Capacity allocation in a multicarrier system

Claim 2

A method according to claim 1, characterized in that in said full capacity step, a said individual capacity number for a said carrier is obtained by comparing a signal noise ratio value measured on said carrier with required signal noise ratio values for allocating integer numbers of said data elements to said carrier, said required signal noise ratio values being listed in a 'required SNR per data element'-table.

Claim 3

A method according to claim 1, characterized in that said full capacity step comprises for each said carrier a first substep wherein a signal noise ratio value (SNRi) is measured on said carrier, a second substep wherein said measured signal noise ratio value (SNRi) is compared with required signal noise ratio values (SNRreq) for allocating integer numbers of said data elements to said carriers, a third substep wherein said individual capacity number is determined as being an integer number whose associated said required signal noise ratio value (SNRreq) is lower than said measured signal noise ratio value (SNRi) but larger than or equal to all said required signal noise ratio values (SNRreq) which are lower than said measured signal noise ratio value (SNRi), and a fourth substep wherein said individual capacity number of said data elements is allocated to said carrier.

Claim 4

A method according to claim 1, characterized in that said capacity fine tuning step in case of undercapacity comprises a first substep wherein for each said carrier a required power boost (Bi) is calculated, said required power boost (Bi) being equal to SNRreq' - SNRi, wherein SNRreq' represents a required signal noise ratio value which allows to allocate an additional data element to said carrier and wherein SNRi represents a signal noise ratio value measured on said carrier, a second substep wherein in said set of carriers, said carrier whose said required power boost (Bi) is minimal is determined, a third substep wherein a said additional data element is allocated to said carrier with minimal said required power boost (Bi), and a fourth substep wherein an overall power boost equal to said minimal required power boost (Bi) is applied to each said carrier which forms part of said set of carriers, said first, second, third and fourth substeps being repeated until said undercapacity is eliminated.

Claim 5

A method according to claim 1, characterized in that said capacity fine tuning step in case of overcapacity comprises a first substep wherein for each said carrier an additional noise margin (ANMi) is calculated, said additional noise margin (ANMi) being equal to SNRi - SNRreq, wherein SNRi represents a signal noise ratio value measured on said carrier, and wherein SNRreq represents a required signal noise ratio value to allow allocating to said carrier its individual capacity number of data elements, a second substep wherein in said set of carriers, said carrier whose additional noise margin (ANMi) is minimal is determined, and a third substep wherein a said data element allocated previously to said carrier with minimal said additional noise margin (ANMi) is removed therefrom, said first, second and third substep being repeated until said overcapacity is eliminated.

Claim 6

A method according to claim 1, characterized in that said method further includes a pseudo-overcapacity fine tuning step executed in case a last said additional data element allocated to a said carrier in said capacity fine tuning step in case of undercapacity comprises more said data bits than necessary to eliminate said undercapacity, said pseudo-overcapacity step comprising a first substep wherein for each said carrier occupied by data elements which comprise less data bits than said last allocated data element an additional noise margin (ANMi) is calculated, said additional noise margin being equal to SNRi - SNRreq, wherein SNRi represents a signal noise ratio value measured on said carrier, and wherein SNRreq represents a required signal noise ratio value to allow allocating thereto the number of data elements previously allocated thereto in said full capacity step and said capacity fine tuning step, a second substep wherein amongst said carriers occupied by data elements which comprise less data bits than said last allocated data element, said carrier whose additional noise margin (ANMi) is minimal is determined, and a third substep wherein a said data element which comprises less data bits is removed from said carrier with minimal said additional noise margin (ANMi).

Claim 7

A program module for an allocation processing unit (APU') for allocating a number of data elements, grouped in a packet of data elements called a data symbol and each of said data elements comprising at least one data bit, to a set of carriers to be modulated thereon and to be transmitted via a telecommunication line, said program module containing a set of control instructions, characterized in that said set of control instructions is structured to control a sequence of operations in said allocation processing unit (APU') in such a way that in a first phase, the full capacity phase, for each carrier in said set of carriers an individual capacity number is determined, said individual capacity number being equal to a maximum amount of data elements that may be allocated to said carrier, and to each said carrier said individual capacity number of data elements is allocated, and in a second phase, the capacity fine tuning phase, in case of undercapacity, i.e. in case said number of data elements grouped in a said data symbol is larger than an overall capacity number, said overall capacity number being equal to the sum of individual capacity numbers of all said carriers, said overall capacity number is enlarged and additional data elements are allocated to said set of carriers in accordance to a predetermined capacity enlarging rule, and in case of overcapacity, i.e. in case said number of data elements grouped in a said data symbol is smaller than said overall capacity number, some of said data elements are removed from carriers in said set of carriers according to a predetermined data removing rule.

Claim 8

An allocation processing unit (APU') provided to calculate a distribution of a number of data bits which constitute a data symbol over a set of carriers, said allocation processing unit (APU') being provided with a first input (NI') whereto said number is applied and a second input (MI') whereto carrier property information is applied, characterized in that said allocation processing unit (APU') includes a memory means (MEM) a first part (MM) of which being provided to store said carrier property information, a second part (MR) of which being provided to store carrier requirement information, and a third part (MD) of which being provided to store data allocation information, i.e. the amount of said data bits being assigned to each said carrier in said set, a first comparator means (C1), coupled at its first input (C1I1) to an output (O1) of said first part (MM) of said memory means (MEM) and at its second input (C1I2) to an output (O2) of said second part (MR) of said memory means (MEM), said first comparator means (C1) being provided to compare said carrier property information with said carrier requirement information, to thereby obtain individual carrier capacities for said carriers, and to apply said individual carrier capacities via an output (C1O) to a processing unit (PR) included in said allocation processing unit (APU') and coupled at its output (PO) to an input (I1) of said third part (MD) of said memory means (MEM), said processing unit (PR) being adapted to apply to said third part (MD) of said memory means (MEM) said data allocation information wherein for each said carrier said amount of data bits allocated thereto equals said individual carrier capacity of said carrier, and that said allocation processing unit (APU') further includes a second comparator means (C2), coupled at its first input (C2I1) to an output (O5) of said third part (MD) of said memory means (MEM) and at its second input (C2I2) to said first allocation processing unit input (NI'), said second comparator means (C2) being adapted to compare said number of data bits which constitute a data symbol with an overall capacity number of said set of carriers, said overall capacity number being equal to a sum of said individual carrier capacities, and to thereby, in a capacity fine tuning step, activate said processing unit (PR) to assign additional data elements to said carriers in accordance with a predetermined capacity enlarging rule in case of undercapacity and to remove data elements from said carriers in accordance with a predetermined data removing rule in case of overcapacity.

Claim 9

A multicarrier modulator (MOD) for modulation of data elements applied to an input (DI) thereof on a set of carriers for transmission thereof in a communication network coupled to an output (MO) thereof, said modulator (MOD) including between said input (DI) and said output (MO) a cascade connection of a mapping unit (MAP), an inverse fast fourier transform processing unit (IFFT), a cyclic prefix adder (CPA), a parallel to serial converter (PSC) and a digital to analog converter (DAC), said mapping unit (MAP) being provided to allocate said data elements to said set of carriers and to thereby generate a frequency domain parallel sequence of data, said inverse fast fourier transform processing unit (IFFT) being included to inverse fast fourier transform said frequency domain parallel sequence of data applied to its input and to thereby generate a time domain parallel sequence of data, said cyclic prefix adder (CPA) being provided to add a cyclic prefix to said time domain parallel sequence of data to compensate for intersymbol interference due to transmission over transmission lines in said communication network, said parallel to serial converter (PSC) being adapted to convert said time domain parallel sequence of data into a serial sequence of data which is applied to said digital to analog converter included to transform said serial sequence of data into an analog signal and to supply said analog signal to said output (MO) of said modulator (MOD), said mapping unit (MAP) including an allocation processing unit (APU) provided to generate a distribution of a number of data bits which constitute a data symbol over a set of carriers, said allocation processing unit (APU) being provided with a first input (NI) whereto said number is applied and a second input (MI) whereto carrier property information is applied, and a data allocation unit (DAU), an input of which is coupled to said modulator input (DI) and another input of which is coupled to an output (O) of said allocation processing unit (APU), said data allocation unit (DAU) provided to allocate said data elements, based on said distribution generated by said allocation processing unit (APU), to said set of carriers, characterized in that said allocation processing unit (APU) includes a memory means a first part of which being provided to store said carrier property information, a second part of which being provided to store carrier requirement information, and a third part of which being provided to store data allocation information, i.e. the amount of said data bits being assigned to each said carrier in said set, a first comparator means, coupled at its first input to an output of said first part of said memory means and at its second input to an output of said second part of said memory means, said first comparator means being provided to compare said carrier property information with said carrier requirement information, to thereby obtain individual carrier capacities for said carriers, and to apply said individual carrier capacities via an output to a processing unit included in said allocation processing unit (APU) and coupled at its output to an input of said third part of said memory means, said processing unit being adapted to apply to said third part of said memory means said data allocation information wherein for each said carrier said amount of data bits allocated thereto equals said individual carrier capacity of said carrier, and that said allocation processing unit (APU) further includes a second comparator means, coupled at its first input to an output of said third part of said memory means and at its second input to said first allocation processing unit input (NI), said second comparator means being adapted to compare said number of data bits which constitute a data symbol with an overall capacity number of said set of carriers, said overall capacity number being equal to a sum of said individual carrier capacities, and to thereby, in a capacity fine tuning step, activate said processing unit to assign additional data elements to said carriers in accordance with a predetermined capacity enlarging rule in case of undercapacity and to remove data elements from said carriers in accordance with a predetermined data removing rule in case of overcapacity.