Optimum UMTS modem

• US 20020138807A1
• Filed: 03/26/2001
• Published: 09/26/2002
• Est. Priority Date: 03/26/2001
• Status: Abandoned Application

• Current Assignee: Quang Nguyen
• Original Assignee: Quang Nguyen
• Inventors: Nguyen, Quang
• Application Number:
  US09/681,360
• Publication Number:
  US 20020138807A1
• Time in Patent Office: Days
• US Class Current: 714/792
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/0066 Parallel concatenated codes
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems

Abstract

The present invention encompasses several improved methods and architecture of an UMTS modem for delivering optimum high-speed broadband information, commerce and multimedia entertainment services to mobile users via fixed, wireless and satellite IP networks. The present invention utilizes Turbo Codes baseband processor for optimum performance in decoding received data in limited power and noisy environments. The present invention provides a method for dividing the high-speed bit-stream into multiple slow-speed sub bit-streams, and also dividing the UMTS broadband channel into multiple sub-channels for transmitting each sub bit-stream in the assigned adjacent sub-channels, and the uses of the Orthogonal Frequency Division Multiplexing method implemented by N-point complex FFT/iFFT processor in which it effectively divides the broadband high-speed channel into multiple slow-speed N sub-channels where multiple adjacent channels transmit their carriers'"'"' frequency which are orthogonal to each other. Also, when M is smaller than N, channels hopping can be done by reassigning a bit-stream to another sub-channel slot.

Claims

1. An optimum units modem for multimedia data, voice, VolP in wireless internet applications comprising of:

an UMTS modem transmitter;

an UMTS modem receiver;

an N-point complex FFT processor and an N-point complex iFFT processor for implementing the multiple sub-channels with Orthogonal Frequency Division Multiplexing method;

a Turbo Codes baseband processor for optimum performance in decoding of noisy receive data, and encoding transmit data;

an 8-PSK Mapper for mapping a 3-bit symbol into a point on the 8-PSK constellations with the I and Q component values;

an 8-PSK De-mapper for converting the received set (I,Q) values from the complex FFT processor into soft-decision values for the Turbo Code baseband processor;

an M-bit serial-to-parallel (S/P) converter for segmenting the input bit-stream into an M number of sub bit-streams;

an M-bit parallel-to-serial (P/S) converter for shifting the decoded data to the output;

a Channel Selector and a Channel De-selector for assigning bit-streams into sub-channels, and also controlling the channel hopping function;

a GI adder and a GI remover for adding and removing guard intervals from the I and Q sequences of samples;

a Symbol wave shaper;

an IQ Modulator for modulating the I and Q sequences of samples and adding them into a transmit signal;

an IQ Demodulator for demodulating the receive signal and producing the I and Q sequences of N samples; and

an AFC Clock Recovery circuitry for clock synchronization.

2. The UMTS modem system of claim cl, wherein the Turbo Codes baseband processor uses SISO 8-state Log-MAP decoder for high-speed and optimum decoding a plurality of sequences of the receive samples.

3. The UMTS modem system of claim c1, wherein the 8-PSK De-mapper produces soft-decision values output.

4. The UMTS modem system of claim c1, wherein the complex FFT/iFFT processors sub-divide the UMTS broadband channel into multiple sub-channels by using the Orthogonal Frequency Division Multiplexing method.

5. The UMTS modem system of claim c1, wherein the M-bit serial-to-parallel (S/P) converter sub-divides the high-speed R-Mbps input to generate the multiple slow-speed S-Mbps M sub bit-streams;

where S-Mbps is equal to R-Mbps divide by N.

6. The UMTS modem system of claim c1, further provides a method to divide the UMTS broadband into multiple sub-channels and the uses of an Orthogonal Frequency Division Multiplexing method implemented by N-point complex FFT/iFFT processors where multiple adjacent channels transmit their carriers'"'"' frequency which are orthogonal to each other.

7. The UMTS modem system of claim c1, further provides a method to divide high-speed bit-stream into multiple slow-speed sub bit-streams for transmitting over the sub-channels.

8. The UMTS modem system of claim c1, further provides a method to control channels hopping by re-assign bitstream into another sub-channel.

9. A method for UMTS modem transmitting a plurality of high-speed digital information generated from a MAC layer into wireless IP networks comprising the steps of:

(1) sub-divide the high-speed R-Mbps input serial data by shifting it into the M-bit serial-to-parallel (S/P) converter to generate the multiple slow-speed S-Mbps M sub bit-streams;

(2) encode each bit of each bit-streams independently with a Turbo Codes encoder, with coding rate ⅓ and

constraint length K=4, to generate a 3-bit symbol (one data bit and two parity bits);

(3) map the 3-bit symbol into an 8-PSK constellations points to select the values of its I and Q components;

at this point, all the sub bit-streams are done the same as the above step (2), (3);

(4) select a point in the N-point complex iFFT and map the I component into its real part and the Q component into its imaginary par accordingly;

(5) perform the invert complex N-point Fast Fourier Transform to produces the two I and Q sequences of N samples corresponding to the real and imaginary of the complex iFFT products;

(6) add the guard interval to the I and Q sequences of N samples;

(7) modify the I and Q sequences of N samples with and FIR filter Symbol wave shaper;

(8) modulate the I sequence with a Sine carrier, and the Q sequence with a Cosine carrier;

(9) sum the two modulated I and Q with an adder to produce the transmit signal.

10. A method for UMTS modem receiving a plurality of high-speed digital information received from the wireless IP networks comprising the steps of:

(1) demodulate the receive signal with a local carrier to produce the I and Q sequences of N samples;

(2) remove the guard interval from the I and Q sequences of N samples;

(3) perform the complex N-point Fast Fourier Transform on the I and Q sequences of N samples to convert them into N complex points data;

(4) de-selector each of N complex point data for each set of (I,Q) values correspond to each of the M bit-streams;

(5) de-map each of the M complex point (I,Q) based on an 8-PSK constellations to produce soft-decision values;

(6) decode the soft-decision value with the Turbo Codes Decoder baseband processor, where data is iteratively decoded until a final decided hard-decoded bit is produced for the output correspond to each bit-stream;

at this point, all bit-streams are done with steps (5) and (6);

(7) latch all M decoded bits into the parallel-to-serial converter and shift out to the output.