Transmission apparatus, reception apparatus and digital radio communication method

• US 10,270,631 B2
• Filed: 11/29/2016
• Issued: 04/23/2019
• Est. Priority Date: 07/28/1999
• Status: Expired due to Fees

• Current Assignee: Redwood Technologies, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: WIFI One LLC
• Inventors: Murakami, Yutaka, Takabayashi, Shinichiro, Orihashi, Masayuki, Matsuoka, Akihiko
• Primary Examiner(s): Jain, Ankur
• Application Number:
  US15/363,162
• Publication Number:
  US 20170078123A1
• Time in Patent Office: 875 Days
• CPC Class Codes: H04B 1/38 Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0006 by adapting the transmission format
• CPC Class Codes: H04L 27/12 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04L 27/206 using a pair of orthogonal carriers, e.g. quadrature carriers
• CPC Class Codes: H04L 27/34 Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
• CPC Class Codes: H04L 27/3455 in order to facilitate carrier recovery at the receiver end, e.g. by transmitting a pilot or by using additional signal points to allow the detection of rotations

Abstract

A transmission apparatus and method include modulating a transmission signal using a first modulation scheme selected from a plurality of modulation schemes to generate a first symbol sequence. A second symbol, generated using a phase shift keying (PSK) modulation scheme, is inserted in the first symbol sequence to generate a first modulation signal for transmission. A second modulation signal is received that includes a third symbol generated using a PSK modulation scheme and inserted in a second symbol sequence generated using a second modulation scheme selected from the plurality of modulation schemes. The third symbol is extracted from the received modulation signal. A transmission path associated with the received modulation signal is estimated using the third symbol. A received data signal from the second symbol sequence included in the received modulation signal is output using the estimated transmission path.

Claims

1. Radio communications apparatus comprising a transceiver configured to:

modulate a transmission signal using a first modulation scheme selected from a plurality of modulation schemes to generate a first symbol sequence;

insert a second symbol, generated using a phase shift keying (PSK) modulation scheme, in the first symbol sequence to generate a first modulation signal for transmission;

receive a second modulation signal that includes a third symbol generated using a PSK modulation scheme and inserted in a second symbol sequence generated using a second modulation scheme selected from the plurality of modulation schemes;

extract the third symbol from the received modulation signal;

estimate a transmission path associated with the received modulation signal using the third symbol; and

output a received data signal from the second symbol sequence included in the received modulation signal using the estimated transmission path.

2. The radio communications apparatus according to claim 1, wherein the plurality of modulation schemes include M-ary modulation schemes of two or more kinds.

3. The radio communications apparatus according to claim 1, wherein the PSK modulation scheme is a binary phase shift keying (BPSK) modulation or a quadrature phase shift keying (QPSK) modulation.

4. The radio communications apparatus according to claim 1, wherein the first symbol sequence is arranged on a time axis.

5. The radio communications apparatus according to claim 1, wherein the second symbol sequence is arranged on a time axis.

6. The radio communications apparatus according to claim 1, wherein the first symbol comprises a quadrature baseband signal.

7. The radio communications apparatus according to claim 1, wherein the transmission apparatus is configured to change an insertion interval of the second symbol in the first symbol sequence to generate the first modulation signal.

8. The radio communications apparatus according to claim 1, wherein the second modulation scheme is selected based on condition of transmission path of the second modulation signal.

9. The radio communications apparatus according to claim 1, wherein the second symbol or the third symbol is for one of more of:

estimation of distortion of transmission path of the received modulation signal,

calculation of a phase and an amount of frequency offset in the received modulation signal,

synchronization of timing between the receiver apparatus and the transmission apparatus, and

correction of errors in the received modulation signal.

10. A radio communications method performed using a transceiver, comprising the steps of:

modulating a transmission signal using a first modulation scheme selected from a plurality of modulation schemes to generate a first symbol sequence;

inserting a second symbol, generated using a phase shift keying (PSK) modulation scheme, in the first symbol sequence to generate a first modulation signal for transmission;

receiving a second modulation signal that includes a third symbol generated using a PSK modulation scheme and inserted in a second symbol sequence generated using a second modulation scheme selected from the plurality of modulation schemes;

extracting the third symbol from the received modulation signal;

estimating a transmission path associated with the received modulation signal using the third symbol; and

outputting a received data signal from the second symbol sequence included in the received modulation signal using the estimated transmission path.

11. The radio communications method according to claim 10, wherein the plurality of modulation schemes include M-ary modulation schemes of two or more kinds.

12. The radio communications method according to claim 10, wherein the PSK modulation scheme is a binary phase shift keying (BPSK) modulation or a quadrature phase shift keying (QPSK) modulation.

13. The radio communications method according to claim 10, wherein the first symbol sequence is arranged on a time axis.

14. The radio communications method according to claim 10, wherein the second symbol sequence is arranged on a time axis.

15. The radio communications method according to claim 10, wherein the first symbol comprises a quadrature baseband signal.

16. The radio communications method according to claim 10, further comprising the transceiver changing an insertion interval of the second symbol in the first symbol sequence to generate the first modulation signal.

17. The radio communications method according to claim 10, further comprising the transceiver selecting the second modulation scheme based on condition of transmission path of the second modulation signal.

18. The radio communications method according to claim 10, wherein the second symbol or the third symbol is for one of more of:

estimation of distortion of transmission path of the received modulation signal,

calculation of a phase and an amount of frequency offset in the received modulation signal,

synchronization of timing between the receiver apparatus and the transmission apparatus, and

correction of errors in the received modulation signal.