Digital radio communication system and method

• US 20010017896A1
• Filed: 02/22/2001
• Published: 08/30/2001
• Est. Priority Date: 02/25/2000
• Status: Active Grant

• Current Assignee: Redwood Technologies, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Takabayashi, Shinichiro, Murakami, Yutaka, Orihashi, Masayuki, Matsuoka, Akihiko, Abe, Katsuaki
• Granted Patent: US 6,985,538 B2
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 27/26 Systems using multi-frequency codes H04L27/32 takes precedence
• CPC Class Codes: H04L 27/34 Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems

Abstract

QPSK modulated quadrature baseband signal generating section 301 generates a QPSK modulated quadrature baseband signal. 8 PSK modulated quadrature baseband signal generating section 302 generates an 8 PSK modulated quadrature baseband signal. Based on the modulation scheme determined information, in-phase component switching section 304 and quadrature component switching section 305 switch between the QPSK modulated quadrature baseband signal, 8 PSK modulated quadrature baseband signal and pilot symbol to output to radio section 306. Radio section 306 performs the predetermined radio processing on the baseband signal to output a transmission signal. The transmission signal is amplified in power amplifier 307, and the amplified transmission signal is transmitted from transmission antenna 309. It is thereby possible to take into account both the improvement in the data transmission rate, and the benefit and convenience in terminals.

Claims

1. A digital radio communication system in which a base station apparatus determines a modulation scheme corresponding to a propagation environment from at least two kinds of modulation schemes including a multi-level modulation scheme with a modulation level of 16 or more where amplitude is provided with information, and modulates transmission data with the determined modulation scheme to transmit to a terminal apparatus, while said terminal apparatus determines a modulation scheme corresponding to the propagation environment from at least two kinds of phase modulation schemes, and modulates transmission data with the determined modulation scheme to transmit to said base station apparatus.

8. The digital radio communication system according to

claim 1

, wherein when said base station apparatus modulates the transmission data with the multi-level modulation scheme with the modulation level of 16 or more where amplitude is provided with information and transmits the data in a frame structure in which a pilot symbol comprised of a single symbol is inserted in every three or more successive information symbols, each of the number of signal points of a symbol immediately before the pilot symbol and the number of signal points of another symbol immediately after the pilot symbol is two or more, and is less than the number of signal points of each of other information symbols.

9. The digital radio communication system according to

claim 1

, wherein when said base station apparatus modulates the transmission data with 8 PSK and transmits the data in a frame structure in which a pilot symbol comprised of a single symbol is inserted in every three or more successive information symbols, each of the number of signal points of a symbol immediately before the pilot symbol and the number of signal points of another symbol immediately after the pilot symbol is two or more, and is less than the number of signal points of each of other information symbols.

10. The digital radio communication system according to

claim 1

, wherein when said terminal apparatus modulates the transmission data with 8 PSK and transmits the data in a frame structure in which a pilot symbol is inserted in every three or more successive information symbols, each of the number of signal points of a symbol immediately before the pilot symbol and the number of signal points of another symbol immediately after the pilot symbol is two or more, and is less than the number of signal points of each of other information symbols.

2. A digital radio communication system in which a base station apparatus determines a modulation scheme corresponding to a propagation environment from at least two kinds of modulation schemes including a multi-level modulation scheme with a modulation level of 16 or more where amplitude is provided with information, and modulates transmission data with the determined modulation scheme to transmit to a terminal apparatus, while said terminal apparatus modulates transmission data with a predetermined phase modulation scheme to transmit to said base station apparatus.

3. A digital radio communication system in which a base station apparatus modulates transmission data with a multi-level modulation scheme with a modulation level of 16 or more where amplitude is provided with information to transmit to a terminal apparatus, while said terminal apparatus determines a modulation scheme corresponding to a propagation environment from at least two kinds of phase modulation schemes, and modulates transmission data with the determined modulation scheme to transmit to said base station apparatus.

4. A digital radio communication system in which a base station apparatus transmits transmission data to a terminal apparatus with a multi-carrier system, while said terminal apparatus transmits transmission data to said base station apparatus with a single-carrier system.

6. The digital radio communication system according to

claim 4

, wherein said base station apparatus determines a modulation scheme corresponding to a propagation environment from at least two kinds of modulation schemes including a multi-level modulation scheme with a modulation level of 16 or more where amplitude is provided with information, and modulates transmission data of each sub-carrier with the determined modulation scheme to transmit to said terminal apparatus.

7. The digital radio communication system according to

claim 4

, wherein said terminal apparatus determines a modulation scheme corresponding to a propagation environment from at least two kinds of phase modulation schemes, and modulates transmission data with the determined modulation scheme to transmit to said base station apparatus.

5. A digital radio communication system in which a base station apparatus transmits transmission data to a terminal apparatus with an OFDM system, while said terminal apparatus transmits transmission data to said base station apparatus with a single-carrier system.