Signal generation method and signal generation device

• US 9,281,883 B2
• Filed: 09/09/2015
• Issued: 03/08/2016
• Est. Priority Date: 12/10/2010
• Status: Active Grant

• Current Assignee: Sun Patent Trust
• Original Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Inventors: Murakami, Yutaka, Kimura, Tomohiro, Ouchi, Mikihiro
• Primary Examiner(s): Huynh, Dung B
• Application Number:
  US14/848,936
• Publication Number:
  US 20150381251A1
• Time in Patent Office: 181 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 11/10 Adding special bits or symbols to the coded information, e.g. parity check, casting out 9's or 11's
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0482 Adaptive codebooks
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/0682 using phase diversity (e.g. phase sweeping)
• CPC Class Codes: H04B 7/0697 using spatial multiplexing
• CPC Class Codes: H04L 1/0058 Block-coded modulation
• CPC Class Codes: H04L 25/0224 using sounding signals
• CPC Class Codes: H04L 25/03898 codebook-based design selection of codebook or precoding matrix for MIMO diversity systems H04B7/0456
• CPC Class Codes: H04L 25/067 providing soft decisions, i.e. decisions together with an estimate of reliability H04L25/068 and H04L25/069 take precedence; sequence estimation techniques H04L25/03178
• CPC Class Codes: H04L 27/2627 Modulators
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource

Abstract

A transmission method simultaneously transmitting a first modulated signal and a second modulated signal at a common frequency performs precoding on both signals using a fixed precoding matrix and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.

Claims

1. A transmission method of a transmission system, the transmission system having a first transmitter and a second transmitter, the transmission method comprising:

encoding input data to coded blocks each made up of a plurality of bits by using a predetermined error correction block coding scheme;

modulating each of the coded blocks to a first modulated signal s1 and a second modulated signal s2;

applying precoding by a fixed matrix F to the first modulated signal s1 and the second modulated signal s2 to obtain a first pre-coded signal z1′ and

a second pre-coded signal z2′

, wherein

the matrix F is expressed as;

2. The transmission method of claim 1, wherein

in a case that data included in the first modulated signal s1 is same as data included in the second modulated signal s2,

the first transmitter performs at least one of:

applying precoding by the fixed matrix F, where α

represents 0;

transmitting (i) the first transmission signal z1 from the first antenna at the first period at the first frequency, and

the second transmitter performs at least one of;

applying precoding by the fixed matrix F, where α

represents 0; and

transmitting (i) the second transmission signal z2 from the second antenna at the first period at the first frequency.

3. The transmission method of claim 1, wherein

in a case that data included in the first modulated signal s1 is different from data included in the second modulated signal s2,

the first transmitter performs at least one of:

applying precoding by the fixed matrix F, where α

represents a positive real number larger than 0; and

transmitting (ii) the first transmission signal z1 from the first antenna at the first period at the first frequency and the second transmission signal z2 from the third antenna at the first period at the first frequency; and

the second transmitter performs at least one of;

applying precoding by the fixed matrix F, where α

represents a positive real number larger than 0; and

transmitting (ii) the first transmission signal z1 from the second antenna at the first period at the first frequency and the second transmission signal z2 from the forth antenna at the first period at the first frequency.

4. A transmission system comprising:

a first transmitter; and

a second transmitter,

wherein both the first transmitter and the second transmitter are operable to;

encode input data to coded blocks each made up of a plurality of bits by using a predetermined error correction block coding scheme;

modulate each of the coded blocks to a first modulated signal s1 and a second modulated signal s2;

apply precoding by a fixed matrix F to the first modulated signal s1 and the second modulated signal s2 to obtain a first pre-coded signal z1′ and

a second pre-coded signal z2′

, wherein

the matrix F is expressed as;

5. The transmission system of claim 4, wherein

in a case that data included in the first modulated signal s1 is same as data included in the second modulated signal s2,

the first transmitter is operable to:

apply precoding by the fixed matrix F, where α

represents 0; and

transmit (i) the first transmission signal z1 from the first antenna at the first period at the first frequency; and

the second transmitter is operable to;

apply precoding by the fixed matrix F, where α

represents 0; and

transmit (i) the second transmission signal z2 from the second antenna at the first period at the first frequency.

6. The transmission system of claim 4, wherein

in a case that data included in the first modulated signal s1 is different from data included in the second modulated signal s2,

the first transmitter is operable to:

apply precoding by the fixed matrix F, where α

represents a positive real number larger than 0; and

transmit (ii) the first transmission signal z1 from the first antenna at the first period at the first frequency and the second transmission signal z2 from the third antenna at the first period at the first frequency; and

the second transmitter is operable to;

apply precoding by the fixed matrix F, where α

represents a positive real number larger than 0; and

transmit (ii) the first transmission signal z1 from the second antenna at the first period at the first frequency and the second transmission signal z2 from the forth antenna at the first period at the first frequency.

7. A reception method of a reception apparatus, the method comprising:

acquiring a reception signal obtained by receiving (i) a first transmission signal z1 transmitted from a first antenna of a first transmitter at a first period at a first frequency and a second transmission signal z2 transmitted from a second antenna of a second transmitter at the first period at the first frequency, or (ii) the first transmission signal z1 transmitted from the first antenna of the first transmitter at the first period at the first frequency and the second transmission signal z2 transmitted from a third antenna of the first transmitter at the first period at the first frequency, the first transmission signal z1 and the second transmission signal z2 having been generated through a predetermined generation process; and

demodulating the reception signal to reception data, through a demodulation process corresponding to the predetermined generation process, wherein

at least one of the acquiring and the demodulating is performed by the reception apparatus, and

the predetermined generation process is a process of;

encoding input data to coded blocks each made up of a plurality of bits by using a predetermined error correction block coding scheme;

modulating each of the coded blocks to a first modulated signal s1 and a second modulated signal s2;

applying precoding by a fixed matrix F to the first modulated signal s1 and the second modulated signal s2 to obtain a first pre-coded signal z1′ and

a second pre-coded signal z2′

, wherein

the matrix F is expressed as;

8. The reception method of claim 7, wherein

in a case of acquiring a reception signal obtained by receiving (i) the first transmission signal z1 transmitted from the first antenna of the first transmitter at the first period at the first frequency and the second transmission signal z2 transmitted from the second antenna of the second transmitter at the first period at the first frequency,

the predetermined generation process is a process of:

precoding by using the fixed matrix F, where α

represents 0, and

the reception apparatus demodulates the first modulated signal s1 included in the reception signal to first reception data and demodulates the second modulated signal s2 included in the reception signal to second reception data, the first reception data is same as the second reception data.

9. The reception method of claim 7, wherein

in a case of acquiring a reception signal obtained by receiving (ii) the first transmission signal z1 transmitted from the first antenna of the first transmitter at the first period at the first frequency and the second transmission signal z2 transmitted from the third antenna of the first transmitter at the first period at the first frequency,

the predetermined generation process is a process of:

applying precoding by the fixed matrix F, where α

represents a positive real number larger than 0, and

the reception apparatus demodulates the first modulated signal s1 included in the reception signal to first reception data and the second modulated signal s2 included in the reception signal to second reception data, the first reception data differing from the second reception data.

10. A reception apparatus comprising:

a memory; and

control circuitry,

wherein the control circuitry is operable to perform the steps of;

acquiring a reception signal obtained by receiving (i) a first transmission signal z1 transmitted from a first antenna of a first transmitter at a first period at a first frequency and a second transmission signal z2 transmitted from a second antenna of a second transmitter at the first period at the first frequency, or (ii) the first transmission signal z1 transmitted from the first antenna of the first transmitter at the first period at the first frequency and the second transmission signal z2 transmitted from a third antenna of the first transmitter at the first period at the first frequency, the first transmission signal z1 and the second transmission signal z2 having been generated through a predetermined generation process; and

demodulating the reception signal to reception data, through a demodulation process corresponding to the predetermined generation process, wherein

at least one of the acquiring and the demodulating is performed by the control circuitry, and

the predetermined generation process is a process of;

encoding input data to coded blocks each made up of a plurality of bits by using a predetermined error correction block coding scheme;

modulating each of the coded blocks to a first modulated signal s1 and a second modulated signal s2;

applying precoding by a fixed matrix F to the first modulated signal s1 and the second modulated signal s2 to obtain a first pre-coded signal z1′ and

a second pre-coded signal z2′

, wherein

the matrix F is expressed as;

11. The reception apparatus of claim 10, wherein

in a case of acquiring a reception signal obtained by receiving (i) the first transmission signal z1 transmitted from the first antenna of the first transmitter at the first period at the first frequency and the second transmission signal z2 transmitted from the second antenna of the second transmitter at the first period at the first frequency,

the predetermined generation process is a process of:

applying precoding by the fixed matrix F, where α

represents 0, and

the control circuitry demodulates the first modulated signal s1 included in the reception signal to first reception data and demodulates the second modulated signal s2 included in the reception signal to second reception data, the first reception data is same as the second reception data.

12. The reception apparatus of claim 10, wherein

in a case of acquiring a reception signal obtained by receiving (ii) the first transmission signal z1 transmitted from the first antenna of the first transmitter at the first period at the first frequency and the second transmission signal z2 transmitted from the third antenna of the first transmitter at the first period at the first frequency:

the predetermined generation process is a process of;

applying precoding by the fixed matrix F, where α

represents a positive real number larger than 0, and

the control circuitry demodulates the first modulated signal s1 included in the reception signal to first reception data and the second modulated signal s2 included in the reception signal to second reception data, the first reception data differing from the second reception data.