Method and apparatus for channel aggregation and single sideband transmission

A method for image reject reception and channel separation executed in a broadband communication system (300,500), wherein the method comprises:

• receiving (S1) a single sideband transmission signal (SRF) containing N radio frequency channels, wherein N is an integer equal or greater than 1;
• downconverting (S2) the transmission signal (SRF) into a first and a second intermediate frequency broadband signals (IF0°,IF90°), wherein the intermediate frequency signals are frequency interleaved broadband signals, and wherein the second intermediate frequency signal) (IF90°) is phase shifted by 90° or −90° relative to the first intermediate frequency broadband signal (IF0°);
• performing (S3) in a first channel debonder (501) N IQ demodulations and a separation of the first intermediate frequency broadband signal (IF0°) into N baseband IQ signal pairs, wherein each downconverter uses a different local oscillator frequency;
• performing (S4) in a second channel debonder (502) N IQ demodulation and a separation of the second intermediate frequency broadband signal (IF90°) into N baseband IQ signal pairs, wherein each demodulator uses the same local oscillator frequencies used in the first channel debonder but shifted by 90° or −90°;
• and
• superposing (S5) the downconverted baseband IQ signal pairs at the output of the first and second channel debonder (501,502) to generate the I and Q component of all N baseband channels and deleting their images.

A transmitter (300) comprising a first and a second channel bonder (301,302) and a single sideband transmitter (303) for transmitting N baseband signals,

• wherein the first channel bonder (301) comprises N IQ modulators (305a-b), wherein each IQ modulator comprises a first local oscillator (308a-b) for upconverting each baseband signal to an individual intermediate frequency signal defined by the frequency of the local oscillator (308a-b) of the corresponding IQ modulator (305a-b);
• and wherein the first channel bonder (301) further comprises an adder (311) for superposing the intermediate frequency signals of all IQ modulators to perform channel aggregation and to generate a first intermediate frequency broadband signal (IF0°);
• wherein the second channel bonder (302) comprises N IQ modulators (305c-d), wherein each IQ modulator comprises a second local oscillator (308c-d) for upconverting each baseband signal to an individual intermediate frequency signal defined by the frequency of the local oscillator (308c-d) of the corresponding IQ modulator (305c-d);
• wherein the second local oscillators (308c-d) output the same center frequencies for each base band signal as the first local oscillators (308a-b) in the first channel bonder (301) but shifted by 90° or by −90°;
• and wherein the second channel bonder (302) further comprises an adder (312) for superposing the intermediate frequency signals of all IQ modulators to perform channel aggregation to generate a second intermediate frequency broadband signal (IF90°);
• and
• wherein the single sideband transmitter (303) comprises a local oscillator (314) and mixers (313,315) utilizing the first and second intermediate frequency broadband signals) (IF0°,IF90°) to generate a transmission signal (SRF).

A receiver comprising a first and a second channel debonder (501,502) and an image reject receiver (503) for receiving a transmission signal (SRF),

• wherein the image reject receiver (503) comprises a local oscillator (507) and mixers (504,506) utilizing transmission signal (SRF) to generate a first and a second intermediate frequency broadband signal (IF0°,IF90°) having the same frequency but are phase shifted by 90° or −90°;
• wherein the first and second intermediate frequency broadband signal (IF0°,IF90°) contain N baseband signals having individual center frequencies (fc,n);
• wherein the first channel debonder (501) comprises N IQ demodulators (509a-b), wherein each IQ demodulator comprises mixers (511a-b;512a-b) and a first local oscillator (513a-b) oscillating at the center frequency (fc,n) of one of the N baseband signals for downconverting the first intermediate frequency broadband signal IF0° into baseband signals;
• wherein the second channel debonder (502) comprises N IQ demodulators (509c-d), wherein each IQ demodulator comprises mixers (511c-d;512c-d) and a second local oscillator (513c-d) oscillating at the center frequency (fc,n) of one of the N baseband signals for downconverting the second intermediate frequency broadband signal (IF90°) into baseband signals;
• wherein the second local oscillators (513c-d) output the same center frequencies (fc,n) for each baseband signal as the first local oscillators (513a-b) in the first channel debonder (501) but shifted by 90° or by −90°;
• and
• wherein the receiver further comprises adders (516-519) for superposing the baseband signals provided by the first and second channel debonder (501,502) to generate I and Q components of the baseband signals and rejecting their images.