 514-1 in at least two subcarriers in the frequency domain of a first stream 1247 is different from the stream of matrices 512-2 that that are used to multiply a vector created from modulated data 514-1 in at least two subcarriers in the frequency domain of at least a second stream 1248, and the said at least two subcarrier 514-1 from the first stream 1247, and at least a second stream 1248 may overlap according to the second aspect of this invention, or may not overlap according to the first aspect of this invention.

[0050] According to a fifth aspect 43 of this invention as illustrated in Fig.10, there is

provided a first processor 511 or a first program 511 that generates a sequence of matrices 512, a second processor 524-2 that converts serial modulated data 507-1 mapped on a subcarrier into parallel format, a third processor 514-2 that multiplies a matrix and a first vector 524-3 to create a second vector 524-4; wherein the stream of matrices 501-1 that that are used to multiply a vector 524-3 created from modulated data in at least two subcarriers in the time domain of a first stream, is different from the stream of matrices 512-2 that that are used to multiply a vector created from modulated data 524-3 in at least two subcarriers in the time domain of at least a second stream, and the said at least two subcarrier for generating the vectors 524-3 from the first stream 1247, and at least a second stream 1248 may overlap according to the second aspect of this invention, or may not overlap according to the first aspect of this invention.

[0051] According to a sixth aspect 44 of the present invention as illustrated in Fig.l 1,

provided is a section of communication transmitting system according to OFDM or multi-band scheme including a first processor 511 or a first program 511 that generates a sequence of matrices 512, a second processor that generates a sequence of phases, a third processor 524-2 that converts serial modulated data 507-1 mapped in a subcarrier into a parallel format, a fourth processor 514-2 multiplies a matrix and a vector created from 524-3 or 514-1 to create a second vector 524-4 or 514-3, a fifth processor that shifts the phases of modulated symbols 1251 from the subcarrier mapping processor 1208; wherein the stream of matrices 512-1 that that are used to multiply a vector created from modulated data 524-3 in at least two subcarriers in the time domain of a first stream, is different or same as a stream of matrices 512-2 that that are used to multiply a vector created from modulated data 514-1 in at least two subcarriers in the frequency domain of at least a second stream 1248; stream of phases 502-1 that that are used to shift data in one of the subcarriers 1251 of a first stream 1247, and a stream of matrices 512-2 that are used to multiply a vector 524-3 created from modulated data 1253 of subcarrier 1253 of the second stream 1248, corresponding to the subcarrier 1251 of the first stream, said vector 524-3 created with at least two subcarriers in the time domain of a first stream 1247, said at least two subcarrier used to create a vector 514-1 from the second stream 1248, may overlap according to the second aspect of this invention, or may not overlap according to the first aspect of this invention.

[0052] According to a seventh aspect 600 of the present invention as illustrated in Fig.12, provided is a section 2210 of communication receiving system according to OFDM or multi-band scheme, and according to signal transmitted in accordance with third aspect of the present invention; the said receiving system represented as multiple sources with source#l 2258 and source#2 2259, each source having at least one subcarrier 2254, 2256, corresponding to a multiple output system; the system including a first processor 501 for generating a sequence of phases, wherein each phase sequence is uniquely defined for a source or a corresponding sub-stream at the said transmitter, the system comprising: an inverse phase or conjugate phase, the inverse phase being applied to one or more similar subcarriers (subcarrier#l 604-1 of a source 2258 to subcarrier#N 604-N of at least one more source 2259) of multiple received signals, the inverse phase sequence corresponding to the target stream hence limiting the possible phases of the corresponding target source, and a combining unit controlled by an adaptive algorithm that combines multiple of at least two subcarriers in order to remove other sources or interfering signals which occupy the same frequency band or subcarrier, or the transmission time interval.

[0053] According to an eighth aspect of the present invention as illustrated in Fig.13,

provided is a section of communication receiving system according to OFDM or multi- band scheme, and according to signal transmitted in accordance with third aspect of the present invention; the said receiving system represented as multiple sources each of at least one subcarrier corresponding to a multiple output system; the system including a first processor for generating a sequence of phases, wherein each phase sequence is uniquely defined for a source or a stream at the said transmitter, the system

comprising: a combining unit controlled by an adaptive algorithm that combines multiple signals, and an inverse phase or conjugate phase, the inverse phase being applied to the output of the combiner, and together with the combiner and adaptive algorithm remove other sources or interfering signals which occupy the same frequency band or subcarrier, or the transmission time interval, and the algorithm also determines if data from the combiner 605 meets a desired criteria, where if the criteria is met the algorithms controls the buffer 607 to generate the desired output signal 608 of the target source and subcarrier.

[0054] According to ninth aspect 700 of the present invention as illustrated in Fig.14,

provided is a section 2210 of communication receiving system according to OFDM or multi-band scheme, and according to signal transmitted in accordance with fourth aspect of the present invention; the said receiving system represented as multiple sources with source#l 2258 and source#2 2259, each having at least two pairs of subcarrier that are used to generate at least the first vector 704-11, and a second vector 704-N1; wherein the system there is a first processor 511 for generating a sequence of matrices, with each matrix sequence being uniquely defined for a source or a stream at the said transmitter; the first processor further comprising: an inverse matrix generator, with the sequence inverse matrix 712 being applied to at least two pairs of subcarrier 704-11, 704-lN, and each pair from each source 2258, 2259 corresponding to the same subcarriers (704-11, 604-12), (704-N1, 604-N2) of each of the multiple received signals 2258; a second processor for multiplying a vector of two subcarriers; a third processor for combining same subcarriers generated from the second processor using weights that are generated by an adaptive algorithm in the fourth processor, further the algorithms controlling the output of a buffer based on the output of subcarrier that meets a set criteria. It is also possible to reverse the position of combiner and multiplication with matrix sequence as illustrated in Fig.14 A.

[0055] According to tenth aspect 700 of the present invention as illustrated in Fig.15,

provided is a section 2210 of communication receiving system according to OFDM or multi-band scheme, and according to signal transmitted in accordance with fifth aspect of the present invention; the said receiving system represented as multiple sources 2258, 2259, each having at least one subcarrier 744-1; wherein the system there is a first processor 744 that generates at least two pair of data (704-11, 704-12) from a subcarrier by serial to parallel conversion or any other method, second processor for generating a sequence of matrices, with each matrix sequence being uniquely defined for a source or a stream at the said transmitter; the second processor further comprising: an inverse matrix generator, with the sequence of inverse matrix 712 being applied to at least two pairs of sub-streams 704-11, 704-12, and each pair from each source 2258, 2259 corresponding to the same subcarrier 2254, 2256 of each of the multiple received signals 2258,2259; a third processor for multiplying a vector of two subcarriers; a forth processor for combining the same subcarriers generated from each of the sources 2258, 2259, using weights that are generated by an adaptive algorithm in a fifth processor, further the algorithm controlling the output of a buffer based on the output of subcarrier that meets a set criteria.

[0056] (First Embodiments)

As the first embodiment of the present invention, a MIMO system that has been configured as an OFDM based communications system is constituted by a transmitter 120 of Fig. 1A for transmitting at least one signal 102, a transmission medium 300 through which the at least one signal 103 are transmitted, and a receiver 200 for receiving signals from the said transmission medium, and then generate the original at least one signal 202 that were transmitted through the medium.

[0057] Fig. 2 shows the model 120 of an MIMO-OFDM system. Note that in this model 120, OFDM that is constituted of IFFT at the transmitter and FFT at the receiver has been used for illustration purposes. Further, it should be noted that MIMO system can be modeled in communications system where multiple transmitters are transmitting through the same channel. Thus, in this invention, it is not necessary that the transmitter should have multiple transmitting antennas. This will be obvious to a person who has expertise in this field. It should also be obvious that alterative filter banks could be used instead of IFFT and FFT, and therefore IFFT and FFT are only used for explanation purposes.

[0058] We also assume as an example that the transmitter model 120 transmits packets of data from at least one source. In case of multiple sources, some packets may be from a sound, others from text, digital data from the internet, and other packets from any other source that generates signals. All these packets are scheduled in MAC according to their constraints using a preprocessing unit 1201. In Fig. 2, the preprocessor 1201 distribute data to be processed in a certain format. As an example, one of the blocks of data 1241 is scrambled using a scrambling code. A second block 1241-2 may be processed in a different format, but in all the processing of blocks of data, there is always provided an OFDM operation 1211 followed by addition of a cyclic prefix.

[0059] Now considering the at least one block of data 1241 that is constituted with bits, either bit "1" or bit "0", the scrambler may scramble different sections of the block of data 1241 using different scrambling codes. Such an approach is effective when different systems share the communication medium 300, and channel coder is used. After scrambling the data to generate scrambled bits 1242, the block could be divided into at least one sub-block, and to each sub-block, cyclic redundancy check (CRC) bits could be added in processing unit 1203, to generate at least one sub-block 1243 with CRC bits.

[0060] For explanation purposes, this invention considers there are several sub-blocks 1243 generated by CRC processing unit 1203. These sub-blocks 1243 could be joined to create larger blocks, or they could be broken down further into smaller blocks. Further, additional bits that do not bear information could be added, or some bits could be repeated to create one or several code blocks 1244. All these operations could be done within the channel coding preprocessing unit 1204.

[0061] Each of the code blocks could then be channel coded in the channel coding unit 1205 to generate channel coded blocks of data 1245. Channel coding could be as simple as repeating bits. In one of the examples, each bit within a code block 1244 could be repeated. Alternatively, the code blocks 1244 could be coded using convolution coding (CC) or any other channel coding method.

[0062] Channel coded code blocks 1245 could further be processed in the channel coding post-processing unit 1206 by scrambling the bits, removing certain bits so that the coded code blocks are of a specified size. This process of adjusting the sizes of the block is generally referred to as rate matching. Interleaving of the channel coded code blocks 1245 could also be done. Channel coding post-processing unit 1206 generates bits that could then be mapped into at least one layer of a multiple-input multiple- output (MIMO) system. Data mapped on a layer shall be called a stream, and thus in Fig. 2 there are two streams clearly indicated as stream* 1 1247 and stream#2 1248. Note however that division to multiple streams in not a necessity, as a second stream could be generated from an independent transmitting terminal. It is also possible that at least one more blocks of data 1241-2 from the preprocessing unit 1201, having been processed in a similar manner to the first blocks of data 1241 from the preprocessing unit 1201 could be used to generate a second stream. Mapping of processed blocks 1246 to different layers or streams of a MIMO system is done using a channel sublayer mapping unit 1207 to generate at least one stream of data 1247. In a MIMO systems, there are at least two streams, stream#l 1247 and stream#2 1248.

[0063] In a MIMO-OFDM system, the at least two streams are each modulated, and

modulated data mapped to different physical or logical indices of an IFFT subcarriers using a subcarrier mapping unit 1208 to generate a number of subcarrier modulated data. Fig. 2 shows two subcarriers, subcarrier#l 1250 and subcarrier#2 1251. In a general case, corresponding subcarriers from different streams maybe precoded in unit 1210 using a precoding matrix, or the subcarrier modulated data could be tagged using tagging filter 120-1, and an optional post tagging filter (TF) processing unit 120-2 that includes at least an inteleaver or a scrambler. In this invention, and in one of the modes of implementation, the TF processing 120-3 that has been indicated within Fig. 6 is replaced by an ID assigning unit 520 as indicated in Fig.10.

[0064] The ID assigning unit assigns or groups subcarriers along the time domain into

groups comprising of at least one subcarrier (460-1, 440-1) or at least two subcarriers (460-1,440-4:440-5) as shown in Fig. 7. ID assigning unit 520 achieves grouping into at least two subcarriers using a serial-to-parallel converter 524-2 that converts each stream of data on a subcarrier into parallel data 524-3, as shown in Fig.10. Further, the ID assigning unit 520 has a matrix sequence generator 511 that generates a sequence of matrices. Corresponding subcarriers, subcarrier#l 1250 and subcarrier#2 1250 from different streams, stream#l 1247 and stream#2, respectively, are assigned unique matrix ID. Modulated data 1250 that has been converted into parallel modulated data 524-3 can be represented as a vector x_m,i(k,k+l), where m is an index of a stream, where 1 is an index of a subcarrier, and as illustrated k and (k+1) are values indicating respectively the k* and (k+l)^th OFDM symbols. The matrix ID, G_{m l}(k,k+1) corresponds to vector x_{m l}(k,k+l). The ID assigning unit 520 is also provided with a matrix multiplier that multiplies vector x_m>,(k,k+l) 542-3 and matrix ID, G_mJ(k,k+l) 512 as indicated in Eq.(3) to generate ID assigned vectors x~_mj(k,k+l) 524-4.

[Math.3]

x _mil (k,k+ 1 ) = G m_fi (k,k+ 1 ) x_m(i (k_f k+ 1 ) - - - (3)

[0065] Note that the first matrix sequence 512-1 shall be different from a second matrix sequence 512-2 so long as there is at least one time interval when G_{m [}(k,k+1) and G m_+m'a(k,k+l) are different, where m' not equal 0 has been added to m in order to indicate that index of streams of these two matrices are different. Also, a sequence of matrix (MSequence) shall be represented as indicated in Eq.(4).

[Math.4]

MSequence_m ={G_mfl(k,k+ 1) G_mjl(k+2,k+3) G_m,i (k+4,k+5) G_m,i(k+6,k+7) -^■■}

^■-^■(4)

[0066] The corresponding vectors sequence (VSequence) 524-3 for the case of Eq.(4) shall be represented as indicated in Eq.(5).

[Math.5]

VSequence_m ={x_m(L(k,k+ 1 ) x_m,_L (k+2,k+3) x_m,i (k+4,k+5) x_m,i(k+6,k+7)^■■■}

^■■■ (5)

[0067] While Eq.(4) and Eq.(5) indicates gradually increasing time indices k, it also possible for matrix sequence generator 511 to assign time intervals in steps as indicated in Eq.(6), for the case of a two-step time interval, and the order of each matrix could also be changed.

[Math.6]

MSequence^ ={G_{m l}(k,k+2) G_m,i (k+ 1,k+3) G_m,i (k+4,k+6) G_m,i (k+5,k+7) -^■■}

^■■■ (6)

[0068] The ID assigning unit is also provided with a parallel-to-serial converter(PS) 524-5 that converts modulated data with matrix ID 524-4 into serial data 1254-2 for mapping to subcarriers of IFFT in an OFDM using an OFDM&CP unit 1211 to generate an OFDM symbol 1258. OFDM can also be considered as sub-band filtering, and in case of a single band (or a single carrier), a general term of a filter shall be used.

[0069] Also, as indicated in Fig. 2 the OFDM symbols 1258 could be further processed in a post-OFDM processing unit 1213 before transmission through a medium 300. The post-OFDM processing unit 1213 could include operations such as digital to analogue converter, amplifier, band-limiting filter among other possibilities, in order to generate signal 103 for transmission through the medium 300.

[0070] Fig.4 shows one of the possible methods of implementing the receiver of the current invention where there is provided at least one receiving unit for receiving at least one signal 203 from the communication medium. It is also possible to have a second receiving unit as indicated in Fig.4 to receive a second signal 205 from the medium. Each of these signals are processed using a pre-OFDM processing unit 2213 that filters received signal, amplifies received signal, performs synchronization and analogue to digital conversion.

[0071] Pre-OFDM processed signal or data 2258 are further processed using an inverse

OFDM processing unit 2211 that removes cyclic prefix and implements FFT operation to generate data 2254 associated with different subcarriers. If a single carrier is used, the inverse OFDM could be removed resulting in at least one subcarrier 2254 (in general). With at least two received signals, signal#l 203 and signal#2 205, there are corresponding subcarriers, such as subcarrier 2254 and subcarrier 2256, which are used in channel estimation and equalization unit 2210. In one example of the current invention, channel estimation and equalization unit 2210 is implemented as indicated in Fig.15, where there is provided serial-to-parallel (SP) conversion unit 744, that converts serial data to parallel data (or a vector) 704-11 in same manner as the SP unit 524-4 of the transmitter, and whose details have been provided in Eq.(5).

[0072] Further, there is provided a matrix sequence generator 511 that generates a sequence of matrices 712 in similar manner as the transmitter matrices 512. Assuming the data vector 704-11 is represented as y (k,k+l), then there is provided a matrix multiplier unit (ITM-1) 714-2 for each corresponding subcarriers 2254 and 2256, that multiplies at least one of the vectors y_n>1(k,k+l) with an inverse of the matrix generated from the matrix sequence 712. In this symbol, y_{n !}(k,k+l) , n is an index of a stream, such as stream#l 2258 at the receiver. This sequence of matrix 712 correspond to say the sequence of matrix 512-1 that was used as an ID 512-1 on a target stream at the transmitter, such as stream#l 1247. As an example, the inverse matrix G(inverse)_mjl (k,k+l) could be generated as shown in Eq.(7) or Eq.(8) for the case of G_m,,(k,k+1) of the m* target stream.

[Math.7]

G_m(l (k,k+ 1 ) = {G _m,_L (k,k+ D} ^{"1 ■■■} (?)

[Math.8]

G _m|l(k_fk+ 1 ) = {G _m,i(k,k+ 1) Gfc(k,k+ 1)}-¹ G ¾k+ 1) . . . (₈) [0073] Multiplying matrix inverse G(inverse)_m,i(k,k+1) with vector y„,i(k,k+l) 714-11 generates vector y_{n m>1}(k,k+l) 704-21, which is converted to serial data y_n,_m,i(k) 705-1 using a parallel-to-serial converter(PS) 754. There are multiple serial data generated, where in this mode of implementation N serial data, data#l 705-1 to data#N 705-N are generated, where N is two for the two received streams (stream#l 2258 and stream#2 2259). These serial data y_n,m,,(k) (data#l 705-1 to data#N 705-N) for (n=l,..,N) can be represented as a vector as shown in Eq.(9).

[Math.9]

[0074] The channel estimation and equalization unit 2210 is also provided with an adaptive algorithm unit 706 that generates a vector h^A _{n l}(k) 706-1 that is used to combine the serial data vector y^A _m,i(k) (data#l 705-1 to data#M 705-N) into a scalar quantity 707-1. The adaptive algorithm unit 706 monitors the scalar quantity 707-1 to meet a certain criteria, such as regenerating the original structure of modulated data 1250 at the transmitter such as BPSK, QPSK or 16QAM. Further, the scalar data 707-1 are buffered in buffering unit 707 that is controlled by the adaptive algorithm unit 706 using a control signal 706-2. Once the scalar data has met the desired criteria, those data in the buffer that met the criteria are released as equalized data 708 that corresponds to the target data on subcarrier 1250, or alternatively data 2250. Now using a similar process 710-1 on a second subcarrier (process 710-2) it is possible to generate a second subcarrier 2251 that corresponds to subcarrier 1251 at the transmitter.

[0075] Equalized data from the subcarrier are demapped from subcarrier indices using a subcarrier de-mapping unit 2208 that also generates soft bits 2247 for the first stream, and other soft bits 2248 for a second stream as shown in Fig.4. The at least two streams removed from their specific layers are combined into a single stream soft bits 2246 using a channel sublayer de-mapping unit 2207. The channel sublayer de-mapped data 2246 are processed by a channel predecoding unit 2206 that may include operations such as adding bits that were pruned off during rate matching at the transmitter, a de- interleaver operation or a de-scrambler, division of the stream 2246 into block, in order to generate coded code blocks 2245 for channel decoding in the channel decoding unit 2205.

[0076] The channel decoding unit 2205 generates received code blocks of data bits that could be divided into smaller blocks, or combined into larger blocks 2243 for checking error during transmission by using CRC bit removal and error checking unit 2203. The bits without error 2242 are descrambled in a descrambling unit 2202 to generate data for post-processing in the post-processing unit 2201, and thus receiving originally transmitter data, data#l 102, data#2 104, respectively as data#l 202 and data#2 204.

[0077] (Second Embodiment)

In the second embodiment of the present invention, data after subcarrier mapping 1250 are processed at the receiver as indicated in Fig. 8, where the unit 520 for assigning ID to data streams 1247 consists of a phase sequence generator 501 that generates a sequence of phases that are unique to corresponding subcarriers of different streams. Thus, if subcarrier#l 1250 of the first stream 1247, and a corresponding subcarrier#2 1252 of the second stream 1248 are considered, then these two subcarrier shall have a sequence of phases (PSequences) that are different, considering that they using the same scalar grouping pattern as illustrated in Fig. 7.

[0078] Note that the first phase sequence 502-1 shall be different from a second matrix

sequence 502-2 so long as there is at least one time interval k when the phases values 502-1 and 502-2 are different. Also, a sequence of phases shall be represented as indicated in Eq.(10).

[Math.10]

PSequence_m ={P_m,_L (k) P_m,i (k+ 1 ) P_m,i(k+2) P _m,i(k+ 3) -^{■ ■}} ^■■■ ( 10)

In Eq.(10), P_m,,(k) is given Eq.(l l).

[Math.11]

[0079] Further, Phi_m ,(k) is a random phase generated using a kind of known random number generator, or it could be non-random sequence, either of which it takes a value between 0 and 2pi. Consequently, Phi_nJ(k), Phi_m+m ,i(k) for some value of time index k, and values of stream indices m and m+m', where m' is not equal 0.

[0080] The unit 520 for assigning ID to data streams 1247 also consists of a multiplier or a rotator that multiplies stream of data on subcarrier 1250 associated with stream#m using the PSequence_mto generate stream 1254-2 that is then mapped to a subcarrier of an OFDM. Thereafter, OFDM&CP unit 1211 and post-OFDM processing unit operates as explained earlier. In this mode of implementation, the subcarriers can be considered as having been grouped into single subcarrier, such as subcarrier (460-1,440-1) indicated in Fig. 7A and Fig. 7B.

[0081] At the receiver, the channel estimation and equalization unit 2210 is implemented as indicated in Fig.12, where there is a phase sequence generator 501 that generates a sequence of phases (PSequences) 612 in similar manner as the transmitter phases 502. There is also provided a phase multiplier unit (ITP- 1 ) 604 for each corresponding sub- carriers 2254 and 2256, that multiplies at least one of the data on subcarrier with an inverse of the phase generated from the phase sequence 612. If m is an index of the target transmitted stream, the sequence of phases correspond to the sequence of phases 612-1 that was used as an ID 502-1 on a target stream at the transmitter, such as stream#l 1247. As an example, the inverse phase

P^"m.i(k) could be generated as shown in Eq.(12).

[Math.12]

[0082] Signal after phase multiplier unit (ITP-1) results in multiple serial data generated, where is this mode of implementation, there are N serial data, data#l 605-1 to data#N 605-N. These serial data y _m,,(k) (data#l 605-1 to data#N 605-N) for (n=l...N) can be represented as a vector as shown in Eq.(9).

The channel estimation and equalization unit 2210 is also provided with an adaptive algorithm unit 606 that generates a vector h^A _{n l}(k) 606-1 that is used to combine the serial data vector y^A„,i(k) (data#l 605-1 to data#M 605-M) into a scalar quantity 607-1. The adaptive algorithm unit 606 monitors the scalar quantity 607-1 to meet a certain criteria, such as regenerating the original structure of modulated data 1250 at the transmitter. Further, the scalar data 607-1 are buffered in buffering unit 607 that is controlled by the adaptive algorithm unit 606 using a control signal 606-2. Once the scalar data has met the desired criteria, those data in the buffer that met the criteria are released as equalized data 608 that corresponds to the target data on subcarrier 1250, or alternatively data 2250. Now using a similar process on 600-2 it is possible to get for a second subcarrier 2251 that corresponds to subcarrier 1251 at the transmitter.

[0083] The channel decoding unit 2210 can also be implemented by interchanging the

position of the combiner 605 and the phase multiplier unit (ITP-1) 604 as indicated in Fig.13. In this case, the serial data vector y^A _nJ(k) (data#l 604-1 to data#N 604-N) is combined with a weight vector h^A _n,i(k) 616-1 and the output of phase multiplier unit (ITP-1) 616-4 monitored by algorithm unit 606-21 to meet the desired criteria.

[0084] (Third Embodiment)

In the third embodiment of the present invention, data after subcarrier mapping 1250 are processed at the receiver as indicated in Fig. 9, where the unit for assigning ID 520 to data streams 1247 consists of grouping together at least two subcarriers

(460-8:460-9,440-1) along the frequency domain as indicated in Fig. 7. Note that these grouping could be based on logical or physical subcarrier index. The grouping of at least two subcarriers creates a vector sequence 514-1. Further as in the first embodiment of the present invention, there is provided a matrix sequence generator 511 that generates a sequence of matrices 512 for the at least the first stream (matrix#l 512-1), and for the at least the second stream (matrix#2 512-2) if a second stream is needed at the receiver.

[0085] Also, the unit for assigning ID 520 to data streams 1247 consists of a matrix

multiplier unit 514-2 that multiplies the vector sequence 514-1 with the matrix sequence 512 that has been generated in the same was as indicated in the first embodiment of the present invention using Eq.(4), Eq.(5) and Eq.(6). The matrix multiplier unit 514-2 generates a second vector sequence 514-3 that is obtained from the multiplication of the first vector sequence 514-1 and the matrix sequence 512-1. These second vector sequence 514-3 are then mapped to the subcarriers of OFDM and processed for transmission as explained in the first embodiment of the present invention.

[0086] At the receiver, the channel estimation and equalization unit 2210 is implemented as indicated in Fig.14, where there is a matrix sequence generator 511 that generates a sequence of matrices (MSequences) 712 in similar manner as the transmitter's sequence of matrices generator 511. Data from the subcarriers 2254 are grouped to create vectors 704-11 from the first received data 2258, and vectors 704- IN for the Nth received data 2259. Each of these N vectors y (k,k+l), for (n=l,...,N), is multiplied with an inverse of the matrix generated from the matrix sequence 712. In this symbol, y (k,k+l) , m is an index of the target transmitted stream as indicated in the first embodiment of the present invention. This sequence of matrix correspond to say the sequence of matrix 712-1 that was used as an ID 512-1 on a target stream at the transmitter, such as stream#l 1247.

[0087] Multiplying matrix inverse vector y_n (k,k+l) 704-11 generates serial data y^A _n,_{m l}(k) (data#l 705-1 to data#M 705-M) for (m=l...N), and which can be represented as a vector as shown in Eq.(9).

[0088] The channel estimation and equalization unit 2210 is also provided with an adaptive algorithm unit 706, a combining unit 705 and a buffer 707, that operates as indicated in the first embodiment of the present invention.

[0089] The position of the combiner 705 and matrix multiplier unit could also be reversed as shown in Fig.15, such that corresponding subcarriers from different received streams are first combined into a single subcarrier using a weight combiner 706-1 that uses weights that have been generated by adaptive algorithm 706. All the resulting sub- carriers, such as the first subcarrier 715-11 and the second subcarrier 715-12 will be from the target transmitted stream. The at least two subcarriers, first subcarrier 715-11 and the second subcarrier 715-12 are multiplied with matrix inverse obtained from a sequence of matrices that has been generated by matrix sequence generator 511 in order to generate outputs 717-1 that are monitored by adaptive algorithm 706 in order to meet the desired criteria.

[0090] Now, three embodiment of the present invention have been provided, but it should be obvious to someone familiar with this kind of a system that there are alternative modes of implementation as illustrated in Fig.11 for the transmitter that utilizes a combination of at least two of the three embodiment of the present invention. In one of the example, data for first subcarrier 1250 of the first stream 1247 are processed according to the first embodiment of the present invention at both the transmitter and receiver, using vector classification time domain. Data for the second subcarrier 1251 of the first stream 1247 are processed using scalar classification according to the second embodiment of the present invention at both the transmitter and receiver. Data for the group of subcarrier (vector) 514-1 of the second stream 1247 are processed according to the third embodiment of the present invention at both the transmitter and receiver, and data on the second subcarrier 1253 of the second stream 1247 that corresponds to second subcarrier 1251 of the first stream 1247, are processed according to the first embodiment of the present invention at both the transmitter and receiver.

[0091] Also as was indicated in second embodiment of the present invention, it is possible to interchange the order of processing at channel estimation and equalization unit 2210, where multiplication with inverse matrix sequences is done after the combiner unit. Also, multiplication with inverse phase ID could be done after the combiner unit.

[0092] In a more general way, this invention has a transmitter that classifies subcarriers into either scalar or vector. Subcarriers classified as scalar are multiplied with a phase rotator, while subcarriers classified as vectors are multiplied matrices. Further, the mode of classifications can be used as an ID, such that classification as vectors in time domain and classification of vectors in frequency domain represents two IDs. Also, classification using vectors in a diagonal format as indicated in Fig. 7A can also create another pattern. Additional pattern can be created by one diagonal vector, such as vector-A in Fig. 7, and two scalar classification within the first region (460-8,460-12) and a second region (460-9, 460-13). It is also possible to create a four dimensional vector using all the subcarriers within the grouping defined in Fig. 7's two dimensional region (460-8:460-9, 460-12:460-13). Thus, the combination of classifications, sequence of phase rotators, and sequence matrices provide a combination for granting ID to transmitting modules.

[0093] (Other Embodiments)

The information processing procedure corresponding to the client or customer need not always be owned by only the client who has created it, and may be made open to other clients under predetermined conditions. In this case as well, access to the result of information processing is preferably permitted for only authenticated clients.

[0094] While the present invention has been described with reference to embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

[0095] The present invention is applicable to a system including a plurality of devices or a single apparatus. The present invention is also applicable even when a control program for implementing the functions of the embodiments is supplied to the system or apparatus directly or from a remote site. Hence, the present invention also incorporates the control program installed in a computer to implement the functions of the present invention on the computer, a medium storing the control program, and a WWW (World Wide Web) server that causes a user to download the control program.

[0096] (Other exemplary embodiments)

Some or all of the above-described embodiments can also be described as in the following further exemplary embodiments, but are not limited to the followings.

(Further exemplary embodiment 1)

A communications system comprising:

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

wherein said receiver comprises:

(Further exemplary embodiment 2)

A communications system comprising: a transmitter for transmitting at least one stream of signals through a communication channel or a communication medium that is being shared with at least another transmitter another stream; and

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

wherein said receiver comprises:

said receiver, in a first step, multiplies said received major groups from at least one receiving module with a sequence comprising complex conjugate of said complex exponent of said phases to generate modified sub-streams and, in a second step, combines with weighting factor, said modified sub-streams having the same sub- stream index and having been obtained from at least one of the receiving modules. (Further exemplary embodiment 3)

The communications system according to exemplary embodiment 2, wherein said receiver comprises:

said receiver, in a first setep, combines with weighting factor, said at least one received sub-streams having the same sub-stream index and having been obtained from at least one of the receiving modules to generate a combined signal for each sub-stream and, in a second step, multiplies said received major groups of the combined signal are multiplied with a sequence comprising complex conjugate of said complex exponent of said phases to generate modified sub-streams.

(Further exemplary embodiment 4)

The communications system according to exemplary embodiment 1 or 2 or 3, wherein said generation unit of said receiver generates a plurality of sequence of phases for each sub-stream corresponding to sequence of phases of similar sub-stream at the transmitter of the signal that is targeted for error free reception at the receiver.

(Further exemplary embodiment 5)

A communications system comprising:

a transmitter for transmitting at least one stream of signals through a communication channel or a communication medium that is being shared with at least another transmitter or another atream; and

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

wherein said receiver comprises:

said receiver, in a first step, multiplies said received frequency domain vector within major groups from at least one receiving module with a sequence comprising inverses of said sequence of matrices to generate modified sub-streams and, in a second step, combines with weighting factor, said modified sub-streams having the same sub- stream index and having been obtained from at least one of the receiving modules. (Further exemplary embodiment 6)

The communication system according to exemplary embodiment 5, wherein said receiver comprises:

a classifying unity that classifies received sub-streams from at least one receiving module into groups and major groups using the format of the transmitter to create a frequency domain vector; and

said receiver, in a first step, combines with weighting factor, said at least one received sub-streams having the same sub-stream index and having been obtained from at least one of the receiving modules to generate a combined signal for each sub-stream and, in a second step, multiplies said combined signal for each sub-stream are grouped in accordance with the same format of the target stream that was transmitted, said grouping creating a frequency domain vector that is major groups of the combined signal, with a sequence comprising inverses of said sequence of matrices associated with the group to generate modified sub-streams.

(Further exemplary embodiment 7)

The communications system according to exemplary embodiment 5 or 6, wherein the sequence of matrices comprises at least one orthogonal matrix.

(Further exemplary embodiment 8)

The communications system according to exemplary embodiment 1 or 5 or 6, wherein said generation unit generates a plurality of sequence of matrices for each sub-stream of the at least two sub-stream corresponding to sequence of matrices of similar sub- streams at the transmitter of the signal that is targeted for error free reception.

(Further exemplary embodiment 9)

A communications system comprising:

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

a classifying unit that classifies data into a first set of groups with each said first set of groups including at least two data samples, said a first set of groups having at one sub- stream index and at least two time domain indices to create a time domain vector, and further creating a major group that includes at least one of said first set of groups with same sub-stream index; and

a processing unit processes said grouped data by creating pre-determined random matrices having at least two time domain indices, using said matrices for each of said least two time domain indices to generate a sequence of matrices having same sub- carrier index as the major group, resulting said sequence of matrices being unique from at least a second sequence of matrices of a second major group of at least a second stream having the same said one sub-stream index as the first stream's sub-stream index, said second stream sharing the same channel as said first stream, using said sequence of matrices having said at least two time domain indices to multiply said frequency domain vector, generating a matrix-modified at sub-stream of data, and wherein said receiver comprises:

a classifying unit that classifies received sub-streams from at least one receiving module into a first set of groups and major groups using the format of the transmitter to create a time domain vector; and a generation unit that generates a sequence of matrices similar to the transmitter using pre-determined random matrices, and

(Further exemplary embodiment 10)

The communication system according to exemplary embodiment 9, wherein said receiver comprises:

a classifying unit that classifies received sub-streams from at least one receiving module into groups and major groups using the format of the transmitter; and a generation unit that generates a sequence of matrices similar to the transmitter using pre-determined random matrices, and

said receiver, in a first step, combines with weighting factor, said at least one received sub-streams having the same sub-stream index and having been obtained from at least one of the receiving modules to generate a combined signal for each sub-stream and, in a second step, groups said combined signal for each sub-stream in accordance with the same format of the target stream that was transmitted, said grouping creating a time domain vector in the major groups of the combined signal which are then multiplied with a sequence comprising inverses of said sequence of matrices associated with the group to generate modified sub-streams.

(Further exemplary embodiment 11)

The communications system according to exemplary embodiment 9 or 10 wherein the sequence of matrices comprises at least one orthogonal matrix.

(Further exemplary embodiment 12)

The communications system according to exemplary embodiment 9 or 10, wherein said generation unit of said receiver generates a plurality of sequence of matrices for each sub-stream of the at least one sub-stream corresponding to sequence of matrices of similar sub-stream at the transmitter of the signal that is targeted for error free reception at the receiver.

(Further exemplary embodiment 13)

A communications system comprising:

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

a classifying unit that classifies data on two dimensional space of sub-stream domain and time domain into groups using a combination of at least two of methods of creating groups according to claim 1 or 4 or 8, processing the sections of said two dimensional space according to grouping format such that section of said map grouped according to claim 1 are processed according to claim 1 , section of said map grouped according to claim 4 are processed according to claim 4, and section of said map grouped according to claim 8 are processed according to claim 8.

wherein said receiver comprises:

(Further exemplary embodiment 14)

The communications system according to any one of exemplary embodiments 1-13, wherein the sub-stream is changed to subcarrier, the sub-dimention is changed to subcarrier dimention or frequency dimention, and the sub-stream index is changed to subcarrier index or frequency domain index.

(Further exemplary embodiment 15)

A transmitter for transmitting at least one stream of signals through a communication channel or a communication medium that is being shared with at least another transmitter or another stream,

wherein said transmitter comprises:

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

(Further exemplary embodiment 16)

wherein said transmitter comprises:

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

a processing unit that processes said grouped data by creating pre-determined random matrices, using said matrices for each time index to generate a sequence of matrices having a time domain length equaling time domain length of said major group, resulting said sequence of matrices being unique from at least a second sequence of matrices of a second major group of at least a second stream having the same said two sub-stream indices as the first stream's two sub-stream indices, said second stream sharing the same channel as said first stream, using said sequence of matrices having sajd at least two sub-stream indices to multiply said frequency domain vector, generating a matrix-modified at least two sub-stream of data.

(Further exemplary embodiment 17)

The transmitter according to exemplary embodiment 16 wherein the sequence of matrices comprises at least one orthogonal matrix.

(Further exemplary embodiment 18) A transmitter for transmitting at least one stream of signals through a communication channel or a communication medium that is being shared with at least another transmitter or another stream,

wherein said transmitter comprises:

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

a classifying unit that classifies data into a first set of groups with each said first set of groups including at least two data samples, said first set of groups having at one sub- stream index and at least two time domain indices to create a time domain vector, and further creating a major group that includes at least one of said first set of groups with same sub-stream index; and

a processing unit that processes said grouped data by creating pre-determined random matrices having at least two time domain indices, using said matrices for each of said least two time domain indices to generate a sequence of matrices having same sub- carrier index as the major group, resulting said sequence of matrices being unique from at least a second sequence of matrices of a second major group of at least a second stream having the same said one sub-stream index as the first stream's sub-stream index, said second stream sharing the same channel as said first stream, using said sequence of matrices having said at least two time domain indices to multiply said frequency domain vector, generating a matrix-modified at sub-stream of data.

(Further exemplary embodiment 19)

The transmitter according to exemplary embodiment 18 wherein the sequence of matrices comprises at least one orthogonal matrix.

(Further exemplary embodiment 20)

wherein said transmitter comprises:

a pre-processing unit that pre-processes said sub-streams; and

wherein said pre-processing unit comprises:

a classifying unit that classifies data on two dimensional space of sub-stream domain and time domain into groups using a combination of at least two of methods of creating groups according to exemplary embodiment 2 or 5 or 9, processing the sections of said two dimensional space according to grouping format such that section of said map grouped according to exemplary embodiment 2 are processed according to exemplary embodiment 2, section of said map grouped according to exemplary embodiment 5 are processed according to claim 5, and section of said map grouped according to exemplary embodiment 9 are processed according to exemplary embodiment 9.

(Further exemplary embodiment 21)

The communications system according to any one of exemplary embodiments 15-20, wherein the sub-stream is changed to subcarrier, the sub-dimention is changed to subcarrier dimention or frequency dimention, and the sub-stream index is changed to subcarrier index or frequency domain index.

Claims

[Claim 1] A communications system comprising:

a transmitter for transmitting at least one stream of signals through a communication channel or a communication medium that is being shared with at least another transmitter or another stream; and a receiver for receiving said at least one stream of signals from said transmitter,

wherein said transmitter comprises:

a divider that divides said at least one stream into at least one sub- stream to create a two dimensional map of data with sub-stream dimension having a sub-stream index and a time dimension having a time domain index;

a pre-processing unit that pre-processes said sub-streams; and a post-processing unit that post-processes said pre-processed sub- streams using at least a filter,

wherein said pre-processing unit comprises:

wherein said receiver comprises:

a classifying unit that classifies received sub-streams from at least one receiving module using the same classification as the target stream of the transmitter; and

at least one of a generation unit that generates a sequence of phases for multiplying scalar groups, and a creation unit that creates matrices for multiplying with the vector groups.

[Claim 2] A communications system comprising:

a transmitter for transmitting at least one stream of signals through a communication channel or a communication medium that is being shared with at least another transmitter another stream; and a receiver for receiving said at least one stream of signals from said transmitter,

wherein said transmitter comprises:

wherein said pre-processing unit comprises:

a classifying unit that classifies data into groups by including only one data sample in each of a first set of groups within which there is only one sub-stream index and one time domain index, and further creating a major group that includes at least two of said first set of groups with said first set of groups in the major group having same sub-stream index; and

a processing unit that processes said grouped data by creating a sequence of pre-determined random phases having values within the range of zero and mathematical symbol 2pi, using said phases to generate a sequence of length equaling time domain index of said major group, with the resulting sequence being unique from at least a second major group of at least a second stream having the same sub-stream index as the first stream, and sharing the same channel as said first stream, using complex exponent of said sequence of phases to multiply and rotate phases of said data within said major group with same sub- stream index, and

wherein said receiver comprises:

a classifying unit that classifies received sub-streams from at least one receiving module into groups and major groups using the format of the transmitter; and

a generation unit that generates a sequence of phases similar to the transmitter using pre-determined random phases having values within the range of zero and mathematical symbol 2pi, and

said receiver, in a first step, multiplies said received major groups from at least one receiving module with a sequence comprising complex conjugate of said complex exponent of said phases to generate modified sub-streams and, in a second step, combines with weighting factor, said modified sub-streams having the same sub-stream index and having been obtained from at least one of the receiving modules. [Claim 3] The communications system according to claim 2, wherein said

receiver comprises:

said receiver, in a first step, combines with weighting factor, said at least one received sub-streams having the same sub-stream index and having been obtained from at least one of the receiving modules to generate a combined signal for each sub-stream and, in a second step, multiplies said received major groups of the combined signal are multiplied with a sequence comprising complex conjugate of said complex exponent of said phases to generate modified sub-streams. [Claim 4] A communications system comprising:

wherein said transmitter comprises:

a divider that divides said at least one stream into at least two sub- stream to create a two dimensional map of data with sub-stream dimension having a sub-stream index and a time dimension having a time domain index;

wherein said pre-processing unit comprises:

a classifying unit that classifies data into a first set of groups with each said first set of groups including at least two data samples, said first set of groups each having at least two sub-stream indices and one time domain index to create a frequency domain vector, and further creating a major group that includes at least two of said first set of groups with all the groups in the major group having the same at least two sub- stream index; and

a processing unit that processes said grouped data by creating predetermined random matrices, using said matrices for each time index to generate a sequence of matrices having a time domain length equaling time domain length of said major group, resulting said sequence of matrices being unique from at least a second sequence of matrices of a second major group of at least a second stream having the same said two sub-stream indices as the first stream's two sub-stream indices, said second stream sharing the same channel as said first stream, using said sequence of matrices having said at least two sub-stream indices to multiply said frequency domain vector, generating a matrix-modified at least two sub-stream of data with at least two indices of sub-stream and wherein said receiver comprises:

a classifying unity that classifies received sub-streams from at least one receiving module into a first set of groups and major groups using the format of the transmitter to create a frequency domain vector; and a generation unit that generates a sequence of matrices similar to the transmitter using pre-determined random matrices, and

said receiver, in a first step, multiplies said received frequency domain vector within major groups from at least one receiving module with a sequence comprising inverses of said sequence of matrices to generate modified sub-streams and, in a second step, combines with weighting factor, said modified sub-streams having the same sub-stream index and having been obtained from at least one of the receiving modules. [Claim 5] A communications system comprising:

wherein said transmitter comprises:

wherein said pre-processing unit comprises:

a classifying unit that classifies data into a first set of groups with each said first set of groups including at least two data samples, said a first set of groups having at one sub-stream index and at least two time domain indices to create a time domain vector, and further creating a major group that includes at least one of said first set of groups with same sub-stream index; and

a processing unit processes said grouped data by creating predetermined random matrices having at least two time domain indices, using said matrices for each of said least two time domain indices to generate a sequence of matrices having same sub-carrier index as the major group, resulting said sequence of matrices being unique from at least a second sequence of matrices of a second major group of at least a second stream having the same said one sub-stream index as the first stream's sub-stream index, said second stream sharing the same channel as said first stream, using said sequence of matrices having said at least two time domain indices to multiply said frequency domain vector, generating a matrix-modified at sub-stream of data, and

wherein said receiver comprises:

said receiver, in a first step, multiples said received time domain vector within major groups from at least one receiving module with a sequence comprising inverses of said sequence of matrices to generate modified sub-streams and, in a second step, combines with weighting factor, said modified sub-streams having the same sub-stream index and having been obtained from at least one of the receiving modules. [Claim 6] A communications system comprising:

a receiver for receiving said at least one stream of signals from said transmitter,

wherein said transmitter comprises:

a pre-processing unit that pre-processes said sub-streams; and a post-processing unit that post-processes said pre-processed sub- streams using at least a filter, wherein said pre-processing unit comprises:

a classifying unit that classifies data on two dimensional space of sub- stream domain and time domain into groups using a combination of at least two of methods of creating groups according to claim 1, processing the sections of said two dimensional space according to grouping format such that section of said map grouped according to claim 1 are processed according to claim 1,

wherein said receiver comprises:

wherein said transmitter comprises:

wherein said pre-processing unit comprises:

a processing unit that processes said grouped data by creating predetermined random phases within the range of zero and mathematical symbol 2pi, using said phases to generate a sequence of length equaling time domain index of said major group with the resulting sequence being unique from at least a second major group of at least a second stream having the same sub- stream index as the first stream and sharing the same channel as said first stream, using complex exponent of said phases to multiply and rotate phases of said data with same sub-stream index-. A transmitter for transmitting at least one stream of signals through a communication channel or a communication medium that is being shared with at least another transmitter or another stream,

wherein said transmitter comprises:

wherein said pre-processing unit comprises:

a processing unit that processes said grouped data by creating predetermined random matrices, using said matrices for each time index to generate a sequence of matrices having a time domain length equaling time domain length of said major group, resulting said sequence of matrices being unique from at least a second sequence of matrices of a second major group of at least a second stream having the same said two sub-stream indices as the first stream's two sub-stream indices, said second stream sharing the same channel as said first stream, using said sequence of matrices having said at least two sub-stream indices to multiply said frequency domain vector, generating a matrix-modified at least two sub-stream of data.

wherein said transmitter comprises:

wherein said pre-processing unit comprises:

a processing unit that processes said grouped data by creating predetermined random matrices having at least two time domain indices, using said matrices for each of said least two time domain indices to generate a sequence of matrices having same sub-carrier index as the major group, resulting said sequence of matrices being unique from at least a second sequence of matrices of a second major group of at least a second stream having the same said one sub-stream index as the first stream's sub-stream index, said second stream sharing the same channel as said first stream, using said sequence of matrices having said at least two time domain indices to multiply said frequency domain vector, generating a matrix-modified at sub-stream of data.

[Claim 10] A transmitter for transmitting at least one stream of signals through a communication channel or a communication medium that is being shared with at least another transmitter or another stream,

wherein said transmitter comprises:

a dividing unit that divides said at least one stream into at least one sub- stream to create a two dimensional map of data with sub-stream dimension having a sub-stream index and a time dimension having a time domain index;

wherein said pre-processing unit comprises:

a classifying unit that classifies data on two dimensional space of sub- stream domain and time domain into groups using a combination of at least two of methods of creating groups according to claim 2 or claim 5 or claim 9, processing the sections of said two dimensional space according to grouping format such that section of said map grouped according to claim 2 are processed according to claim 2, section of said map grouped according to claim 4 are processed according to claim 4, and section of said map grouped according to claim 5 are processed according to claim 5.