METHOD OF SIGNAL GENERATION AND SIGNAL GENERATING DEVICE

• US 20130121307A1
• Filed: 01/20/2012
• Published: 05/16/2013
• Est. Priority Date: 02/18/2011
• 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
• Granted Patent: US 8,885,596 B2
• Time in Patent Office: Days
• US Class Current: 370/330
• CPC Class Codes: H04B 7/0667 of delayed versions of same signal using 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: H04B 7/0842 Weighted combining
• CPC Class Codes: H04L 1/0048 in conjunction with detection of multiuser or interfering signals, e.g. iteration between CDMA or MIMO detector and FEC decoder for spatial equalizer H04L25/03286
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 27/20 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04L 27/2634 Inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators in combination with other circuits for modulation
• CPC Class Codes: H04L 27/26524 Fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators in combination with other circuits for demodulation
• CPC Class Codes: H04L 27/368 adaptive predistortion
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0082 at predetermined intervals
• CPC Class Codes: H04L 5/12 the signals being represented by different phase modulations of a single carrier

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 signal generation method for generating, from a plurality of baseband signals, a plurality of signals for transmission on a common frequency band and at a common time, comprising the steps of:

multiplying a first baseband signal s1 generated from a first set of bits by u, and multiplying a second baseband signal s2 generated from a second set of bits by v, where u and v denote real numbers different from each other;

performing a change of phase on each of the first baseband signal s1 multiplied by u and the second baseband signal s2 multiplied by v, thus generating a first post-phase-change baseband signal u×

s1′ and

a second post-phase-change baseband signal v×

s2′

; and

applying weighting according to a predetermined matrix F to the first post-phase-change baseband signal u×

s1′ and

to the second post-phase-change baseband signal v×

s2′

, thus generating the plurality of signals for transmission on the common frequency band and at the common time as a first weighted signal z1 and a second weighted signal z2, wherein

the first weighted signal z1 and the second weighted signal z2 satisfy the relation;

(z1,z2)^T=F(u×

s1′

,v×

s2′

)^T

and the change of phase is performed on the first baseband signal s1 multiplied by u and the second baseband signal s2 multiplied by v by using a phase modification value sequentially selected from among N phase modification value candidates, each of the N phase modification value candidates being selected at least once within a predetermined period.

2. A signal generation apparatus for generating, from a plurality of baseband signals, a plurality of signals for transmission on a common frequency band and at a common time, comprising:

a power changer multiplying a first baseband signal s1 generated from a first set of bits by u, and multiplying a second baseband signal s2 generated from a second set of bits by v, where u and v denote real numbers different from each other;

a phase changer performing a change of phase on each of the first baseband signal s1 multiplied by u and the second baseband signal s2 multiplied by v, thus generating a first post-phase-change baseband signal u×

s1′ and

a second post-phase-change baseband signal v×

s2′

; and

a weighting unit applying weighting according to a predetermined matrix F to the first post-phase-change baseband signal u×

s1′ and

to the second post-phase-change baseband signal v×

s2′

, thus generating the plurality of signals for transmission on the common frequency band and at the common time as a first weighted signal z1 and a second weighted signal z2, wherein

the first weighted signal z1 and the second weighted signal z2 satisfy the relation;

(z1,z2)^T=F(u×

s1′

,v×

s2′

)^T

and the change of phase is performed on the first baseband signal s1 multiplied by u and the second baseband signal s2 multiplied by v by using a phase modification value sequentially selected from among N phase modification value candidates, each of the N phase modification value candidates being selected at least once within a predetermined period.