Efficient implementations of proposed turbo code interleavers for third generation code division multiple access

A method of interleaving, comprising:

• receiving and temporarily storing data in sequential locations in a memory;
• storing a plurality of addresses in a table;
• providing a counter electrically coupled to said table;
• selecting ones of said plurality of addresses using a pseudo-random sequence according to said counter;
• discarding selected ones of said plurality of addresses which are greater than a frame size, using a puncturing device electrically coupled to said table;
• and,
• retrieving said data from non-discarded ones of said plurality of address locations in said memory;
• synchronizing said data retrieval and said counter using clock.

An apparatus for interleaving, comprising:

• memory means for receiving temporarily storing data;
• counter means for counting;
• table storage means for storing a plurality of addresses and for selecting ones of said plurality of addresses using a pseudo-random sequence according to said counter;
• puncturing means electrically coupled to said table means for discarding said ones of said selected plurality of addresses that are greater than a frame size;
• and
• memory readout means electrically coupled to said puncturing means for retrieving said data from said memory means at said ones of said selected plurality of addresses which are not discarded;
• buffer means for outputting said data retrieved from said memory means;
• and
• clock means coupled to said buffer means and said counter means for synchronizing said buffer means and said counter means.

A turbocode interleaver for interleaving elements of frames of data wherein a frame consists of N elements where N is a positive integer greater than one, the interleaver comprising:

• a memory for storing elements in addressable locations and for retrieving the elements from the addressable locations,
• wherein elements are stored in locations according to a first sequence of addresses which is a consecutive sequence, and elements are retrieved according to a second sequence of addresses;
• a clock for producing a clock signal;
• a first counter advanced by the clock signal for counting up through a value N2 where N2 is a positive integer;
• a second counter advanced by carries from the first counter for counting up through a value N1 where the product of N1 and N2 is a positive integer at least equal to N;
• an address generator for producing the second sequence of addresses as a pseudo-random sequence according to the first and second counters;
• a puncture circuit for suppressing retrieval of data from memory locations corresponding to values of a product of the first counter and the second counter that are greater than N;
• and
• a buffer for:
• receiving N elements retrieved from the memory according to the second sequence of addresses, and
• forwarding the N elements at a rate determined by the clock signal.

Apparatus for interleaving elements of frames of data wherein a frame consists of N elements where N is a positive integer greater than one, the apparatus comprising:

• storage means for storing elements in addressable locations and for retrieving the elements from the addressable locations,
• wherein elements are stored in locations according to a first sequence of addresses which is a consecutive sequence, and elements are retrieved according to a second sequence of addresses;
• clock means for producing a clock signal;
• first counter means advanced by the clock signal for counting up through a value N2 where N2 is a positive integer;
• second counter means advanced by carries from the first counter means for counting up through a value N1 where the product of N1 and N2 is a positive integer at least equal to N;
• address generation means for producing the second sequence of addresses as a pseudo-random sequence according to the first and second counter means;
• puncturing means for suppressing retrieval of data from storage means locations corresponding to values of a product of the first counter and the second counter that are greater than N;
• and
• buffer means for:
• receiving N elements retrieved from the storage means according to the second sequence of addresses, and
• forwarding the N elements at a rate determined by the clock signal.

A method of interleaving elements of frames of data wherein a frame consists of N elements where N is a positive integer greater than one, the interleaver comprising:

• storing elements in addressable locations and for retrieving the elements from the addressable locations,
• wherein elements are stored in locations according to a first sequence of addresses which is a consecutive sequence, and elements are retrieved according to a second sequence of addresses;
• producing a clock signal;
• counting occurrences of the clock signal in a first count up through a value N2 where N2 is a positive integer;
• counting carries from the first count in a second count up through a value N1 where the product of N1 and N2 is a positive integer at least equal to N;
• producing the second sequence of addresses as a pseudo-random sequence according to the first and second counts;
• suppressing retrieval of elements corresponding to values of a product of the first counter and the second counter that are greater than N;
• buffering N elements retrieved according to the second sequence of addresses;
• and
• forwarding the N elements at a rate determined by the clock signal.

A method of interleaving, comprising:

• receiving and temporarily storing data in sequential locations in a memory;
• storing a plurality of addresses in a table;
• providing a counter electrically coupled to said table;
• selecting ones of said plurality of addresses according to said counter;
• discarding selected ones of said plurality of addresses which are greater than a frame size, using a puncturing device electrically coupled to said table;
• retrieving said data from non-discarded ones of said plurality of address locations in said memory;
• synchronizing said data retrieval and said counter using a clock;
• reversing a set of bits received from said counter;
• multiplying said reversed set of counter bits by an offset, wherein said offset is a predetermined number greater than zero;
• generating a plurality of other memory addresses by combining said offset reversed set of counter bits with non-punctured ones of said plurality of addresses;
• and,
• retrieving said data from said plurality of other memory address locations in said memory.

An apparatus for interleaving, comprising:

• memory means for receiving temporarily storing data;
• counter means for counting;
• table storage means for storing a plurality of addresses and for furnishing ones of said addresses in a sequence according to said counter;
• puncturing means electrically coupled to said table means for discarding said ones of said selected plurality of addresses that are greater than a frame size;
• memory readout means electrically coupled to said puncturing means for retrieving said data from said memory means at said ones of said selected plurality of addresses which are not discarded;
• buffer means for outputting said data retrieved from said memory means;
• clock means coupled to said buffer means and said counter means for synchronizing said buffer means and said counter means;
• bit reverser means electrically coupled to said counter means for reversing a set of bits from said counter means;
• multiplier means electrically coupled to said bit reverser means for offsetting said set of reversed counter bits, wherein said offset is a predetermined number greater than zero;
• combiner means electrically coupled to said puncturing means and said multiplier means for generating a plurality of other memory addresses by combining said offset reversed set of counter bits with non-punctured ones of said plurality of addresses;
• and,
• said memory means for retrieving said data from said plurality of other memory addresses.