Receiver, frame synchronization method, transmitter, transmission method, and program

A frame synchronization method, comprising the steps of:

• receiving, by a reception unit, signals of a frame having a preamble including a frame detection signal sequence, formed by a repetition of one type of known signal sequence of a first length, arranged in a head thereof and a frame synchronization signal sequence, formed by the one type of known signal sequence of the first length or an inverse sequence thereof, arranged subsequent to the frame detection signal sequence;
• performing, by a convolution arithmetic operation unit, convolution arithmetic operation of a known correlation sequence of a second length determined on the basis of a peak value of cross-correlation between the signal sequence and the frame synchronization signal sequence in the preamble and cross-correlation between a received signal sequence and the frame synchronization signal sequence at time preceding predetermined time by a period of time corresponding to a product of an integer greater than or equal to zero and less than a value representing the second length and a value representing the first length;
• and
• ensuring, by a synchronization unit, synchronization of the frame while regarding the predetermined time when a value more than or equal to a threshold value or a maximum value is obtained as a result of the convolution arithmetic operation as reception time of a last signal sequence that forms the frame synchronization signal sequence.

A program for causing a computer to execute processing, comprising the steps of:

• receiving, by a reception unit, signals of a frame having a preamble including a frame detection signal sequence, formed by a repetition of one type of known signal sequence of a first length, arranged in a head thereof and a frame synchronization signal sequence, formed by the one type of known signal sequence of the first length or an inverse sequence thereof, arranged subsequent to the frame detection signal sequence;
• performing, by a convolution arithmetic operation unit, convolution arithmetic operation of a known correlation sequence of a second length determined on the basis of a peak value of cross-correlation between the signal sequence and the frame synchronization signal sequence in the preamble and cross-correlation between a received signal sequence and the frame synchronization signal sequence at time preceding predetermined time by a period of time corresponding to a product of an integer greater than or equal to zero and less than a value representing the second length and a value representing the first length;
• and
• ensuring, by a synchronization unit, synchronization of the frame while regarding the predetermined time when a value more than or equal to a threshold value or a maximum value is obtained as a result of the convolution arithmetic operation as reception time of a last signal sequence that forms the frame synchronization signal sequence.

A transmitter, comprising:

• a preamble generation unit that generates a preamble including, a frame detection signal sequence formed by a repetition of one type of known signal sequence of a length L that is a first length, a frame synchronization signal sequence of a length N·L formed by two types of known signal sequences of a length L including the one type of known signal sequence or inverse sequences of the two types of known signal sequences, and a channel estimation signal sequence formed by the two types of known signal sequences and the inverse sequences, in the order mentioned,
• wherein, where a signal sequence of a length P·L formed by the frame synchronization signal sequence and leading signal sequences of the channel estimation signal sequence are used as a synchronization sequence used for frame synchronization,
• wherein the preamble, which satisfies that a maximum value of a difference between a value at a last bit position and a value at another position in the synchronization sequence of likelihood information obtained by performing convolution arithmetic operation of a known correlation sequence of a second length determined on the basis of a peak value of cross-correlation between the signal sequence of the preamble and the synchronization sequence and cross-correlation between a received signal sequence and the synchronization sequence at time preceding predetermined time by a period of time corresponding to a product of an integer greater than or equal to zero and less than a value representing the second length and a value representing the first length, satisfies any one of:
• 3·L, where P=2;
• 5·L, where P=3;
• 7·L, where P=4;
• 10·L, where P=5;
• 13·L, where P=6;
• and
• 16·L, where P=7.

A transmission method, comprising the step of:

• generating a preamble including, a frame detection signal sequence formed by a repetition of one type of known signal sequence of a length L that is a first length, a frame synchronization signal sequence of a length N·L formed by two types of known signal sequences of a length L including the one type of known signal sequence or inverse sequences of the two types of known signal sequences, and a channel estimation signal sequence formed by the two types of known signal sequences and the inverse sequences, in the order mentioned,
• wherein, where a signal sequence of a length P·L formed by the frame synchronization signal sequence and leading signal sequences of the channel estimation signal sequence are used as a synchronization sequence used for frame synchronization,
• the preamble, which satisfies that a maximum value of a difference between a value at a last bit position and a value at another position in the synchronization sequence of likelihood information obtained by performing convolution arithmetic operation of a known correlation sequence of a second length determined on the basis of a peak value of cross-correlation between the signal sequence of the preamble and the synchronization sequence and cross-correlation between a received signal sequence and the synchronization sequence at time preceding predetermined time by a period of time corresponding to a product of an integer greater than or equal to zero and less than a value representing the second length and a value representing the first length, satisfies any one of:
• 3·L, where P=2;
• 5·L, where P=3;
• 7·L, where P=4;
• 10·L, where P=5;
• 13·L, where P=6;
• and
• 16·L, where P=7.

A program for causing a computer to execute processing, including the step of:

• generating a preamble including, a frame detection signal sequence formed by a repetition of one type of known signal sequence of a length L that is a first length, a frame synchronization signal sequence of a length N·L formed by two types of known signal sequences of a length L including the one type of known signal sequence or inverse sequences of the two types of known signal sequences, and a channel estimation signal sequence formed by the two types of known signal sequences and the inverse sequences, in the order mentioned,
• wherein, where a signal sequence of a length P·L formed by the frame synchronization signal sequence and leading signal sequences of the channel estimation signal sequence are used as a synchronization sequence used for frame synchronization,
• the preamble, which satisfying that a maximum value of a difference between a value at a last bit position and a value at another position in the synchronization sequence of likelihood information obtained by performing convolution arithmetic operation of a known correlation sequence of a second length determined on the basis of a peak value of cross-correlation between the signal sequence of the preamble and the synchronization sequence and cross-correlation between a received signal sequence and the synchronization sequence at time preceding predetermined time by a period of time corresponding to a product of an integer greater than or equal to zero and less than a value representing the second length and a value representing the first length, satisfies any one of:
• 3·L, where P=2;
• 5·L, where P=3;
• 7·L, where P=4;
• 10·L, where P=5;
• 13·L, where P=6;
• and
• 16·L, where P=7.