SIGNAL GENERATION METHOD AND SIGNAL GENERATION DEVICE

• US 20130121306A1
• Filed: 11/29/2011
• Published: 05/16/2013
• 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
• Granted Patent: US 8,867,482 B2
• Time in Patent Office: Days
• US Class Current: 370/330
• 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 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:

generating M first encoded blocks usable as a first set of bits and M second encoded blocks usable as a second set of bits using a predetermined error-correcting block coding method, where M is a natural number;

performing a change of phase on each of a first baseband signal s1 generated from the first set of bits and a second baseband signal s2 generated from the second set of bits, thus generating a first post-phase change baseband signal s1′ and

a second post-phase change baseband signal s2′

, each including M symbols; and

applying weighting to the first post-phase change baseband signal s1′ and

to the second post-phase change baseband signal s2′

according to a predetermined matrix F, thus generating the plurality of signals for transmission on the common frequency band and at the common time as a combination of M pairs of 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(s1′

,s2′

)^T

and the change of phase is performed on the first baseband signal s1 and the second baseband signal s2 using a phase modification value sequentially selected from among N phase modification value candidates.

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:

an encoder generating M first encoded blocks usable as a first set of bits and M second encoded blocks usable as a second set of bits using a predetermined error-correcting block coding method, where M is a natural number;

a phase changer performing a change of phase on each of a first baseband signal s1 generated from the first set of bits and a second baseband signal s2 generated from the second set of bits, thus generating a first post-phase change baseband signal s1′ and

a second post-phase change baseband signal s2′

, each including M symbols; and

a weighting unit applying weighting to the first post-phase change baseband signal s1′ and

to the second post-phase change baseband signal s2′

according to a predetermined matrix F, thus generating the plurality of signals for transmission on the common frequency band and at the common time as a combination of M pairs of 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(s1′

,s2′

)^T

and the change of phase is performed on the first baseband signal s1 and the second baseband signal s2 using a phase modification value sequentially selected from among N phase modification value candidates.